Snoman R. Dance Music Manual: Tools, Toys, and Techniques

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■ Gain make-up: Increase the gain so that it is 3 –5 dB above pre-compression

level

BAND 2: TO TIGHTEN UP THE MIX IN GENERAL AND ADD WARMTH TO

INSTRUMENTS AND VOCALS

■ Frequency: 120 Hz–2 KHz

■ Ratio: 2.5:1 or 3:1

■ Threshold: Just above the quietest notes so that it is triggered often but

not continually

■ Attack: 20 –30 ms

■ Release: 100 –160 ms

■ Gain make-up: Increase the gain so that it is 1 –3 dB above pre-compression

level

BAND 3: TO INCREASE THE CLARITY OF INSTRUMENTS

■ Frequency: 2 –10 KHz

■ Ratio: 3:1

■ Threshold: 2 dB below the quietest notes so that the compressor is per-

manently triggered

■ Attack: 10 –20 ms

■ Release: 100 –180 ms

■ Gain make-up: Increase the gain so that it is 2 dB above pre-compression

level

BAND 4: TO INCREASE THE CLARITY OF MID- TO HIGH-FREQUENCY

INSTRUMENTS

■ Frequency: 10 –16 KHz

■ Ratio: 2:1 or 3:1

■ Threshold: Just above the quietest notes so that it is triggered often but

not continually

■ Attack: 5 –25 ms

■ Release: 100 –140 ms

■ Gain make-up: Increase the gain so that it is 1 dB above pre-compression

level

Five-Band Compression

BAND 1: TO TIGHTEN UP THE BOTTOM END OF A MIX

■ Frequency: 0 –180 Hz

■ Ratio: 5:1

■ Threshold: 3 dB below the quietest notes so that the compressor is per-

manently triggered

■ Attack: 10 –20 ms

■ Release: 130 –190 ms

■ Gain make-up: Increase the gain so that it is 3 –5 dB above pre-compression

level

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BAND 2: TO TIGHTEN UP THE RHYTHM SECTION AND THE MIX IN

GENERAL

■ Frequency: 180 –650 Hz

■ Ratio: 2.5:1 or 3:1

■ Threshold: Just above the quietest notes so that it is triggered often but

not continually

■ Attack: 10 –20 ms

■ Release: 130 –160 ms

■ Gain make-up: Increase the gain so that it is 1 –3 dB above pre-compression

level

BAND 3: TO ADD SOME WEIGHT TO THE MIX AND INCREASE ITS

ENERGY

■ Frequency: 650 Hz–1.5 KHz

■ Ratio: 3:1

■ Threshold: 1 dB below the quietest notes so that the compressor is per-

manently triggered

■ Attack: 15 –25 ms

■ Release: 100 –130 ms

■ Gain make-up: Increase the gain so that it is 1 –3 dB above pre-compression

level

BAND 4: TO INCREASE THE CLARITY OF MID- TO HIGH-FREQUENCY

INSTRUMENTS:

■ Frequency: 1.5 –8 KHz

■ Ratio: 2:1 or 3:1

■ Threshold: Just above the quietest notes so that it is triggered often but

not continually

■ Attack: 5 –10 ms

■ Release: 100 –140 ms

■ Gain make-up: Increase the gain so that it is 1 –4 dB above pre-compression

level

BAND 5: TO REDUCE UNWANTED ARTEFACTS SUCH AS A ‘ ROUGH ’ OR

‘ HARSH ’ TOP END

■ Frequency: 8 –16 KHz

■ Ratio: 2:1 or 3:1

■ Threshold: Set so that it is triggered occasionally on the highest peaks

■ Attack: 5 ms

■ Release: 100 –140 ms

■ Gain make-up: Increase the gain so that it is 1 dB above pre-compression

level

As always, these are not precise settings and are only listed as a general guide

to begin with. With these settings dialled into the compressor, you will need

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to experiment by increasing and lowering the make-up gain, the threshold, the

attack, the release and the ratio while listening for the difference each has on

the mix. Also, remember to bypass it often and compare it with the uncom-

pressed signal, ensuring that you’re not destroying the dynamics of the mix .

HARMONIC EXCITERS

Following compression, some engineers may send the mix out to a harmonic

exciter to add some extra sparkle to the mix. This is a moot point among many

engineers, as some regard any harmonic excitement as sounding too artiﬁ cial.

Nevertheless a proportionate amount of music released today will have been

‘ cooked’ with some form of enhancement to increase the overall resolution of

the music.

The main reason behind applying any form of psychoacoustic enhancement to

a mix stems from the introduction of modern recording techniques. As we now

have the ability to record and re-record music, the clarity and detail of music is

usually compromised, particularly in the higher frequencies.

This results in the music’s frequency content seeming dreary, dull and lifeless.

When an enhance is used, these dulled or missing frequencies can be restored

or replaced, in effect making the music appear clearer, brighter and crisper.

While this seems relatively simple in principle, in application it is much more

complicated as there are various enhancers available and each uses different

methods to brighten the mix.

The ﬁ rst exciters were developed by the American company Aphex in 1975 and

were, according to the story, discovered by accident. A stereo ampliﬁ er kit was put

together incorrectly ending up with only one channel working, the other giving a

thin distorted signal. When the channels were mixed together the resulting signal

came out sounding cleaner, brighter and generally more enhanced.

This principle was researched and developed before a conclusion was reached

that adding controlled amounts of speciﬁ c harmonic distortion to an audio

signal can actually enhance it. Originally, the ﬁ rst Aphex exciters were only

available for rent to studios at around £20 per minute of music, but due to the

overwhelming demand they soon became available for purchase. These com-

mercial units work by allowing you to select low-, mid- or high-range frequen-

cies, which are then subsequently treated to second- and third-order harmonic

distortion. This distortion is then added back to the original audio before the

whole signal is treated to small amounts of phase shifting.

This form of synthesizing additional harmonics from an original signal is only

used by the Aphex exciters. Many engineers prefer this but some don’t like the

idea of applying any distortion to a mix and so use enhancers instead. Aphex

registered the name Aural Exciter to its family of exciters; all other manufactur-

ers refer to their exciters as psychoacoustic enhancers. These are available from

Behringer, SPL and BBE, to name a few.

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Each of these utilizes slightly different forms of enhancement, many of which

are secrets closely guarded by the manufacturers. Most of this is probably

because even they can’t explain why what sounds normal to our ears informs

our brains that something extra special is happening. And although I would

love to explain the details of why psychoacoustic enhancements sound so spe-

cial, (a) it would take up most of this book to explain and (b) it would also

involve me knowing why. Nevertheless, I can say that they are all based around

some form of dynamic equalization and phase alignment.

Much of what we determine from a sound is derived from the initial transient,

but during the recording process and subsequent processing the phase can be

shifted, which results in the transient becoming less noticeable. Realigning the

phase using an enhancer makes these transients more deﬁ ned which results in

extra clarity and deﬁ nition.

Most enhancers and exciters are single-band, either allowing you to specify the

frequencies you wish to enhance or simply enhancing all of the frequencies at

once. However, some enhancers, such as Izotope’s Ozone, also offer individual

control over numerous bands of ‘enhancement’, allowing you to process dif-

ferent frequency bands separately. Generally speaking these types of enhanc-

ers introduce second-order harmonic distortion into the original signal which

makes them suitable for adding the typical tube emulation throughout the fre-

quency range.

Ultimately, although applying an extra sonic sheen to music will make pretty

much anything sound better, enhancers should be used conservatively. The

results they produce can be extremely addictive and our ears can grow accus-

tomed to the processing quickly. This can result in overprocessing (often

referred to as ‘overcooking ’ or ‘frying’) which results in a sound that can be very

fatiguing to the ear. Thus, like all other effects they should be used sparingly.

STEREO WIDTH

Following the excitement effect, a proportionate amount of mixes will also be

sent through a stereo widening effect to increase the overall image of the mix.

This is a very simple effect and requires little explanation, as usually if will only

offer a percentage parameter. When this is increased, the width of the stereo

image will be perceived to be wider than it actually is.

This works on the principle that sounds that are shared in both left and right

channels can appear to be in the middle of the mix rather than panned to either

side, even if they are. However, if you were to subtract one of these channels from

the other then the phase would be adjusted, resulting in a wider stereo effect.

Like any other mastering process, overuse of stereo widening effects can have

a detrimental effect on the music, so they must be applied carefully. This is

because as you widen the spectrum further left and right the phase adjustments

can create a ‘hole’ in the middle of the mix and as the bass, kick drum and

vocals are usually located here the result can be a distinct lack of body, or in

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extreme cases a total removal of body. To avoid this, some mastering modules

will allow you to adjust frequency bands individually. In this case, it’s worth-

while widening the high frequencies but applying less to the mid-range and

the bass consecutively.

LOUDNESS MAXIMIZERS

The ﬁ nal link in the chain is the loudness maximizer. The basic premise of this is

to reduce the volume level of any peaks so you can increase the relative volume

of the rest of the mix without fear of overloading the signal. This is similar to

the operation of a limiter, in that loudness maximizers establish a strict dynamic

maximum but unlike typical limiters, loudness maximizers are designed to more

natural sound by ‘rounding off ’ any peak signals rather than cutting them dead.

This approach to increasing the relative volume of a mix is preferred to normal-

izing on an audio editor as this can introduce unwanted artefacts.

As previously discussed, when audio is normalized, the ﬁ le is ﬁ rst scrutinized

to locate the loudest waveform peaks. Then the volume of the entire section of

audio is increased until these peaks reach the digital limit. Theoretically, this

should raise the volume without introducing any unwanted artefacts, but any

digital recording will sound much better if the waveform was captured as a loud

signal in the ﬁ rst place. If you artiﬁ cially increase the gain using normalization,

it will often reveal the limitations of digital recording. What’s more, as it raises

the volume in direct relation to the peaks, while it may appear louder we do not

perceive volume by the peaks in a signal but through the average volume.

Loudness maximizers limit the distance between the peak and main body of

the music, which increases the volume more substantially. This does, how-

ever, mean that the more maximization that is applied to a mix, the more the

dynamics will be reduced, so like any other processor loudness maximizers

must be used cautiously. Ideally you want to keep a peak-to-average ratio of at

least 4 or 5 dB, or perhaps more if you want the kick drum to really stand out

(keep a large excursion).

Due to their simple nature, most maximizers will consist of only a few con-

trols: a threshold, a make-up gain (often known as a margin), a release and the

option to use either brickwall or soft limiting. These functions are described in

the following sections.

THRESHOLD

Similar to a limiter and compressor, the threshold on a loudness maximizer is

used to set the level where the limiting will begin. When the loud is reduced,

more of the signal will be limited, whereas increasing it will reduce the amount

of the signal being limited. Where this should be set is determined by the mix in

question but as a general rule of thumb, it should be adjusted so that only the

peaks of the waveform (usually the kick drum) are limited by a couple of deci-

bels while ensuring that the excursion between the kick and the main mix is not

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compromised to less than 4 dB. For most competent mixes (i.e. those that have a

good signal level) the threshold will usually be set around ⫺1 to ⫺4 dB.

MAKE-UP GAIN (AKA MARGIN)

This is similar to the make-up gain on a typical compressor and is used to

set the overall output level of the mix after ‘limiting’ has taken place. Broadly

speaking, it isn’t advisable to increase this so that the output level is at unity

gain. Rather, it is more prudent to set this 1 dB lower just in case any further

processing has to take place.

RELEASE

Again, the release parameter is similar to that on a compressor and determines

how quickly the limiter will recover after processing the signal. Ideally, this

should be set as short as possible to increase the volume of the overall signal, but

if it is set too short the signal will distort. The best way to set the release param-

eter is to adjust it to its longest setting and gradually reduce it while listening to

the mix. As soon as the mix begins to distort or slice, increase the time so that it’s

set just above these blemishes. You’ll usually ﬁ nd that the more limiting that is

applied to an audio ﬁ le, the longer this release setting will need to be.

BRICKWALL/SOFT LIMITING

Most mastering limiters or loudness maximizers are described as being

brickwall or soft, and some will offer a choice between the two modes.

Fundamentally, if the maximizer is particularly good then these will both pro-

duce similar natural results, but soft limiting may appear more transparent

than brickwall, depending on how hard the limiter is being pushed.

When you use a soft limiter, the overall level can exceed unity gain if it is

pushed too hard but if not it will produce results that are generally seen as

more natural and transparent than with brickwall. Alternatively, when you use

a brickwall setting, no matter how hard the limiter is pushed it will not exceed

unity gain, but if it is pushed too hard the limiter may have a difﬁ cult time

rounding off the peaks of the signal resulting in a sound that’s best described

as ‘crunchy ’ or ‘digital’. The choice on which to use is dependant on the mix,

but a soft setting will often produce better results on a mix.

GENERAL MASTERING TIPS

■ Avoid the temptation to master your own music

All mastering engineers are impartial to the music and they will have a subjec-

tive viewpoint on the music. You will not be aware of your bias due to your

involvement in the project. Even if you are not willing to employ a professional

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mastering engineer, ask a knowledgeable friend or fellow musician to master

your music for you. Another person’s interpretation can produce results that

would never have crossed your mind.

■ If at all possible use full-range, ﬂ at monitors

Both vinyl and CD are capable of producing a frequency range that is beyond

the capabilities of all nearﬁ eld monitors and if you can’t hear the signal you

can’t judge it accurately. Mastering engineers will use monitors that are incredi-

bly ﬂ at but which, although they sound a little bland, guarantee that the music

will play properly on all sound systems.

■ Monitor at a ﬁ xed volume

Adjust the monitoring volume so it is at a ﬁ xed comfortable volume. Loud

monitoring volumes will tire your ears more quickly and affect the frequencies

of the mix due to the Fletcher Munson contour control. Once the volume is

set, listen to some professionally mastered CDs and compare them with your

own mix.

■ Always reference your track with a professionally mastered track

This is possibly the best way to train your ears. By continually switching

between your own music and a professionally mastered track you will be able

to keep some perspective on your current work.

■ Always perform A/B comparisons

Our ears become accustomed to tonal changes relatively quickly, so after apply-

ing any processing, perform an A/B comparison with the unaffected version.

■ If it isn’t broke, don’t try to ﬁ x it

One of the biggest mistakes made by many musicians is to immediately jump

in and start adjusting the EQ and/or multi-band compression without actually

listening to the mix ﬁ rst. Itchy ﬁ ngers will inevitably produce a poor master, so

listen to the mix thoroughly before touching anything. The less processing that

is involved during the mastering stage, the better the overall results will be.

■ Avoid using presets or wizards

All music is different, so always use your ears rather than someone else’s idea of

what the EQ or compression should be. Also, bear in mind that the approach

is different from one track to the next, so don’t think that mastering settings

from a previous track will work on the next.

■ Do not ﬁ nalize anything as you’re recording to external hardware such

as DAT

Unlike computers, DAT machines do not have an undo function and if you

apply the wrong settings at this point there is no going back.

■ Do not normalize a mix

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All normalizing algorithms look for the highest peaks and then increase the

volume of the surrounding audio, but the ear doesn’t respond in the same way.

Rather, it judges the loudness of music by the average level.

■ Do not apply any processing that is not vital to improving the sound

Simply because some may mention that a certain process is used in mastering

do not take it for granted on your own mix. Every DSP process comes at the

cost of sound quality. The less processing you apply to a mix during the mas-

tering stage, the better it will eventually sound.

■ If possible, use a VU meter to measure the levels of the mix

Although VU meters are considered old hat compared to the latest digital peak

meters, VU meters are much more suitable for mastering. A digital peak meter

only measures the loudest peak of a signal; thus, if you have a drum loop mea-

sured by one it will seem as though the level is particularly high even though it

may be quiet. Conversely, a VU meter generally measures the overall loudness

(RMS).

■ Keep the bit rate as high as possible and only dither (if required) before

it is recorded

Use as many bits as possible in the mix until it is ready to be copied to the ﬁ nal

media. If you continually work with 16-bit throughout the recording and mix-

ing, further processing such as raising the gain will truncate the overall sound.

Always bear in mind that the more bits that are contained in a signal, the better

the signal-to-noise ratio with less chance of distortion being introduced.

■ Use a top-quality soundcard with the best software you can afford

Poor-quality soundcards will reduce the overall quality of the end results, and

poor dithering algorithms will reduce the quality further.

■ Make sure that the headroom is optimal

Ensure that the faders on the mixing desk are not too far below their optimum

0 dB and that the main mix output signal is around 0 dB (or ⫺ 15 dbFS for digi-

tal signals). Keeping them too far below this can often result in compensating

for it by adding more volume at the ampliﬁ er which can result in a loss of tran-

sients at the recording stage.

■ Learn your mastering processors

Learn the effect that each processor has on a mix, and unless you’re experi-

enced, create a number of takes using a mix of gentle and aggressive settings.

Write these settings down, copy the audio to CD and then play it on as many

systems as possible. All engineers have learnt the most from previous mistakes

so don’t be afraid of making them. It’s much better to make a mistake in pri-

vate than in public.

■ Avoid using a noise gate

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Although noise gates are useful for removing any potential noise during silent

passages, they can also result in clipping as the sound stops or starts. It is more

prudent to leave any potential noise in. You can remove ir by applying the

noise reduction software over just the noisy part and you can use it to create a

noise proﬁ le if it is present throughout the track.

■ Avoid using rapid fades

If there is noise present at the end of a recording, don’t try to avoid it by rapidly

fading the music down to nothing as this may result in cutting off the end of an

instrument. A better approach is to leave the recording running for a few sec-

onds longer and then use noise reduction software to remove the problem. As

with the above tip, any noise present here can also be used as a noise proﬁ le.

■ Always check your mastered mix in mono

If the track is destined for radio play, it is imperative that it sound well in

mono as well as stereo. Although a majority of radio stations broadcast in ste-

reo, slight signal discrepancies can result in the mix being received in mono. If

the mix has not been checked for mono compatibility it could sound drasti-

cally different.

■ Consider decreasing the tempo of the master

It isn’t unusual for some radio stations to increase the tempo of a track so they

can cram in more commercials throughout the day. This is only by a few beats

per minute but nevertheless, if a song is destined for radio airplay it is some-

times worth time-stretching the track to a slower tempo. This way, when the

radio station speeds the track up it will be back at its original tempo.

■ Use the best CD burner that you can afford

If the ﬁ nal media for a mastered mix is CD, then it is vital to use a high qual-

ity CD burner. These are not only more reliable but will also reduce the num-

ber of errors that can be introduced onto the disc. Additionally, although many

CD burners can record at speeds of 40 ⫻ and above, it is advisable not to record

at speeds greater than 4 ⫻ . Apart from preventing the chance of buffer underrun

(CDs are recorded in one continuous pass and if the computer cannot deliver

data fast enough an interruption will occur and destroy the recording), if the burn

rate is too fast crackling and distortion can appear on quieter passages of music.

■ Use quality blank CDs

This may seem like common sense, but many musicians use cheap quality CDs

in an effort to save some money. Silver and gold dye on CDs will invariable

perform better than dark green, and if you value your music it is worthwhile

spending a little extra for a better recording quality.

■ Do not use CD labels

The typical sticky paper labels should be avoided because they can often

increase the CDs error rate. This is not usually perceptible on many CD players,

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but it will degrade with age and low error rates are required by mastering

plants. Ideally, you should use a speciﬁ cally desinged for CDR pen and try to

write outside the area where the data is recorded.

■ Avoid using 80-min CDs

Despite the manufacturer’s claim that 80-min discs are as reliable as 74-min

CDs, they have a tendency to introduce distortion, so stay with 74-min CDs.

■ Use a professional mastering plant

If the record is for the public market (hi-ﬁ players, vinyl etc.) you should very

seriously consider taking the recording to a professional – the difference can be

remarkable and worth the additional outlay. Mastering is a precise art and you

really do need golden ears to produce an accurate master copy.