BSS Audio DPR-901II Owner's Manual - Manual (Page 15)

15
Controls
When the switch is released, the processing operates above threshold,
that is with compression or expansion being applied only to signal levels
that exceed the threshold. When the switch is depressed to select Below,
the green led beneath the switch lights. The threshold’s sensitivity setting
remains the same, but the processing is ‘turned on its head’ as compres-
sion or expansion is now only applied to signals which are below the
threshold. Below threshold compression now works like a frequency-
sensitive gate in that the further below the threshold the signal is, the
more it is attenuated. There being progressively less attenuation as signal
level increases to approach the threshold setting. Below threshold expan-
sion acts to boost the selected frequency range up to (but not above) the
threshold. The expansion meter 9 will light under these low signal
conditions, slowly reducing as the input signal increases towards thresh-
old.
When the switch is released, the compress/expand time constants are
automatic. This is the normal setting if you’re using the DPR-901ii as a
leveller or otherwise processing a composite (mixed down) music signal.
When depressed for FAST, the compress/expand release time is speeded
up. This is likely to be the correct setting for less spectrally dense mate-
rial, normally single instruments, especially dynamic sources, ie. vocals,
percussion and any instruments played percussively.
14 BELOW Threshold
15 FAST RELEASE