Symetrix 601, Owner'S Manual

Page: 38 / 142

4-10
Rev 2.2, 10/31/94
These parameters are:
Name Purpose EditBuffer
Offset
Dynamics sidechain filter mode Changes the sidechain filter from
highpass shelving to lowpass. 0
Expander knee control Sets number of dB required to
reach ultimate expansion ratio. 49
Compressor knee control Sets number of dB required to
reach ultimate ratio. 55
AGC Threshold Absolute threshold for AGC 56
AGC knee control Sets number of dB required to
reach ultimate ratio. 60
ARM peak release time constant Determines the recovery time of
the auto-release monitor system. 62
ARM integration time constant Affects the signal level history of
the auto-release monitor system.
Shorter times require higher peak-
to-average ratios to release the
AGC hold. 63
ARM Signal/Noise threshold Sets peak/average ratio for
signal/noise decision 64
Dynamics control chain turnover
frequency Shelving highpass filter to limit
subsonic response of control
chain (sidechain). 65
Log converter time constant Initial log averaging time constant
for the dynamics sidechain. 66
Lookahead delay time Provides “thinking time” for
dynamics sidechain, which can
prevent overshoot. 67
De-ess absolute threshold Sets threshold for onset of de-ess
action. The relative threshold
affects the degree of de-ess action
after exceeding the absolute
threshold. 22
4.5.7.1 Sidechain filter
The dynamics section sidechain has a shelving highpass filter in its control chain that limits
the response of the dynamics section to very low-frequency sounds. The frequency (edit buffer
65) and mode (shelving highpass or lowpass, edit buffer 0) of this filter may be varied. The
default condition is shelving highpass.
In general, raising the filter frequncy, in highpass mode), makes the dynamics section
(compressor, AGC, and downward expander) less responsive to low-frequency sounds. This may
be useful for preventing p-pops from causing compression or opening the downard expander.