Drawmer DC2476 Digital Mastering Processor - Manual (Page 33)

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Both the full band and split band compressors work using Drawmer’s ‘bootstrap’
control system so that as more compression is applied, the overall gain is
automatically increased to compensate. Once you are used to this method
of working, you’ll find it much more intuitive than the traditional way of working,
but you should be prepared to spend a little time experimenting with it in
order to get the best out of it.
The expander and gate operate much like their analogue counterparts, except
that being spread over three frequency bands, any side effects are far more
benign. It’s probably fair to say that these are most useful when treating
individual tracks, but even when working on full mixes, they can be used to
ensure a clean start to the mix. However, if further editing using a hard disk
editing system is anticipated, it is generally safest not to attempt to gate the
start or end of a song, or to use the autofade facility, as these functions can
invariably be controlled more precisely via a digital audio workstation.
When setting up a new patch from scratch, one of the first decisions to be
taken is where to set the crossover frequencies for the split band section.
Intense multiband processing can adversely affect vocals, so it’s generally
best to keep the crossover points away from the main part of the voice
spectrum. For most material, this means keeping the low crossover point
below 200Hz and the high crossover point above 4kHz, though for general
applications, crossover points at around 100Hz and 6kHz might be more
typical. By keeping the low crossover point reasonably low, it’s possible to
exercise considerable control over the bass end of a mix without affecting the
mid range or high end.
Different engineers prefer to start by setting up compression or equalisation
first, but if both are being used together, it’s important to make final adjustments
when both blocks are active as the settings tend to interact. When compressing
complete mixes, low compression ratios combined with lower than normal
thresholds tend to produce the most musical results.
The dynamic equaliser section is particularly useful for emphasising transient
events without over-equalising the overall mix, for example, to add weight to a
kick drum or bass guitar. Again, the best results are generally achieved by
using restraint, and as with EQ, narrow band boosts tend to be more obvious
than narrow band cuts. Experienced engineers will know this already, though
anyone still feeling their way in mastering can learn a lot by examining the
factory presets to see what settings are used.
One of the major achievements of the DC2476 design is the equaliser section,
which sounds far more analogue and musical than most digital equalisers.
Those who have had previous experience with digital equalisers may have
noticed that it’s sometimes necessary to apply rather large amounts of cut or
boost to achieve the same approximate result as from an analogue equaliser.
With the DC2476, you can use the equaliser exactly like its high quality
analogue counterpart, which means small changes can make large audible
differences.
The inclusion of split band tube modelling allows the timbre of a track or
complex mix to be altered in both subtle and not-so-subtle ways. Altering the
drive level to each band changes the spectral balance of mix in the same way
that adjusting a three band equaliser would, but as the drive level is increased,
the soft saturation algorithms come into play, gently reshaping the signal in
much the same way as a true tube circuit, but without the noise. Adding
more drive to the high and low bands recreates the classic ‘smile’ loudness
curve while making the overall mix sound more rich and detailed, but it’s also
possible to use the equaliser section in conjunction with the tube emulation
block to make even more subtle changes. This is one area where
experimentation will be rewarded, but as a general rule, modest drive levels
work best on complex mixes with more aggressive settings being useful for
treating individual tracks.
The three-band limiter only operates when signals are at such a high level
that they would otherwise have clipped. Like the gain management limiters,
this may be best considered as a safety feature, though it can be employed
to increase the subjective loudness of a mix by deliberately driving the top 3
or 4dB of signal peaks into limiting. Because the three bands are handled
separately and with optimised time constant, the style of limiting is far more
transparent than that produced by the gain management safety limiters.