A Concise Guide To
Compression & Limiting by Paul White
Settings and Characteristics
Threshold
Ratio
Hardknee
Attack
Autoattack/ Release
Holdtime
Stereo Link
All in the ear
Using compressors
Side Effects
De-Essing
Introduction Compression and
limiting have been covered before, but like the brown mould that you blitz
every few months in the bathroom only to watch gradually return, questions on
the subject steadily build up again, mere months after we explain the basic
principles in an article such as this one! On the one hand, musicians are
encouraged to give an enthusiastic and dynamic performance, while on the other,
their levels must be controlled to some extent, if we are to create musically
acceptable mixes. One tool that is vital in helping us to do this is the
compressor, but before looking at how they work, I'd like to outline the types
of problems they are designed to solve. While the faders on a mixer can be used
to set the overall balance of the voices and instruments that make up a piece
of music, short term changes such as the occasional loud guitar note or
exuberant vocal scream are less easy to deal with manually. When I first
started recording, compressors were too expensive for home use, so we had no
alternative but to 'ride' the faders. Once you've used a compressor to control
your levels, however, you come to appreciate that there are certain things it
can do that the human engineer is just too slow to manage. For example, unless
you've played the track through and memorised exactly where the loud and quiet
spots are, you'll always respond too late, because you can't start to move the
fader until you hear that something is wrong. A compressor, on the other hand,
will be aware of a level problem virtually as soon as it happens. Fortunately,
good compressors are now relatively inexpensive, and next to reverb, a
compressor is probably the most important studio processor to own-at least for
those who work with vocals or a lot of acoustic instruments. For the benefit of
those who are still a little unsure as to what a compressor does, it simply
reduces the difference between the loudest and quietest parts of a piece of
music by automatically turning down the gain when the signal 19519e412t gets past a
predetermined level. In this respect, it does a similar job to the human hand
on the fader-but it reacts much faster and with greater precision, allowing it
to bring excessive level deviations under control almost instantaneously.
Unlike the human operator though, the compressor has no feel or intuition; it
simply does what you set it up to do, which makes it very important that you
understand what all the variable parameters do and how they affect the final
sound. In order to react quickly enough, the compressor dispenses with the
human ear and instead monitors the signal level by electronic means. A part of
the circuit known as the 'side chain' follows the envelope of the signal,
usually at the compressor's output, and, uses this to generate a control signal
which is fed into the gain control circuit. When the output signal rises past
an acceptable level, a control signal is generated and the gain is turned down.
Figure 1 shows a simplified block diagram of a typical compressor circuit.
Threshold: With manual gain
riding, the level above which the signal becomes unacceptably loud is
determined by the engineer's discretion: if it sounds too loud to him, he turns
it down. In the case of a compressor, we have to 'tell' it when to intervene,
and this level is known as the Threshold. In a conventional compressor, the
Threshold is varied via a knob calibrated in dBs, and a gain reduction meter is
usually included so we can see how much the gain is being modified. If the
signal level falls short of the threshold, no processing takes place and the
gain reduction meter reads OdB. Signals exceeding the Threshold are reduced in
level, and the amount of reduction is shown on the meter. This means the signal
peaks are no longer as loud as they were, so in order to compensate, a further
stage of 'make-up' gain is added after compression, to restore or 'make up' any
lost gain.
Ratio: When the input signal
exceeds the Threshold set by the operator, gain reduction is applied, but the
actual amount of gain reduction depends on the 'Ratio' setting. You will see
the Ratio expressed in the form 4:1 or similar, and the range of a typical
Ratio control is variable from 1:1 (no gain reduction all) to infinity:1, which
means that the output level is never allowed to rise above the Threshold
setting. This latter condition is known as limiting, because the Threshold, in
effect, sets a limit which the signal is not allowed to exceed. Ratio is based
on dBs, so if a compression ratio of 3:1 is set, an input signal exceeding the
Threshold by 3dB will cause only a 1 dB increase in level at the output. In
practice, most compressors have sufficient Ratio range to allow them to
function as both compressors and limiters, which is why they are sometimes
known by both names. The relationship between Threshold and Ratio is shown in
Figure 2, but if you're not comfortable with dBs or graphs, all you need to
remember is that the larger the Ratio, the more gain reduction is applied to
any signal exceeding the Threshold.
Hardknee: This is not a
control or parameter, but rather a characteristic of certain designs of
compressor. With a conventional compressor, nothing happens until the signal
reaches the Threshold, but as soon as it does, the full quota of gain reduction
is thrown at it, as determined by the Ratio control setting. This is known as
hard knee compression, because a graph of input gain against output gain will
show a clear change in slope (a sharp angle) at the Threshold level, as is
evident from Figure 2. Other types of compressor utilise a soft knee characteristic,
where the gain reduction is brought in progressively over a range of 1OdB or
so. What happens is that when the signal comes within 1OdB or so of the
Threshold set by the user, the compressor starts to apply gain reduction, but
with a very low Ratio setting, so there's very little effect. As the input
level increases, the compression Ratio is automatically increased until at the
Threshold level, the Ratio has increased to the amount set by the user on the
Ratio control. This results in a gentler degree of control for signals that are
hovering around the Threshold point, and the practical outcome is that the
signal sounds less obviously processed. This attribute makes soft-knee models
popular for processing complete mixes or other sounds that need subtle control.
Hard knee compression can sometimes be heard working, and if a lot of gain
reduction is being applied, they can sound quite heavy-handed. In some
situations, it can make for an interesting sound-take Phil Collins' or Kate
Bush's vocal sounds, for example. The dotted curve on the graph in Figure 2
shows a typical soft-knee characteristic.
Attack: The attack time is
how long a compressor takes to pull the gain down, once the input signal has
reached or exceeded the Threshold level. With a fast attack setting, the signal
is controlled almost immediately, whereas a slower attack time will allow the
start of a transient or percussive sound to pass through unchanged, before the
compressor gets its act together and does something about it. Creating a deliberate
overshoot by setting an attack time of several milliseconds is a much-used way
of enhancing the percussive characteristics of instruments such as guitars or
drums. For most musical uses, an initial attack setting of between 1 and 20 mS
is typical. However, when treating sound such as vocals, a fast attack time
generally gives the best results, because it brings the level under control
very quickly, producing a more natural sound. Release: The Release sets how
long it takes for the compressor's gain to come back up to normal once the
input signal has fallen back below the Threshold. If the release time is too
fast, the signal level may 'pump'-in other words, you can hear the level of the
signal going up and down. This is usually a bad thing, but again, it has its
creative uses, especially in rock music. If the release time is too long, the
gain may not have recovered by the time the next 'above Threshold' sound
occurs. A good starting point for the release time is between 0.2 and 0.6
seconds.
Auto Attack/Release: Some
models of compressor have an Auto mode, which adjusts the attack and release
characteristics during operation to suit the dynamics of the music being
processed. In the case of complex mixes or vocals where the dynamics are
constantly changing, the Auto mode may do a better job than fixed manual
settings. Peak/RMS operation: Every compressor uses a circuit known as a side
chain, and the side chain's job in life is to measure how big the signal is, so
that it knows when it needs compressing. This information is then used to
control the gain circuit, which may be based around a Voltage-controlled
Amplifier (VCA), a Field Effect Transistor (FET) or even a valve. The
compressor will behave differently, depending on whether the side chain responds
to average signal levels or to absolute signal peaks. An RMS level detector
works rather like the human ear, which pays less attention to short duration,
loud sounds than to longer sounds of the same level. Though RMS offers the
closest approximation to the way in which our ears respond to sound, many
American engineers prefer to work with Peak, possibly because it provides a
greater degree of control. And though RMS provides a very natural-sounding
dynamic control, short signal peaks will get through unnoticed, even if a fast
attack time is set, which means the engineer has less control over the absolute
peak signal levels. This can be a problem when making digital recordings, as
clipping is to be avoided at all costs. The difference between Peak and RMS
sensing tends to show up most on music that contains percussive sounds, where
the Peak type of compressor will more accurately track the peak levels of the
individual drum beats. Another way to look at it is to say that the greater the
difference between a signal's peak and average level, the more apparent the
difference between RMS and peak compression/limiting will be. On a sustained
pad sound with no peaks, there should be no appreciable difference. Peak
sensing can sometimes sound over-controlled, unless the amount of compression
used is slight. It's really down to personal choice, and all judgements should
be based on listening tests.
Holdtime: A compressor's side
chain follows the envelope of the signal being fed into it, but if the attack
and release times are set to their fastest positions, it is likely that the
compressor will attempt to respond not to the envelope of the input signal but to
individual cycles of the input waveform. This is particularly significant when
the input signal is from a bass instrument, as the individual cycles are
relatively long, compared to higher frequencies. If compression of the
individual waveform cycles is allowed to occur, very bad distortion is audible,
as the waveform itself gets reshaped by the compression process. We could
simply increase the release time of the compressor so that it becomes too slow
to react to individual cycles, but sometimes it's useful to be able to set a
very fast release time. A better option is to use the Hold time control, if you
have one. Hold introduces a slight delay before the release phase is initiated,
which prevents the envelope shaper from going into release mode until the Hold
time has elapsed. If the Hold time is set longer than the duration of a single
cycle of the lowest audible frequency, the compressor will be forced to wait
long enough for the next cycle to come along, thus avoiding distortion. A Hold
time of 50ms will prevent this distortion mechanism causing problems down to
20Hz. If your compressor doesn't have a separate Hold time control, it may
still have a built-in, preset amount of Hold time. A 50ms hold time isn't going
to adversely affect any other aspect of the compressor's operation, and leaves
the user with one less control to worry about.
Stereo Link: When processing
stereo signals, it is important that both channels are treated equally, for the
stereo image will wander if one channel receives more compression than the
other. For example, if a loud sound occurs only in the left channel, then the
left channel gain will be reduced, and everything else present in the left
channel will also be turned down in the mix. This will result in an apparent
movement towards the right channel, which is not undergoing so much gain
reduction. The Stereo Link switch of a dual-channel compressor simply forces
both channels to work together, based either on an average of the two input
signals, or whichever is the highest in level at any one time. Of course, both
channels must be set up exactly the same for this to work properly, but that's
taken care of by the compressor. When the two channels are switched to stereo,
one set of controls usually becomes the master for both channels-though some
manufacturers opt for averaging the two channel's control settings, or for
reacting to whichever channel's controls are set to the highest value.
All in the ear: You may have
noticed, or at least read about, the fact that different makes of compressor
sound different. But if all they're really doing is changing level, shouldn't
they all sound exactly the same? As we've already learned, part of the reason
is related to the shape of the attack and release curves of the compressor, and
of course peak sensing will produce different results to RMS, but at least as
important is the way in which a compressor distorts the signal. Technically
perhaps, the best compressor is one that doesn't add any distortion, but most
engineers seem to like the 'warm' sound of the older valve designs which, on
paper, are blighted by high distortion levels. The truth is that low levels of
distortion have a profound effect on the way in which we perceive sound, which
is the principle on which aural exciters work. A very small amount of
even-harmonic distortion can tighten up bass sounds, while making the top end seem
brighter and cleaner. The best-sounding contemporary compressor designs include
valve models with a degree of distortion built in, while others use FETs, which
mimic the behaviour of valve circuits. As digital recorders and mixers are
introduced into the signal chain, more people are becoming interested in
equipment that can put the warmth back into what they perceive as an
over-clinical sound.
Using compressors: One
problem newcomers to recording seem to have is deciding where in their system
to patch the compressor. A compressor is a processor rather than an effect, so
it should be used via an insert point or be patched in-line with a line-level
signal. If you have a system without insert points and you want to compress a
mic input, you may be able to use your foldback (pre-fade send) in an
unconventional way to get around the problem, as shown in Figure 3. Here's how
to do it: Plug the mic into a mixer channel, set the mic gain level as normal,
but turn the channel fader completely down. Turn the pre-fade aux send control
to around three-quarters up, and do the same with the pre-fade master control,
if there is one. Turn the pre-fade send fully down on all the other channels.
Now you can take your mic signal (now boosted to line level), from the pre-fade
send output, feed it into the compressor and bring it back into another channel
of the mixer-this time into the line input. And there you have it: your
compressed mic signal. Most engineers will normally add some compression to
vocals while recording, and then add more if necessary while mixing. Working
this way makes good use of the tape's dynamic range, while helping to prevent
signal peaks from overloading the tape machine. It is best to use rather less
compression than might ultimately be needed while recording, so that a little
more can be added at the mixing stage if required. If too much compression is
added at the beginning, there's little you can do to get rid of it afterwards.
Similarly, if you have a compressor with a gate built-in, it might be better to
leave this off when recording, and only use it while mixing. This will prevent
a good take from being wrecked by an inappropriate gate setting. A further
benefit of gating during the mix is that the gate will remove any tape hiss,
along with the original recorded noise. If a gate is allowed to close too
rapidly, it can chop off the ends of wanted sounds that have long decays,
especially those with long reverb tails, so most gates (and expanders) fitted
to compressors have either a switchable long/short release time, or a proper
variable-release time control.
Stereo Link: When processing
stereo signals, it is important that both channels are treated equally, for the
stereo image will wander if one channel receives more compression than the other.
For example, if a loud sound occurs only in the left channel, then the left
channel gain will be reduced, and everything else present in the left channel
will also be turned down in the mix. This will result in an apparent movement
towards the right channel, which is not undergoing so much gain reduction. The
Stereo Link switch of a dual-channel compressor simply forces both channels to
work together, based either on an average of the two input signals, or
whichever is the highest in level at any one time. Of course, both channels
must be set up exactly the same for this to work properly, but that's taken
care of by the compressor. When the two channels are switched to stereo, one
set of controls usually becomes the master for both channels-though some
manufacturers opt for averaging the two channel's control settings, or for
reacting to whichever channel's controls are set to the highest value.
Side Effects: Most of the
sound energy in a typical piece of music occupies the low end of the audio
spectrum, which is why your VU meters always seem to respond to the bass drum
and bass guitar. High frequency sounds tend to be much lower in level and so
rarely need compressing, but even so, high-frequency sounds in the mix are
still brought down in level whenever the compressor reacts to loud bass sounds.
For example, a quiet hi-hat occurring at the same time as a loud bass drum beat
will be reduced in level. One technique to reduce the severity of this effect
is to set a slightly longer attack time on the compressor, to allow the attack
of the hi-hat to get through before the gain reduction occurs. This is only a
partial solution, and if heavy compression is applied to a full mix, the
overall sound can become dull, as the high-frequency detail is reduced in level.
Going back to the subjective effect of subtle harmonic distortion for a moment,
some compressor designs make use of harmonic distortion or dynamic equalisation
to provide an increase in high-frequency level whenever heavy compression is
taking place. This helps offset the dulling of high-frequency detail, and can
make a great subjective difference, but it isn't a perfect solution. More
elaborate compressors have been designed which split the signal into two or
more frequency bands and compress these separately. This neatly avoids the bass
end causing the high end to be needlessly compressed, but it can introduce
other problems related to phase, unless the design is extremely well
thought-out.
De-Essing: Another side
chain-related process is the de-essing of sibilant vocal sounds. Sibilance is
sometimes evident when people pronounce the letters 's' or 't', and is really a
high-pitched whistling caused by air passing around the teeth. If a parametric
equaliser is inserted into the side-chain signal path of a compressor and tuned
to boost the offending frequency, the compressor will apply more gain reduction
when sibilance is present than at other times. Most sibilance occurs in the 5
to 1OkHz region of the audio spectrum, so if the equaliser is tuned to this
frequency range and set to give around lOdB of boost, then in the selected
frequency range, compression will occur 1OdB before it does in the rest of the
audio spectrum. The equaliser should be set up by listening to the equaliser
output, and then tuning the frequency control until the sibilant part of the
input signal is strongest. Figure 4 shows how a compressor and equaliser may be
used as a de-esser. Some compressors have a built-in sweep equaliser, to allow
them to double as de-essers without the need for an external parametric
equaliser.
I should stress that these are just to get you started-the ideal settings vary
from compressor to compressor, which is why I come up with slightly different
figures every time I write on the subject. The more gain reduction is used, the
higher the level of background noise, so never use more gain reduction than is
necessary. Virtually all recorded pop music has a deliberately restricted
dynamic range, to make it sound loud and powerful when played over the radio.
The more a signal is compressed, the higher its average energy level. In
addition to compressing the individual tracks during recording or mixing, the
engineer may well have applied further compression to the overall mix. This can
be very effective, but don't choke the life out of a mix by over-compressing it
either. When it comes to individual tracks, it is pretty much routine to
compress vocals, bass guitars, acoustic guitars and occasionally electric
guitars, though overdriven guitar sounds tend to be self compressing anyway!
The most important of these to get right is the lead vocal, because even modest
dips in level can make the Iyrics difficult to hear over the backing. Sequenced
instruments are less likely to need compression, because you can control the
dynamics by manipulating the MIDI data in the sequencer. My own rule is to
avoid compression (or any other form of treatment) unless it's absolutely
necessary. Even with vocals, if somebody gives me a perfectly controlled vocal
take, I wouldn't want to compress it just because compressing vocals is the
done thing. Compression is a very valuable studio tool, but like all tools, it
is just a means to an end-not an end in itself
20 TIPS ON... MIXING PAUL WHITE delivers a crash course in instant mixing. The vocals sound great, the drums are really kicking and the guitars are exceptional, but put it all together and what have you got? A mess! Sound familiar? Until you've gained plenty of experience in mixing music, the process can seem very frustrating. There are probably as many correct ways to tackle a mix as there are successful engineers and producers. Even so, I've taken 20 tips that I've found to be helpful over the years and presented them below in the form of a checklist. These are not immutable rules, just general guidelines that can be broken any time you feel you can get away with it. Have fun! Put the mixer into neutral (EQ flat, aux sends down, routing to Left/Right only and so on), before you start work and pull down the faders on any channels not in use. Make sure all unused aux sends are set to zero and that unused mixer channels are unrouted as well as muted, as this will further reduce the level of background noise. If you don't do this, you may find effects on tracks that don't need effects, or unwanted tracks creeping into a bounce due to a routing button being left down. You should also have a track sheet for your recording from which you can label the mixer channels. The time-honoured way to do this is to use masking tape and felt pen, so that you can peel the whole lot off when the job is finished. Optimise the gain settings not only for the multitrack returns, but also for all effects sends and returns and for your external effect units. Also ensure that your master recorder is being driven as hard as possible, without overloading on signal peaks. These simple measures can significantly improve the clarity of your mix. If your recording is going to be digitally edited, leave any fade-outs until the edit stage, and don't try to chop off the noise that precedes or follows the mix -- you may need this when setting up a digital denoiser that requires a bare noise 'fingerprint' for calibration purposes. Subgroup logical sections of your mix, such as the drum kit or the backing vocals, so that you can control the overall level of the subgrouped elements from a single fader or stereo pair of faders. This allows you to control the mix using fewer faders, and fewer fingers! Be aware that any channels subgrouped this way must also have their effects routed to the same groups(s), otherwise the effects level won't change as you adjust the group fader. Where level adjustments need to be made, mark the fader settings with a chinagraph wax pencil and, if necessary, take note of the tape counter or timecode locations at which the level changes occur. This way you can solicit help from other musicians in the studio if the mix gets too busy. If you're lucky and are using mix automation, listen to the whole mix through without watching the levels, so that you can concentrate on the balance of the instruments. Don't assume that your ears always tell you the truth. Rest them before mixing and constantly refer to commercial recordings played over your monitor system, so that you have some form of reference to aim for. This is particularly important if you use harmonic enhancers, as your ears can grow used to the effects of over-enhancement very quickly. Don't overdo the effects, especially reverb, as this can clutter your recording and take away the contrast that is needed to give your mix punch. As a rule, the drier the sound, the more up-front it will sound, while heavily reverbed sounds tend to move into the background. If you need strong reverb on lead vocals, try to add some pre-delay to the reverb effect and adjust both the vocal level and reverb level so that the vocal sits comfortably over the backing. Don't pan bass sounds such as kick drums or bass instruments to the sides of the stereo soundstage, as these high energy sounds need to be shared equally between the two stereo speakers for best results. As a rule, very bassy sounds contain little or no directional information anyway, although bass sounds that also contain a lot of harmonics can sound more directional. Leave any final EQ and effect adjustments until the full mix is playing. If you work on any single instrument in isolation, it's likely to sound different when everything else is added. If you can avoid using any heavy EQ, the result is more likely to sound more natural. Try not to have too many instruments competing for the same part of the audio spectrum. The mid-range is particularly vulnerable, so try to choose the best sounds at source. You can improve the separation when mixing by using EQ to narrow the spectrum of the sound you're working with. Try rolling off some low end and occasionally taking out any excessive top end. This is sometimes known as spectral mixing, where each sound or instrument is given its own space in the audio spectrum. A good example of this is the acoustic guitar which, in a rock mix, can muddle the low mid. If you roll off the low end, you still get plenty of definition, but the mix will seem far cleaner. Sidechain filters on noise gates (set to Key Listen mode) are often very good tools for trimming the high and low ends of sounds without unduly changing the section you want to keep. Don't over EQ sounds as they're likely to sound unnatural, especially when boosting. As a rule, good external equalisers will sound better than your console channel EQ when you're trying to make significant tonal changes. If you can confine your EQ to gentle shelving cut or boost rather than using heavy sweep mid, you're less likely to end up with nasal, harsh or phasey sounds. If possible, fix problems by using EQ cut rather than boost. The human hearing system is less sensitive to EQ cut than it is to boost. This is especially true if you are using a low-cost equaliser or the EQ in your desk. Compress the vocals to make them sit nicely in the mix. Few vocalists can sing at a sufficiently even level to be mixed successfully without compression. Soft-knee compressors tend to be the least obtrusive, but if you want the compression to add warmth and excitement to your sound, try an opto-compressor or a hard-knee model with a higher ratio setting than you'd normally use. Be aware that compression raises the background noise (for every 1dB of gain reduction, the background noise in quiet passages will come up by 1dB), and heavy compression can also exaggerate vocal sibilance. From time to time, check your mix balance by listening from outside the studio/bedroom door. This tends to show up level imbalances more clearly than when listening from directly in front of the monitors. Nobody is quite sure why, but it works. Don't monitor too loudly. It may make the music seem more exciting (initially), but the end user is unlikely to listen at the same high level. High monitoring levels also tend temporarily to shift your hearing perspective and can lead to permanent hearing damage. It's fine to check the mix loudly for short periods, but most of the time, it's useful to try and mix at the level you think the music will eventually be played. (Forget I said this if you're mixing dance music for nightclubs!) Check your mixes on headphones as well as speakers. Headphones show up small distortions and clicks that you may never hear over loudspeakers. However, don't rely solely on headphones for mixing, for they represent the stereo image differently to loudspeakers and are notoriously unpredictable at low frequencies. Don't vary the level of the drums and bass unnecessarily during a mix, as the rhythm section is traditionally the constant backdrop against which other sounds move. Natural dynamics within rhythm instrument parts is OK, but don't keep moving the faders on these sounds. In a busy mix, try 'ducking' mid-range instruments such as overdrive guitars and synth pads under the control of the vocals, so that whenever the vocals are present, the conflicting sounds fall in level by two or three dBs. Just a little ducking can significantly improve the clarity of a mix. Use a fairly fast attack time for the ducker (which may be either a compressor or a noise gate that has ducking facilities), and set the release time by ear. Shorter release times will cause more obvious gain-pumping, but in rock mixes, this can add welcome energy and excitement. If you are recording a primarily MIDI-based track, try not to look at your sequencer display while mixing; the visual stimulus interferes with your ability to make subjective judgements based only on the sound. If necessary, close your eyes. Watching your sequencer progress through the arrange page can also give you a false impression of how well the arrangement is working, which is why some composers prefer hardware sequencers. If a close-miked sound seems unnaturally lifeless, but you don't want to add any obvious reverb, try an ambience or early reflection setting to induce a sense of space. The shorter the reverb time, the easier it is to move the treated sound to the front of your mix. Listen to your finished mix again the day after you've finished it, as your perception is likely to change after resting your ears overnight. Also check the master recording on as many different sound systems as you can, to ensure it sounds fine on all of them. Even then, save all your mix information and track sheets, including effects settings, as you never know when you might want to try to improve on the 'final mix'!
EQ 101 There are very few absolute
"Rights and Wrongs" when it comes to EQ. Basically, if it sounds good
to you, it's right. There are some generally accepted thoughts on the matter
though, so we'll go over some of them as starting points. One generally
accepted thought is that most vocal mics are very midrange heavy. Typically a
cut in the midrange along with a slight boost of the bass and treble
frequencies can compensate for this. Now remember, every voice is different, so
don't just set every vocal mic in your system to one setting and go. You have
to listen to the individual characteristics of each voice. If someone has a
deep, booming voice you may find yourself cutting the bass and boosting the
mids and highs. A female vocalist may have a very light, "airy" voice
and may need some help (boost) in the low and mid areas. "Sweep" type
or Parametric midrange controls are great because they let you "dial
in" the particular problem frequency and then boost or cut it. For
example, to find a problem frequency, you can turn the "level" control
of the mid-sweep to full cut and then sweep the "frequency" knob
until you find the exact frequency that you want to cut. Then re-adjust the
"level" knob to the actual amount of cut you want. Fully parametric
EQ's let you adjust the band-width as well. This is generally called a
"Q" adjustment and it determines how big of a chunk (in octaves) will
be cut or boosted. Typically these can be adjusted anywhere from 0.1 to a full
octave. Most mixers don't have fully parametric EQ, while semi-parametric EQ's
(no Q adjust) are quite common.
Another generally accepted thought is that there really isn't much below 40Hz
that anyone wants to hear live. On a recording it may be a different story, but
live you pretty much want to cut anything below 40Hz. This will do several
things: it will reduce stage rumble, reduce that "flabby, booming"
kick/bass sound, will increase headroom (which is the reserve power capability)
in your power amplifiers (because now they won't have to reproduce those power
robbing low frequencies), and generally clean up the whole mix. If your amp,
crossover or mixer has sub-sonic filters... use them! Those filters are the
quickest way to cut down on those unwanted low frequencies below 40 Hz. Also,
on midrange and treble instruments (vocals, horns, guitars, keys, etc.) use the
channel low cut (if available). These vary from 75Hz to 100Hz and give you all
of the above mentioned benefits without adversely affecting the sound. Now I
know that some 5 & 6 string bass players and keyboard players will insist
that there is desirable musical content below 40Hz. However, there are
harmonics and overtones that still let you hear the low "B" being
played on a 5 string bass, you just won't hear the fundamental (approx. 30Hz).
I think the trade-off (a clean, punchy mix) is worth it. You can decide for
yourself.Part of getting the sound you want is knowing where an instrument lies
in the frequency spectrum and part of it is just plain experimentation.
Most people know that a kick drum is a bass instrument right? Well, yes and no.
Most of what you hear from a kick drum is in the bass region, true, but try
boosting the kick at 1K. Hear that extra "snap" that you just added?
Or try boosting the snare around 250Hz. That midrange/treble drum suddenly
sounds huge and punchy. Bass guitar is often "mis EQ'd". Instead of
pumping up the low end until the windows shake loose, try cutting around 400Hz
to get rid of some "mud" and boosting around 1.5K to add some
"twang". The bass will cut through the mix with great definition and
still have plenty of low end. Some instruments (like a piano) cover a very wide
range of the spectrum and can be very difficult to EQ. I've seen sound people
use six EQs on a grand piano (4 channel mixer EQ, 2 outboard parametric). Of
course this probably means it wasn't mic'ed properly to begin with. Proper mic
selection and placement are necessary to get as close to the right sound as
possible so that major EQ work is not needed (but that's another article).
Electric or sampled pianos are pre-EQ'd and typically don't require as much work.
Maybe cut the bass a bit and boost the treble so it fits in the mix better
(keep in mind that a solo instrument should be treated differently and may not
require as much EQ, if any, as an instrument that you want to fit into a mix).
When trying to fit a lot of instruments into a mix, try what I call
"contrary" EQ. If the instrument is in the bass range, try boosting
the high-mid or treble frequencies, add some low end to a female vocal, or add
some "edge" to a male vocalist with a treble boost.
Graphic EQ's are usually used on the overall mix and in the monitor mix. For
the overall mix you would want to use a graphic EQ to fine tune your mix to a
particular room. If it's a "dead" room (acoustic tile ceiling, thick
carpet and full of people), you may want to boost the high end and/or cut some
low frequencies, if it's a "live" (hard floors, walls, ceiling, etc.)
room you may need to cut the high/mid and treble a bit. Typically, a 10 to 15
band graphic (2/3 to 1 octave) is sufficient for mains. For monitors you may
need a 30 band (1/3 octave) graphic EQ for each monitor mix. This type of
narrow-band fine tuning lets you precisely locate and cut frequencies that
cause "feedback", rumble, hum, etc. I could write fifty more pages
and not cover the half of it. Please remember that these are suggestions for
starting points and they are my personal opinions. Experiment and find out what
works best for you. Also remember there is no substitute for quality equipment.
If you use a poor sounding mic, mixer, amp, instrument, etc., no amount of EQ
will totally fix it.
Until next time, adios! - Doc S.
GIVING YOUR RECORDINGS A
'PRODUCED' SOUND Why is it that some perfectly well-recorded songs sound like demos,
while others sound like top commercial tracks? Paul White investigates the
mystery of the 'produced' sound. One of the questions we hear most from Sound
On Sound readers is "Why doesn't my music sound as 'produced' as the music
I hear on commercial CDs?" I'm sure you won't be too surprised when I tell
you that there isn't a single, simple answer. Some people assume that the
superior equipment used in pro studios is the key, but although competent gear
is required to do the job properly, you don't actually need anything esoteric.
Even when it comes to recording vocals you don't have to use expensive high-end
tube capacitor mics -- artists such as Phil Collins and Mick Jagger often use
relatively inexpensive dynamic models because that's what works best for them.
A few years ago, the drum sound was what gave away most demos, but now we have
good drum machines, drum samples and sample loops, as well as real drums, to
choose from. The secret of a produced sound starts with the source material. It
doesn't matter what you do to your recording afterwards if this isn't up to scratch.
It almost goes without saying that good timing and good tuning are essential,
but the choice of sounds and the way in which acoustic instruments and voices
are recorded has a huge bearing on the perceived quality of the end result.
Vox Clever If you record
vocals in a small, untreated room, the chances are that the resulting sound
will be boxy, so place your mic somewhere near the centre (but not exactly in
the centre) of a larger room and put up improvised screens (sleeping bags,
duvets, blankets and so on) where necessary to kill the reflections. Used in
this way, virtually any respectable mic will give you good results providing
you use a pop shield. You can also record acoustic guitars in the same
environment. Vocals invariably need compression, but what kind and how much?
Listen to what you've recorded and try to establish how much variation there is
in the vocal level. If you hear a lot of fluctuation it might be better to use
a model of compressor that can pin down the level without changing the sound
too much. The compressors that come as standard in Yamaha digital mixers are
good for this, as you can really pile on the gain reduction without changing
the sound too radically; there are also analogue models that can do the same.
On the other hand, you may feel the vocals need thickening as well as
levelling, in which case a compressor with a character of its own might be
better suited to the job. Tube and 'opto' compressors generally produce the
fattest sounds, and of course there are software plug-ins that emulate just
about anything you can buy in a rackmount box. The goal is to get the vocal
sitting nicely with the backing track so that you don't feel the urge to turn
it up or down in different parts of the song. Professional engineers may also spend
some time fine-tuning vocal levels with their mixer automation systems, and if
you use either a digital mixer or a computer-based recording system you can do
the same.
Key Facts Synth sounds must
be chosen with care, because a lot of factory patches are designed to sound big
and impressive for the benefit of those who choose their new instruments on the
strength of 'preset cruising'! What sounds wonderful on its own might take up
too much space in a mix so, if you don't want to edit the patch, try using EQ
to trim off excess bass or high end. The EQ'd patch might sound odd in
isolation, but it may well fit the track better. Another tip for those
reluctant to get into heavy editing is to layer patches to get the desired
result. For example, a deep bass sound mixed with a more percussive patch might
help you produce a bass that you can hear as well as feel. It's important not
to over-orchestrate your arrangements, especially when you have fat synth pads
and overdriven guitars occurring at the same time. The same is true of some
treated drum loops, which can actually take up a lot of space. If in doubt,
listen to some commercial mixes in a similar style to the track you're working
with. You may be surprised at how little there is going on at any one time."One
of the questions we hear most from Sound On Sound readers is 'Why doesn't my
music sound as 'produced' as the music I hear on commercial CDs?'" It may
help if you get your sounds as close as possible to correct at source so you
don't need to use a lot of EQ. Few budget mixers have the kind of EQ that works
well when called upon to make major tonal changes, and often you'll find that
the more you EQ, the harsher, boomier or less focused your mix becomes.
Reduced Reverb Once you've
created space in your mix, don't give it all away by filling every available
gap with heavy reverb. As it happens, reverb is one area where a decent-quality
unit really helps, especially if you use a lot of small-room or ambient
reverbs. You don't have to spend a fortune: the excellent Lexicon MPX100 costs
around £200, yet still offers the general feel of Lexicon's more expensive
studio processors. Bear in mind that heavy reverb tends to push a sound to the
back of a mix, so if you want a vocal to appear up-front you should use a
fairly bright reverb, with 80mS or so of pre-delay. Don't overdo the decay
time, either, especially with up-tempo songs. Other effects should also be used
carefully -- use an effect because the track needs it, not because you happen
to have it! Dramatic effects can be made even more dramatic if you use them for
short sections of a song rather than having them full-on all the way through,
and delay effects often work best when the delay time is related to the tempo
of the song.
Master The Situation What
many people don't realise is just how great a difference is made to commercial
records at the mastering stage. Prior to mastering, you might be surprised at
just how ordinary some mixes sound. Mastering often involves nothing more than
compression, limiting and equalisation, but it has a dispro ----- Favourite
Strings Guitars and basses can be a dead giveaway that a recording is not a
commercial one if they are poorly recorded. Sticking a mic in front of an amp
is probably still the best way to get a live-sounding recording of a
performance, but if this is not feasible there are so many good recording
preamps around now that there's little excuse for getting a thin or buzzy
guitar sound. However, go easy on the overdrive, and consider using less
overdrive but combining it with compression if you need sustain. Use a gate to
keep your guitar tracks clear of unwanted noise, and also try to reduce clutter
in the arrangement: where two guitars are playing essentially the same chords,
for example, first decide whether both guitars are actually necessary. If they
are, consider using different chord inversions for one of the parts, or even a
capo. Incidentally, acoustic guitars almost always sound better miked than
DI'd. Basses can actually be more difficult to record than guitars, because
although they may sound great in isolation when DI'd via an active DI box and a
compressor, they can still lack punch in the context of the overall mix. Again,
consider miking the amp or using a guitar DI preamp so you can add just a
little overdrive to warm up the sound. Compression will help keep the sound
even and punchy. A good tip here is to make any necessary EQ adjustments when
the rest of the track is playing, because then you'll be able to make the sound
match the track. If you EQ the sound first it might sound great on its own, but
could get completely lost when the other faders are brought up. ---portionate
effect because of the quality of the equipment being used and the expertise of
the person using it. Yes, this is one area where the equipment does make a huge
difference, though with all-in-one mastering processors now available at prices
project studio owners can afford, it is possible to get a professional sound at
home providing you have good ears and accurate monitors. A good equaliser
doesn't just change the spectral balance of a sound: it also seems to lift
information out of a mix. One popular mastering technique is to apply an
overall boost of just one or two dBs at around 15kHz with a wide bandwidth
setting. This is what people mean when they talk about 'air EQ', 'sheen' or
'gloss'. With a nice equaliser this boost will lift out high-end detail while
at the same time pulling the vocals forward, but it shouldn't make the sound
harsh or toppy. Similarly, adding a gentle dip at around 180-250Hz may help
clarify a muddy lower mid-range, while a boost at 70-90Hz will firm up a weak
bass end. It is vital to use a classy equaliser for this job, though -- a cheap
one just won't deliver the necessary fairy dust! (And a good mastering
equaliser probably costs more than many people's entire computer-based
recording system.) I use an SPL Vitalizer on some of my mixes, as it replicates
many of the EQ functions of a mastering processor, and if you don't have the
money to buy a high-end equaliser I'd recommend one of the lower-cost versions
of the Vitalizer as an easy-to-use alternative. A very gentle overall
compression of around 1.1:1 with a threshold of -30 to -40dB will make a mix
sound more even and more powerful. However, multi-band mastering processors add
a lot of flexibility in the area of compression, because they give you the
opportunity to perform operations such as applying more compression to the bass
end than to the rest of the mix. This helps firm up the bass end only, and any
spectral imbalance caused by the different compression ratios can be restored
by adjusting the levels of the various frequency bands at the compressor's
output. Mastering also tends to involve limiting, a process similar to
compression (but with an infinitely high ratio) that controls just the tips of
loud peaks. Applying a little limiting will often make it possible to increase
the avera"The secret of a produced sound starts with the source material.
It doesn't matter what you do to your recording afterwards if this isn't up to
scratch." ge level of a mix by several dBs without any side effects
becoming audible. If you're starting from a 20- or 24-bit master and you reduce
to 16-bit right at the end of the process, this has the benefit of using the
whole of the bit resolution of the CD format, which means less noise, less
distortion and better low-level resolution. It also makes your CD sound as loud
as the 'produced' commercial CDs in your collection. Use a limiter specifically
designed for mastering (such as the Waves L1 plug-in or the limiter in your
mastering processor) and don't over-limit, or you will start to hear the
difference. Usually 4-5dB of limiting is all that's needed. A note on limiting:
Any decision taken to limit or not to limit is a musical one. Some musical
styles apply heavy limiting as part of the musical style's "sound", others don't.
Production requirements may suggest limiting is needed, for example preparing
your music for broadcast might necessitate limiting in order to compensate for
the radio's smaller dynamic range. In our example we exaggerated in our
limiting setting - The student should understand that limiting to produce a
5.2dB attenuation is a bit heavy. Normally we should watch out for a maximum of
4dB attenuation. Processing via tube or simulated tube circuitry can also warm
up a mix (which is why tube EQs and compressors are popular for mastering), but
again you get even more flexibility if this tube processing comes as part of a
multi-band package. For example, adding a little gentle tube saturation only to
the low band will noticeably thicken the bass and kick drum without spilling
over into the midrange and high end. Similarly, adding high-end saturation has
an effect similar to an enhancer, enhancing detail and and lending gloss. The
secret with all these treatments is to use them sparingly and always compare
the processed sound with the unprocessed to make sure you have not gone too
far. A good processor will transform a recording with just a dB or two of adjustment
where needed. If you find you're using a lot of processing, suspect your basic
mix of being too wide of the mark.
Summing Up As you can see,
the magic of musical production isn't something you 'paint' on at some point in
the recording process, but is rather the result of attention to detail at all
points throughout the recording, starting with the musical arrangement and choice
of sounds. Nevertheless, processing at the mastering stage (ie. after your mix)
can make a huge difference. Professional mastering is expensive for a reason:
pro mastering engineers have great equipment and a lot of experience in using
it. If you're not confident you have the necessary equipment and expertise to
do your mix justice, think about getting your work professionally mastered,
especially if it's destined for commercial release. If you're going to do this,
don't do any processing at all on your final mixes -- leave each track just as
it is. On the other hand, if your mix is 95 percent there and you don't have
the budget for pro mastering, don't be deterred from doing the job yourself, as
there are now several hardware mastering processors (as well as innumerable
software plug-ins) within the reach of serious project studio owners, and these
can really help to get the job done.
MIXING IT by Paul White mixing
methods & approaches
Although there are no hard and fast rules in mixing, PAUL WHITE provides some
handy guidelines and ways for you to approach your own mix. It is fascinating
to see how music mixing has changed over the past two or three decades. In the
Sixties, arguably the heyday of pop, the sound of a record came almost entirely
from the performance of the musicians -- the mixing engineer's role was largely
concerned with setting up an acceptable musical balance and adding a touch of
plate reverb where needed. Today, music production is all too often less about
musicians performing together and more about assembling a composition in
pieces, rather like a jigsaw puzzle, where those involved are not entirely sure
of what the picture is supposed to be until the puzzle is finished. Then, of
course, there's the use of pre-recorded material to consider, whether it be
snatches from a previous recording, samples of live musicians playing rhythm
patterns or riffs, or 'found' sounds from TV and radio to add atmosphere and
effects. Due to the creative nature of contemporary music production, today's
mix engineer must be every bit as much an artiste as the musicians on the other
side of the control room glass. So, is there any common ground with the mix
engineer of the Sixties and Seventies? Regardless of the style of music, or
whether the sounds are samples or recorded performances, the mix engineer still
has to balance the various parts, handle the stereo positioning of sounds
within the mix, equalise and apply effects where necessary. In professional
circles there's invariably a producer looking over the engineer's shoulder who
calls the shots, but most SOS readers double up as engineer and producer, and
quite often as the artiste too -- which means knowing something about music
production as well as engineering. So how do you set about turning a good
recording session into a good master tape? Here are a few mixing guidelines for
you to follow...
APPROACHING THE MIX Once the
recording stops, and ideally after a suitable break, the mixing session starts.
At this point you should have track sheets describing what's on the various
tape tracks, any notes taken during the recording (MIDI instrument settings),
and all the mixer EQ, level and routing controls set to 'neutral' ready for a
clean start. The only exception to this latter condition is if you've been
setting up your mix as you were recording, in which case it's simply a matter
of checking that nothing is routed that shouldn't be. It helps to separate
logical groups of sounds into subgroups, so that the mix can be handled with
fewer faders. This is particularly helpful if you don't have the benefit of mix
automation. For example, if the recording includes real drums, these are likely
to occupy several tracks so it makes sense to assign them to a single, stereo
subgroup. Other candidates for subgrouping are backing vocals and multi-layered
keyboard parts. Unless the quality of the original recording leaves something
to be desired, it should be possible to set up a workable balance fairly
quickly, without resorting to EQ. Effects can be added later, but it helps to
have the necessary effects units patched in and ready, especially reverb which
will probably need to be added first. In order to keep the sound quality as
high as possible, de-route any mixer channels that aren't being used, turn down
their aux sends, and mute any monitors that aren't being used during the mix.
Also check the gain setting of any effects you have patched into the mix, so
that their input level meters read a healthy signal level on signal peaks. The
loudest channel aux sends should be set to between three-quarters and full up,
and the input gain control of the effects unit adjusted accordingly. If it is
possible to route unused sends to an aux bus that isn't being used, this can
reduce mix noise considerably, and any effect needed only on a single channel
will be quietest if connected via the channel insert point rather than via the
aux send system. If mixer noise is a problem, it can sometimes help to patch a
gate between the console's effects send outputs and the effects unit inputs.
GETTING THE BALANCE A good
mix starts with a solid foundation, so it pays to sort out the rhythm section
first, but don't spend too much time on things like the type and level of
reverb on these instruments, because this will sound very different once all
the other instruments are in the mix. Once the rhythm section is working, then
add in the lead vocal followed by the other parts of the mix, always being
aware that you must leave space for the vocal. Up to this point, it can help if
all your sounds are panned to the centre of the mix -- if you can get the mix
sounding good in mono, it'll invariably sound even better in stereo. It's only
when I've reached this stage that I start to worry about EQ, but I know other
engineers who simply push all the faders up and try to sort everything out at
once. There's no right or wrong way as long as it works for you, but if you
don't have a lot of mixing experience, I think you'll find my approach less
stressful. Try not to monitor too loudly, as this will affect your judgement
and may eventually damage your hearing. The most logical monitoring level to
use would be at the same level as the end user is likely to listen at -- in
other words, a sensible domestic listening volume.
STEREO IMAGE Once the balance
is working in mono, and maybe you've added a little vocal and drum reverb, you
can concentrate on refining the effects, the EQ settings, and the stereo pan
positions. Traditionally, all the 'heavy guns' go in the middle of the stereo
soundstage, by which I mean kick drums, bass guitars and bass synths. Aside
from the fact that very low frequencies don't really benefit from panning, it
helps if you distribute high energy bass and percussion sounds equally between
the two speakers. Lead vocals also tend to be panned to the middle, not for any
technical reason but purely because we expect a singer to be centre-stage. I
invariably add some compression to vocals while mixing, simply to even out the
level, and if noise is in any way a problem, then I'll also gate the vocals
before the compressor. A useful compressor setting is to choose a fast attack
combined with a release time of 0.5s or so and a ratio of between 4:1 and 12:1,
depending on whether you want to hear the compressor working or not. Backing
vocals, on the other hand, can go wherever you want to place them, and you
might want to compress the overall backing vocal mix. If this is in stereo,
don't forget to use the compressor set to its stereo link mode. I like to hear
different backing vocals coming in from different sides, but it's your song --
so put them where you like! If you're experiencing sibilance problems on your
vocals, try a less bright reverb setting or try adding a little EQ cut at
around 6kHz. If the problem persists (which it shouldn't do if you were paying
attention at the recording stage!), you may need to bring in a de-esser. Having
said that, I've never yet used one on a serious recording, as I feel they
compromise the vocal sound to too great an extent. When the mix finally starts
to happen, it helps to take a break, have a cup of tea, listen to a few
records, and then come back to it. I find it invaluable to listen to the mix
from the next room, with the adjoining door left open, as even the slightest
balance problems become very obvious. I mention this technique at regular
intervals, because of all the tricks I've learned over the years, this is one
of the most helpful.
GAIN RIDING On most mixes
you'll need to do a little gain riding to sort out awkward vocal levels that
the compressor can't handle, or to bring solos in and out, but again, listening
from next door can help you identify the areas that need manual attention and
those that can be left alone. One general rule is not to mess with the rhythm
section level once it's set up, as this would run the risk of upsetting both
the overall balance and the continuity of the song. If there are several level
changes to handle during a mix and you think you might run out of hands, then
rope in the musicians to help, but always put wax pencil marks on the desk for
them to follow, otherwise you might find the balance changing with every pass!
"A good mix starts with a solid
foundation, so it pays to sort out the rhythm section first."
If a track requires a fade-out ending, make sure you start to fade at least 20
seconds before the recorded material runs out, and don't rush the tail end of
the fade or it will sound unnatural. If the album is going to be compiled on a
hard disk editing system, such as Sound Tools, don't bother with the fade when
mixing but do it as part of the editing process; this will be smoother and will
fade into true silence.
SALVAGE TECHNIQUES In a
perfect world, every tape track would contain a perfect performance at exactly
the right level with no noise or unwanted sound to be heard -- but life is
rarely like that. Apart from some degree of tape and circuit hiss, and maybe
the odd dB of hum, there are always extraneous sounds such as breath noise or
digital synth grunge to consider. Gates are very effective in cleaning up noisy
tracks, but care must be taken to match the release time of the gate to the
natural decay envelope of the sound being treated. However, gates can only keep
the noise down during pauses, they can do nothing when a signal is present. It
stands to reason, therefore, that if you decide to gate a whole mix, the only
real benefit will be a clean start and a clean end. If your mixer has MIDI
muting, this can be set up to kill any channels when they are not in use, thus
reducing the level of cumulative noise build-up in the mix. It is necessary to
go through each tape track and set up the mute points individually, and if you
can arrange muting and unmuting to occur on a beat, it will help to disguise
any sudden change in background noise level. While gates can only clean up
pauses, dynamic noise filters can actually remove noise in the presence of
signal, though you have to take care that they don't introduce audible
side-effects. Dynamic filter units simply filter out the higher frequencies
when the signal level is low, and though they have no audible effects when the
treated signal is strong, they do tend to affect the tail end of long reverbs.
For this reason, it helps to route the reverb via one subgroup and the channels
to be de-noised via another, so that the reverb escapes treatment.
FIXING THE MIX Occasionally
you'll end up with a mix which still needs that extra something, especially if
you're working on a tape recorded by someone with different ideas to yourself
when it comes to what things should sound like. Compressing a complete mix will
reduce the dynamic range and increase the average energy of a mix, but as
contrast is a necessary part of music, you might find the mix gains in one area
and loses in another. The attack time of the compressor may be increased to
20ms or so to allow transient sounds to cut through, though the type of
compressor used can make a huge difference to the subjective outcome. Soft-knee
compressors produce the most unobtrusive results, but the other side of the
coin is that an obviously compressed mix can also sound quite exciting and
vibrant, which is why certain vintage valve compressors are so popular. If your
mix is correct in the first place, why should it need any further EQ? I can't
provide the complete answer, but I do know that some equalisers are capable of
flattering even the very best mixes. Music can be made to sound 'louder' by
gently cutting the mid-range slightly, and it's quite common to treat a whole
mix with an exciter or a dynamic equaliser to add sparkle and detail. Since
buying my SPL Vitalizer, I invariably use it when mixing and there's simply no
way to simulate the effects using conventional EQ.
LISTEN WITHOUT PREJUDICE
Before finally approving your mix, make sure you listen to it on as many
different stereo systems as possible, including the car, otherwise you run the
risk of creating a mix which sounds good only in your control room. And if you
have to ignore all my suggestions in order to get your mix sounding the way you
want it, that's fine too -- there are no hard and fast rules and the end always
justifies the means! Have fun.
MIXING TIPS Occasionally you
get a mix that just won't sound right, often because the song hasn't been
arranged well enough to leave space for all the important parts. If you come up
against one of these, here are a few tips you can try. By working through the
following points, you should at least end up with something usable.
Set up a rough mix, in mono, without using EQ or effects and then work from there. Also check that the mix sounds OK in mono.
If the mix seems too busy, ask yourself if all the recorded parts are really necessary or can you lose something (try muting each part and see what impact that has). What matters most in the majority of pop songs is the rhythm and the vocals, the rest is decoration. If you can't lose something completely, try mixing it so low that you only notice it if you turn it off.
If the mid-range sounds are fighting with the bass sounds, try using EQ to 'thin out' some of the sounds. Take some bottom end out of the pad synth, backing vocals or acoustic guitar parts.
Still no joy? Then go back to the basic rhythm section plus vocals and see if that is working. If not, is it too late to try a different drum or bass sound? Similarly, if you're working with a sequencer, you could try picking thinner pad keyboard sounds or brighter bass sounds.
Don't overdo effects -- reverb creates the illusion of distance and space in a mix, both of which are the opposite of 'up front' and 'in yer face'. As the eskimo said when burning his canoe to keep warm, "You can't have your kayak and heat it!"
If things are looking up, try panning the instruments and effects to their desired positions -- this will help improve the separation between individual sounds and enhance overall clarity.
Though exciters shouldn't be thought of as a means to salvage poor recordings, the extra separation they create can make the difference between a so-so mix and a good one. Use as a last resort only when you've got everything as good as it can be.
Perhaps the mix sounds fine but just lacks cohesion or punch. In that case, try a little overall compression. A soft-knee compressor will usually provide the most transparent results, but try whatever you have and let your ears be the judge.
USING REVERB Digital reverbs
create the illusion of stereo by synthesizing different sets of delay taps for
the left and right channels, which makes the reverb patterns slightly different
between the left and right outputs. This makes it possible for us to take a mono
tape track and give it both a stereo identity and a sense of being somewhere,
rather than existing in a void. Even if no obvious reverb is needed, a sound
can still be given substance and width by adding a very short reverb, ambience
or early reflections pattern to it. For drums and vocals, where a longer reverb
time is often chosen for artistic reasons, try to pick a setting that doesn't
fill up all the space and stifle the mix; it may help to add a pre-delay of
around 50ms or so. If the reverb makes the mix sound muddy, feed the reverb
back through a channel that has EQ and roll off some of the bottom end.
Alternatively, if the reverb is diluting the stereo image of a sound too much,
try panning the instrument sound and its associated reverb to exactly the same
point in the mix. This will kill the stereo width effect, but can be effective
where a sound needs to emanate from a precise location. Avoid putting more than
the barest hint of reverb on bass drums or bass instruments (unless for
deliberate effect) unless the mix has loads of empty space to allow the reverb
to breath, without clouding the overall picture.
USING DELAY Try panning an
instrument (eg. guitar) to one side of the mix with a delayed version (from 5
to 50ms) panned to the other side. The sound will appear to be coming from the
speaker that's carrying the unprocessed (dry) sound, even if the delay is as
loud as the original signal. The psychoacoustic reasons why this is so are
rather too complex to go into here, but this does provide another way to add
space to a sound. If the delay is then modulated to produce a chorus sound, the
result is to create the illusion of movement, and when listening in stereo you
really can't tell that one channel is carrying a dry sound and the other a
processed version -- the movement seems to occupy the whole of the space
between the speakers. Delay can be used to create more conventional echo and
doubling effects, of course, and it has become fashionable to set up
synchronised delay times that are a multiple of the tempo of the song. For
example, if a song is running at 120bpm, each beat is 60 divided by two seconds
long -- which is half a second. Therefore, a delay of 500ms (half a second),
250ms, or 125ms will always create echoes that are in sync with the music. You
can also divide the beat time into threes to create echoes that occur in
triplet time. Clever use of delays can help add drive and push to a song (check
out The Edge's guitar playing on most U2 tracks).
CREATIVE EQ EQ is complex
enough to warrant a complete article in its own right, though I subscribe to
the school of thought that recommends leaving it alone unless desperately
needed, and even then using as little as possible. Using EQ to cut rather than
boost, where possible, invariably results in a more natural sound. For general
brightening of a track, try either a subtle amount of boost at 6kHz or a hint
of high shelving boost (usually 10-12kHz on most desks). EQ can be used to
create separation in a crowded mix by using it to narrow the area of the
spectrum occupied by a particular instrument or voice. Most sounds have the
bulk of their energy in one section of the audio spectrum, but there will also
be small amounts of high and low frequency energy outside this band. By using
high and low EQ cut to 'trim' away these extremes, it may be possible to make a
sound sit more comfortably in the mix. Even though such EQ'd tracks may sound a
touch unnatural in isolation, they may still work well once in context.
Electric guitars often benefit from this kind of 'spectral trimming' as do
acoustic guitars (to take out some bass end), some drum sounds, and backing
vocals. Acoustic instruments are best treated gently with maybe just a little
LF cut. Lead vocals, or vocals that are very exposed in the mix, should be
treated most cautiously of all. It's invariably better to get the right vocal
sound at the outset, by choosing a sympathetic mic, rather than by using EQ
later.
The perfect mix There are many ways to get
your songs to final form. Lets assume, for this article, final form means a
beautifully polished piece of music in 16 bit 44.1 khz digital audio (i.e., the
"red book" cd audio standard) or a standard wave file. You need to
start, of course, with a fully or almost finished song. This is the point where
the writing ends and the TweakMeistering begins. I'm going to give you some
hard earned tips on Mixing and Mastering. Mixdown and Mastering, traditionally
speaking, are two very separate processes. Mixdown is the art of leveling,
equalizing and effecting all the various sources from many tracks down to a
stereo Mix. Mastering is the process of taking the stereo mix and putting it in
the final album-ready form. Recent software and hardware developments make
these processes easier and less expensive than they ever have been in the
history of making music. Given that much of the time we can stay in the digital
domain we can add processing to our heart's content and maintain a high signal
to noise ratio and achieve optimum dynamics for the piece at hand. TweakHeadz "Overall" Power Mix
Parameters Please consider these parameters not as rules but a starting
point for you mixes for the standard pop song or ballad. Of course the
instruments change if you are doing techno or symphonies, or ambient stuff, but
the reference may still be helpful. Match the following instruments when soloed
in place to the db markers on your mixing desk or your mixdown deck or
software. Set the trims:
Solo each instrument in succession and set the trim so the signal peaks a 0db. Kick drum 0db +3 eq at 50 Hz +1 db at
3khz -3db 275 hz No FX except maybe subtle ambience. You will tweak the kick
again, this is just to get you going. Snare
-2 db eq to taste in the frequencies above 4khz. Add reverb if the song calls
for it. Do the best you can to keep it out of the way of the vocal, even if you
have to pan it a few degrees. Lead Vocal
0db use a low cut filter to eliminate rumble and plosive pops around 100-200
hz. Carefully enhance the delicate high end around 15khz to add air and sheen
and don't overdo it! This is the trickiest adjustment and may often spell hit
or dud. Perfectly center the vocal and pan it not with pan controls, but with
very subtle left/right hi freq eq's. Put on the cans (headphones) and make sure
its in the absolute center of your forehead.. Every word must be intelligible.
Add reverb and delays but don't let it get smeared. Cymbals -25 db Avoid letting these get in the way of the vocals.
Pan them to 2 o'clock and remember their main function is to add the glue to a
track to hold the music together--they do not have to be loud or present Synth pads -20 db Do these in stereo
and hard pan left and right with generous effects if needed. However, keep them
in the back. Pads indeed are beautiful additions to a song but don't let them
overshadow any of the main elements of the song. Bass -10 db Always front and center. If you use FX restrict
yourself to chorusing or a light flange--no reverb. Rhythm guitar -15 db pan off center eq: use a low cut filter to get
rid of any bass and add a mid range eq for a slight narrow boost, but make sure
it is not competing with the vocalist's sweet spot. Percussion -20db- put these elements off center unless they are
essential to to basic beat. EQ in a tasteful way if necessary. Watch the meters
when you play the whole mix through the board. You should have peaks at +3db.
If what you have is more notch down every fader in 1 db increments until you
get there.
Mono Check:
Always check you mix in Mono and look for sudden drop outs or instruments that
disappear. That's phase cancellation at work, and it happens with stereo tracks
and effects. No faders above 0db
rule:
When getting a mix started follow this religiously. If you find your vocal
doesn't sound good unless its at +5db then move everything down 5 db. Conserve
headroom. You don't want your mix compromised by that awful crackle at the peak
of your song. Now you fine tune to taste. Listen for the quality to
"lock". A great mix of a great song will fill you with absolute
elation. You'll be blown away and in awe. You will feel in love with it. No
kidding. Might sound corny to the less mature among us, but I assure you its
true. A great artist friend of mine puts it this way. Greatness in art depends
solely on how much love you put in to a work. You put it in, it pays you back,
your friends back, and everyone who listens. Moral of this lesson. Never take
mixing and mastering lightly. The tiniest fader movements make a difference. Be
exacting!
The Mix is a Dynamic, Moving Process
Don't just sit there while your mix goes to tape, or disc, or DAT. If you are
using a board, assign the faders to subgroups. For example, if you have 4
subgroups you might want to send your vocal tracks to groups 1 and 2 and
everything else to 3 and 4. This way you can slightly alter the balance between
the vocalists and the band as the piece goes to tape. This technique, while
tricky, can yield outstanding results. You can give the vocalist a touch more
edge just when they need that ooomph and when the vocalist takes a break you
can subtly boost the band a bit. If you have 8 busses you might dedicate 5 and
6 just to drums and 7 and 8 just to effects, nudging each as is appropriate.
The Role of Compression at Mixdown
On it's way to the recording device, you can patch a compressor/ limiter/gate.
The Gate simply cuts out any audio below a certain threshold so that any hiss
or noise coming from your synths or mixer is eliminated before the music
starts. The limiter keeps your peaks under a certain fixed level and will not
let them go higher. A Compressor is a volume slope applied to the audio
material goin through it. It can amplify the "valleys" and attenuate
the "peaks". Essentially compression reduces the dynamic range we
have just struggle to achieve in our mix. You might wonder why you would want
that. In many circumstances, you don't want it. However, in the majority of
cases you will find it useful, especially if you want your music to be
"hot", "have punch" "be as loud as possible", or
have the consistency of a radio mix. The stereo compressor also helps balance
the song and give it a uniform character we are so used to hearing in
commercial music. It essentially gives you the strongest and smoothest mix and
calms down some of the 'jaggged edges' that might disturb the casual listener.
However, it is also very easy to make a mix totally lifeless with a compressor
and reduce its dynamic power. What started as a powerful orchestral arrangement
can end up a wimpy piece of Mall Muzak so be careful and bypass it frequently
to make sure you like what you are tweaking up. I think compression works best
to attenuate that occasional peak that rips through the roof of a digital audio
recorder and ruins the track.
The Role of the Mastering processor
Mastering processors are becoming more popular these days. The TweakMeister
likes them. I have noted over and over how the effective use of a mastering
processor can transform a good mix into a great master recording. If you have
one, you might consider using that in lieu of a compressor at mixdown as
mastering processors usually have all the functions and additional functions
such as mastering eq, multi-band compression (that is adjustable compression
for the bass, mids and highs) as well as limiters and gates. These mastering
tools can go a long way to giving your music a unique sonic imprint. There are
many uses. In addition to adding the refining touch to your mix as it goes to
the recorder, it can be used to give all your songs on an album a consistent
uniform character and balance the volume between widely different songs giving
your project a professional touch. Using narrow band mid range eqs can give you
a very contemporary sounding presence and make your dance tracks come alive
with freshness. Pumping the compressor a little at 50-60hz can give you the
"kick in the chest" kik drum without wrecking the delicate dynamics
of the high end vocals. There are many more applications such as using them to
send midi tracks to your digital audio mixer compressed optimally, ducking for
voice overs, de-essing, warming through "tape saturation" parameters
and Hard Gate effects on individual tracks. Remember Tweakheadz rule of thumb:
Any piece of gear can be used in any way as long as it enhances the quality of
the final product.
Software Mastering and
Post-Production A good digital audio sequencer will let you master in
the digital domain of your computer. Some softwares that I think are of
particular merit for mastering are Logic, Cubase, Sound Forge and Vegas. I'm
just going to look at Vegas here, because I am enamored with it right now. The
main thing is to be able to draw a volume envelope over the whole waveform.
Rather than botch a fade 20 times on an analog mixer, simply draw in the
perfect fade with the mouse. Where the piece loses intensity, notch it up a
tad, to restore your intended dynamism to your mix. Say you have the perfect
mix except for one horrible "sp-p-p-lat" where your sequencer choked
at bar 72. No prob. Just remix the offending bar again, cut out that piece in
Vegas and drop in the new one and let the automatic crossfading give you the
absolutely perfect, digitally calculated crossfaded splice. Works! Need to
touch up the EQ and do your compression in software? Tweak it in. It's all
undoable, so your not going to ruin anything. Decided the mix you did last year
really sux? You need to cut out a chorus or fade 5 seconds earlier? Say you did
a trance piece but the kick is so wimp that it makes you cringe? Just drag in a
looped 808 kik and paint it on the next track, setting the volume and
compression to make the whole song whupass. :) Vegas gives you the tools. In
fact, I like it better for post pro than as a multi track.
Summing Up: Whether you are
writing industrial hardcore or the darkest ambient, a 100 piece orchestra or a
stark minimalist a capella mix, always keep your ears tuned to making an
artistic statement, a work of unforgettable beauty. This is the bottom line.
The more control your Mixer gives you, the better you can paint the overall
image. Working with compressors and mastering processors gives you a shot a
polishing that image much like we polish a stone to bring out its colors. Hope
this article helped you get a handle on the concepts of the perfect Mix,
mastering and post-production All the Best! Rich the TweakMeister
WHAT THE HELL is MIXING?
by Nigel Lord
Even so, the general principles of mixing hold good. Before we look at these
principles, a word about the basic requirements. Firstly, your ears. Keep them
fresh (and clean, of course). Never ever attempt to mix a piece of music at the
end of a long listening session. Take a break of at least an hour and preferably
overnight. The human ear is incredibly good at identifying problems with
certain sounds, but not if it's had time to get used to them. Secondly, your
monitoring system. It goes without saying that you should buy the best
equipment you can afford. Without a reasonable system you'll have no idea how
accurate an image of the music you're getting. But even if you do splash out on
an amp and speakers, how do know you're getting a true picture? The answer lies
in listening to your mixes on as many other systems as possible, so that you
know, for example, if you're tending to mix a little bass-heavy or aren't
adding sufficient top end. Finally, don't think about mixing through
headphones. Irrespective of what it may say on the box, headphones do not reproduce
music in stereo. They reproduce it 'binaurally', which is quite different, and
makes it all but impossible to set up an accurate stereo mix.
FEEL YOUR WAY You can take
any approach to mixing you feel is appropriate to your music, from the 'wall of
sound' (favoured by people as disparate as Phil Spector and hardcore guitar
bands), to a cleaner, more considered approach where space is created around
each instrument in terms of both frequency and time. The latter approach is
undoubtedly the more time consuming. You need a good ear to determine the area
of the frequency spectrum in which each sound predominates and to prevent too
much overlap. But that's what professional studio engineers and producers are
able to do, and the results usually speak for themselves. The most basic
function of mixing - the balancing of levels between individual instruments (or
tracks) - is not something anyone can advise you about. You know how you want
your music to sound and the level controls are in your hands. But do bear in
mind the likely destination for a particular mix. There's no mystery here. The
primary requisite for the dance floor is a rhythm track which to hit the
punters in the solar plexus. But apply the same bottom end to a song destined
for someone's car stereo, and it'll cause major problems. Bass needs to be
tailored quite specifically to the needs of a particular track. Using EQ, it's
possible to strip away low frequencies to quite a high level before the ear
will tell you anything is missing (though this is where having an accurate
monitoring system is so important). Very low frequencies are often not audible
but will soak up a high proportion of a speaker's available energy. Filtering
them out can actually increase the perceived volume of the audible bass and
will certainly reduce distortion at high sound pressure levels. As effective as
EQ is in such applications, it can be something of a mixed blessing in the
wrong hands. Use it to correct minor problems with individual sounds and to
create space round certain instruments by filtering out unwanted frequencies,
but don't rely on it as a universal panacea. Obviously, much will depend on the
versatility of the controls; sweep and para-metric EQ is much more effective at
homing in on problem areas of the frequency spectrum. But they can just as
easily be responsible for raising the profile of certain sounds till they just
don't fit in any more. There's no clear dividing line between the two, except
to say that the ear is much more forgiving of frequencies which aren't there
than those that are. So wherever possible, try cutting the frequencies you
don't want, rather than boosting those you do.
WET, WET, WHAT? One of the
areas of controversy which has divided musicians and producers for years is
whether to record tracks 'dry' or 'wet'. No, it's nothing to do with towelling
yourself off after you get out of the bath, it's down to whether you add
effects such as reverb and delay before you record them or whether you leave
them dry and add your effects during the mixing process. There are pros and
cons to either approach which need to be carefully considered. Record your
track with effects and they're impossible to remove subsequently. If at the
mixing stage, you decide you have too much reverb on the vocals, you'll have to
live with it, or re-record the performance. On the other hand, you may only
have a single effects processor and want to use this for another effect on
mixdown. So unless you do without the vocal reverb, you have no choice but to
record with it. Vocals need reverb like England needs Michael Owen but overdo
it and it's dead easy to lose the voice in a sea of mush. Reverb often has the
effect of pushing vocals back in a mix. Great for preventing them sounding like
they're sitting on top of it (as they often can when recorded dry) but not so
good if it's masking an otherwise excellent performance. You can get round this
by introducing a pre-delay to the reverb. This can be set up on most effects
processors and can be applied to many instruments, but is particularly useful
for creating space around a vocal or bringing it forward while giving it an
'aura' of reverb. You'll need to experiment with the pre-delay setting, but
around 30-50ms should do. The tendency of reverb to clutter up a mix is
something you need to listen for very carefully. And it's vitally important
that you choose a program with the right reverb time for each track. 'Hall'
programs sound great in isolation but can clog up the music quicker than the
mud at Glastonbury. Short reverbs are great for creating interesting room
ambiences and don't take up as much space in the mix, but can sound unnatural.
This is one argument for not adding reverb until mixdown. When all your
instruments are 'in place' you can properly assess the type and quantity of
reverb you'll need. If this isn't feasible (perhaps you only have one effects
processor) try to keep reverb to the minimum needed to achieve the desired
effect and limit reverb times. Long reverbs often don't have time to subside
before being retriggered and can accumulate in your mix like Glastonbury mud
(yes I know I've said it already, but you should have seen it). Use pre-delays
if they're available and don't reject the use of gated programs. The overuse of
gating effects on drum sounds in the late 80s may have contributed to their
current unpopularity, but they can be extremely useful in chopping of
unnecessary reverb tails and creating space. Another trick is to limit the
frequency response of reverb using either your mixer's controls, or your processor's
built-in EQ (if it has it). This is best done by monitoring return signals from
your reverb unit and cutting any unwanted frequencies or limiting those which
appear to be obscuring the sound.
PANNING FOR GOLD The art of
panning instruments and sounds to create a convincing stereo image is one of
the most important in mixing, yet is frequently misunderstood. So often, you
hear demo tapes where the instrument placing appears to have been carried out
quite arbitrarily. It's like sharing sweets: one for this side, one for that
side, and one in the middle for luck. Panning is an essential part of mixing; a
means of achieving balance in your music as well as creating the transparency
of a stereo image that we all take for granted in commercial recordings, but
which can be difficult to reproduce. Though I'm loathe to talk about what
usually happens in a mix (if we all did what 'usually happens', we'd still be
playing whistles and banging hollow logs), there are a few basic ground rules
which you really can't get away from. The first is that the dominant,
low-frequency instruments invariably sound better placed at or around the
centre of the mix. I'm talking here about the bass drum, the bass guitar or
synth and any deep percussive instruments you may be using. Pan them too far
left or right and your music will sound off-centre. Fine, if that's what you're
aiming at, but there are much better ways of getting creative with your pan
controls. One of the best is to set up some interesting rhythmic interplay using
your different percussion sounds. Obviously, if you're using a sample loop for
the drum track this may not be possible, but you could always augment it with
additional percussion (such as cabasa or claves) and pan these to the left and
right. Alternatively, try setting up a delay on one of your instruments and
panning the dry and delayed signals to opposite sides of the mix. Lead vocals
are also placed at the centre of mix in most recordings, though this has much
to do with where you'd find the singer at a live performance. There's is
certainly nothing to prevent you experimenting with the positioning of the
vocals, particularly where you also have backing vocals as well which can be
placed in a similar position on the opposite side to the lead vocals, to balance
things out But again, hard panning left or right of any vocal parts can be
difficult to live with. I should also remind you that pan controls are not
static, and there's nothing to prevent you from panning instruments left and
right during a recording. It's easily overdone, but in moderation it can
provide a real sense of movement (quite literally) within a mix. A more subtle
alternative would be to use a stereo chorus program on a effects unit which
features auto-panning. This leaves the dry signal in place, but shifts the
chorusing between the left and right speakers. And talking of effects brings us
back to reverb which can be used to create a convincing stereo image from any
mono source. By panning outputs left and right, you can use reverb to produce a
much broader, more expansive sound, even at short reverb times. On the other
hand, reverb may be upsetting your stereo imaging by changing the apparent
location of a specific instrument. If this does occur, try panning the reverb
to exactly the same point in the stereo field as the dry signal, preferably
sticking to a mono effect.
INSTANT MIX FIXES To round
things off, how about a couple of ways to provide an instant fix for your mix?
If you've already mixed down to stereo and found the result disappointing, try
sticking the entire mix through an aural enhancer. Though not always successful
in treating a complete mix, they can alter the overall sound in subtle and
distinctive ways, particularly processors which affect the stereo imaging.
Alternatively, give the track to someone else to mix. The results may not be to
your liking (at first), but I guarantee they'll reveal a side to your music
that wouldn't have emerged had you been sat behind the mixing desk. What have
you got to lose?
TIPS ON... Recording Vocals
If you've got a storming vocal on tape you're halfway towards a great
production. PAUL WHITE offers some tips on perfecting this most important of
recording skills. Even if all the music you make is created via MIDI, the
chances are that at some time or other you'll have to record vocals using the
traditional tools of a singer and a microphone. The vocal line is invariably
the focal point of a song, so it has to be good, and because the human voice is
the natural sound with which we are most familiar, any flaws in a vocal
recording are immediately evident. Fortunately, providing you have a vocalist
who can sing in tune, getting a good vocal sound isn't rocket science -- you
just need to follow a few basic guidelines, and perhaps take advantage of a few
tricks of the trade to help you get a professionally produced vocal sound.
Make sure the singer is well rehearsed, physically comfortable, and
under no psychological pressure. Most singers perform best standing up in a
room that has a comfortable but not over-warm temperature. If they are
distracted by other members of the band or by hangers-on, send everyone but the
engineer (and producer, if you have one) out of the studio.
Take time to get the vocalist's headphone mix right, and give them a
little reverb to help them sing more confidently. If you can rig up a system
which allows vocalists to adjust their own monitor level, it will make life a
lot easier. A good headphone mix really helps to encourage a good performance.
Always use a pop shield between the singer and the microphone. Failure
to do so will almost certainly result in unnatural 'pops' on plosive 'b' and
'p' sounds that can't be fixed afterwards. The pop shield may be a commercial
model or a DIY job comprising stocking material over a wire coathanger frame
(one such design was explained in the Cheap Tricks article in SOS February
'95), or even a fine metal or plastic sieve or chip-pan splash guard. Any of
these will do the job without affecting the tone of the mic. Foam wind shields
are virtually useless in combating pops.
Use a good microphone: it doesn't have to be anything too special, but
you should avoid low-cost 'bargain' models or those designed for use with home
stereos or portable cassette recorders. Professional studios generally use
capacitor microphones, but in the project studio a good back-electret mic or
even a good dynamic vocal mic can produce excellent results. For more on these
different types of mic, see April's SOS.
Pick a mic to suit the singer. Singers with thin or excessively bright
voices may actually sound better with a dynamic mic, such as the ubiquitous
Shure SM58, while those needing more of an open sound would benefit from a
capacitor or back-electret mic. If you have several mic models to choose from,
try a test recording with each and see which is most flattering to the
vocalist.
Use the right mic pickup pattern: most project studio vocal recordings
are made using a cardioid or unidirectional mic, as these pick up less sound
from the sides and rear. However, an omni mic of a similar quality generally
imparts a more natural, open sound and that can be useful if you're working
with a singer who tends to sound nasal or boxy. If you work a couple of inches
closer to an omni mic, you'll get close to the same 'direct sound to room
sound' ratio you'd achieve with a cardioid.
Put the mic at the right distance, because if you get too close to it
you'll increase the risk of popping and the level will change noticeably every
time the singer moves slightly. Cardioid mics also exhibit a bass-boost
'proximity effect' that varies as the singer's mic distance varies. On the
other hand, if the singer is too far away from the mic the room reflections
will colour the sound, making it seem remote and boxy. As a rule, a mic
distance of around six to nine inches (15-24 centimeters) is ideal.
Minimize the room's influence on your sound. The mic picks up both
direct sound from the singer and reflected sound from the room. Reduce the
room's contribution by keeping away from the walls and by improvising screens
using sleeping bags or duvets behind and to the sides of the singer.
Use mic technique to help control level: if the singer can be persuaded
to pull back from the mic slightly when singing louder notes, there's less risk
of overloading the recorder or mic preamp, and you won't need to use so much
compression to even things up. An experienced singer may also lean into the mic
on quieter, more intimate passages to exploit the proximity effect. However, to
prevent an inexperienced singer getting too close to the mic, position the pop
shield about three inches (7.5 centimeters) from the mic.
Where possible, mount the microphone on a stand. Only let the singer
hold the mic if to do otherwise would compromise their musical performance.
When the singer is hand-holding a mic, particularly if it's a cardioid model,
make sure they keep their hand clear of the rear of the basket, as obstructing
this area can change both the directional and tonal characteristics of the mic.
Don't settle for anything less than the best vocal performance you can
get, and don't expect to get it all perfect in one take. More often than not
you'll have to punch in and out around phrases that need re-doing, but if you
have enough tracks, get the singer to do the whole song several times and then
compile a track from the best parts of each take. You can do this on tape by
bouncing the required parts to a spare track, but hard disk editing is much
more flexible in this respect.
Use suitable compression -- even well-disciplined vocalists tend to
sound uneven against the very controlled dynamics of a pop mix, so it helps to
apply a little compression while recording. Err on the side of using less
compression than you think you will finally need, and use a compressor that has
a reasonably neutral characteristic. Aim to achieve 5-8dB of gain reduction on
the loudest signal peaks, and if the compressor has an auto mode, use it.
Don't be afraid to use more compression on the vocal track once it has
been recorded. When the performance is in the bag you can try both subtle and
heavy compression to see which works best with the track, though if you're
using a lot of compression you may need to gate the vocal track first. This
will prevent noise build-up in the pauses between phrases. It's at the mixing
stage that a compressor with an obvious character can be used to make a vocal
seem larger than life.
Don't gate the vocal while recording. A badly set-up gate can ruin an
otherwise perfect take, so save gating until the mixing stage. Use the gate
before any further compression, but don't gate so hard that you remove all the
breath noises preceding words, as these are part of the character of a vocal
performance, and the recording will sound unnatural without them.
Don't run amok with the EQ: on most budget desks the EQ only sounds
decent when used sparingly or to cut unwanted frequencies. Mid-range boosting
usually results in a nasal or phasey sound, so use as little EQ as you can. If
you've picked the right mic, and taken the time to fine-tune its position
during recording, you shouldn't need much corrective EQ anyway. Of course,
there are times when EQ is used for creative purposes, and at such times it's
best to use a good-quality outboard equalizer, because the difference between a
budget EQ and a really good one is immense. Resist the temptation to pile on
too much high-end boost, as this will enhance sibilance, bring up background
noise and may make the end result fatiguing to listen to.
Use reverb sparingly: vocals recorded in a dry acoustic environment
need reverb to give them a sense of space and reality, but don't use more than
the song really needs. As a general rule, busy songs need less reverb and
slower ballads with lots of space in the arrangement can afford to use more.
Listen to some commercial records in a similar style to your own and see what
reverb techniques the producer has used.
If the vocals are very brightly recorded, they may cause any added
reverb to sound sibilant. Instead of de-essing the vocals (which often sounds
unnatural), try instead de-essing just the feed to the reverb unit. You can
also experiment with the reverb type and tonality to minimize sibilance and
spitting.
If you do have to de-ess the vocals, try to use a split-band de-esser
rather than the simpler compressor with an equalizer in the side-chain, as the
split-band approach produces fewer undesirable side effects. It's always best
to try to avoid sibilance by moving the mic slightly or by using a different
mic, rather than trying to fix it afterwards. Pointing the mic slightly above
or below the singer's mouth sometimes helps.
When you're using prominent echo or delay effects on a vocal, try to get them in time with the song, either by calculating the delay needed to match the tempo or by using the tap-tempo facility if one is provided. For a less obviously rhythmic echo, try a multi-tap delay with irregular tap spacings.
To ensure that the vocal is mixed at the right level in the song, listen to the mix from outside the room and see if the song has the same balance as something you might hear on the radio. The vocals are the most important part of the song and so must be well forward, but not so far forward that they sound 'stuck on' to the backing.
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