“SIX-PACK” OPERATORS’ MANUAL
8
OPERATION
The unit should be connected in line with the signal to be processed via suitable
insert points. For single channel use, each channel may be considered as being
completely independent and set up accordingly. For use with stereo or multi-
channel signals such as complete mixes or submixes, the unit should be switched
to Link mode and all setting up done using the master channel controls.
Setting up is simpler if the Expander is initially turned off and the Peak Limiter
threshold set to maximum. This allows the Compressor/Limiter to be set up in
isolation. The ratio setting depends on how firmly the signal dynamics need
controlling; as a rule, higher ratios provide a higher degree of control but also tend
to be more audible in operation when high levels of gain reduction are required. The
integral soft-knee feature of the “Six-Pack” renders these effects far less
pronounced, but this factor should still be taken into consid
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In general, a higher compression ratio may be used than on a conventional
compressor without compromising the sound quality.
If the Attack and Release controls are switched to Auto, setting up is now simply a
matter of adjusting the Threshold control until the desired amount of gain reduction
occurs. This is judged partly by ear and partly by observing the gain reduction
meter. In general, a maximum gain reduction of between 8dB and 12dB will be
adequate. If more gain reduction appears necessary, consider applying a
conservative degree of compression during recording and then further compression
while mixing.
Compressing during a mix does increase the subjective level of tape and other
background noises during pauses and quiet passages but, unless the noise
contamination is serious, the expander section will be able to attenuate it to a very
high degree without compromising the wanted signal.
At this point, the Auto control may be switched off if it is desired to set the attack
and release times manually. The longer the attack time, the longer the compressor
takes to respond to increases in signal level and a slow attack time is often used to
accentuate the beginning of percussive or plucked sounds such as drums, basses
and guitars. A fast attack time will bring the input signal under control very quickly.
The release time should be set short enough so that the system gain has returned
to normal before the next peak occurs and, in general, it should be set as short as
possible before audible gain pumping occurs.
At this point, the expander threshold may be set up and you should adjust the
release time settings to the least obtrusive in operation. For all but sharp percussive
sounds, a longer setting is likely to give the best results. Set the threshold using a
piece of program material that contains pauses and adjust the threshold to be as low
a dB level as possible while still attenuating the noise during pauses. Listen carefully
to how the sounds come in after the pauses and how cleanly they fade away again.
If you can hear the expander changing the sound in an unacceptable way, then the
threshold is probably set too high.
Because the expander is self-adapting to the programme dynamics, it should be
possible to obtain far more satisfactory results than are possible with conventional
expanders. By the same token, do not assume that because the expander threshold
