BSS Audio OPAL Series DPR-944 Owner's Manual - Manual (Page 24)

2 4
Fig 9.2 Effect of
'Progressive knee'
compression
9.4 Release fast
With the release fast switch in the out position, the DPR 944 operates in an
auto mode. This feature of the DPR 944 is provided to overcome some of the
conflicting setting requirements associated with conventional attack and
release controls. The DPR 944 automatically adjusts itself to provide the
required attack and release time settings, dependant on the program content.
Auto mode uses a combined program related attack time setting and a two
part program related release time setting. The two part program dependant
release provides a fast release to restore below threshold gain as soon as the
transient has passed, and a much longer following release to avoid rapid gain
change effects.
Operation with the release fast switch out will cater for the vast majority of
applications, providing a very unobtrusive ‘musical’ compression. If the
release time is found to be too long for a given application, depressing the
release fast switch will speed up the release about 10 times, and may be more
appropriate for processing percussive sounds.
Care should be taken when the switch is in, as too fast a release time for a
given program type can cause the overall volume level to jump up and down,
exactly following the signal peaks. This can produce an objectionable and
unsettling effect; quiet parts of the program immediately following loud
transients will be subjected to ‘breathing’ or ‘pumping’ effects caused by the
VCA releasing its attenuation (or effectively increasing the system gain)
during the quiet program period, when it is not required.
Control operations - Compressor