172 Chapter 13—Dynamics Processors
01V—Owner’s Manual
THRESHOLD—This determines the input signal level at which compression and
expansion are applied. Signals at a level below the sum of the threshold and width are
attenuated by the expander. Signals at and above the thr eshold level are c ompressed by
the amount specified using the Ratio parameter. The trigger signal is sourced using the
KEY IN parameter.
OUT GAIN—This sets the compander’s output signal level. It can be used to compen-
sate for the overall level change caused by the compression and expansion processes.
WIDTH—This determines how far below the threshold level expansion is applied. The
expander is essentially turned off when the width is set to 90 dB.
ATTACK—This determines how soon the signal is compressed and expanded once the
compander has been triggered. With a fast attack time, the signal is companded almost
immediately. With a slow attack time, however, the initial transient of a sound passes
through unaffected. Attack times from 1 to 5 milliseconds are a good place to start.
RELEASE—This determines how soon the compressor and expander return to their
normal gains once the trigger signal level drops below the threshold. If the release time
is too short, the gain will recover too quickly causing level pumping (i.e., noticeable
gain fluctuations). If it is set too long, the compressor may not have time to recover
before the next high level signal appears, and it will be compressed incorrectly. R elease
times from 0.1 to 0.5 seconds are a good place to start.
RATIO—This determines the amount of compression. That is, the change in output
signal level relative to change in input signal level. For a 2:1 ratio, for example, a 10 dB
change in input level (above the threshold) results in a 5 dB change in output level. For
a 5:1 ratio, a 10 dB change in input level (above the threshold) results in a 2 dB change
in output level. The expander ratios are fixed: 1.5:1 for the soft compander (S) and 5:1
for the hard compander (H).
Parameter Range
THRESHOLD –54 dB to 0 dB (55 steps)
OUT GAIN –18 dB to 0 dB (0.5 dB steps)
WIDTH 1 dB–90 dB (1 dB steps)
ATTACK 0–120 ms (1 ms steps)
RELEASE 5 ms–42.3 s (fs = 48 kHz)
6 ms–46 s (fs = 44.1 kHz)
RATIO 1:1, 1.1:1, 1.3:1, 1.5:1, 1.7:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 5:1, 6:1, 8:1,
10:1, 20:1 (15 steps)