Digital Telephone Hybrid
Rio Rancho, NM
31
TEL (cont)
CODEC
AUX
Compressor Parameters (cont):
Ratio - The compression ratio is displayed here and can be adjusted from 1:1 (dis-
played as “Off”) to 50:1 (displayed as “INF:1”).
Makeup Gain - The makeup gain value is displayed here and can be adjusted from
0dB to a limit which is a function of the threshold and compression ratio. The makeup
gain value automatically responds to changes to the compression ratio so that it never
exceeds the limit set by the rule:
maximum makeup gain = gain reduction at full scale input
where the gain reduction at full scale input (+20dBu) depends
on the threshold and compression ratio selected.
Limiter Parameters: Limiter parameters are set by the following numerical controls. These
are identical in operation to the compressor setup controls described in Compressor
Parameters above.
Threshold - The limiter input level threshold is displayed here and can be adjusted
from -80dBu to +20dBu.
Time Constant - The limiter time constant is displayed here and can be adjusted from
0.1 to 500.0 ms.
Gain reduction meter: This meter displays the combined reduction in gain (in dB) that
results from compressor and limiter activity.
Amplitude response graph: Each output channel page contains a graph which displays
four plots:
A fixed plot for the 1:1 amplitude response used for reference (dashed grey line)
The amplitude response of the compressor (orange line)
The amplitude response of the limiter (dashed red line)
Total response, the amplitude response of the compressor and limiter plus makeup
gain (blue line)
These plots contain
handles which can be used as an alternative way to change the com-
pressor threshold (orange), compression ratio (green), limiter threshold (red) and makeup
gain (blue) with the mouse. Left click on a handle and move the mouse while keeping the
left mouse button down until the handle is positioned as you like. Release the left mouse
button and the adjustment is complete. As you do this the related numerical control will be
updated with the exact value corresponding to the position of the handle. The compres-
sor threshold handle moves along the 1:1 response diagonal, and the limiter threshold,
makeup gain and ratio handles move along the vertical axis.
Same as TEL
Same as TEL
Name
Description