Telephone Rx (Dmp 128 C P And Dmp 128 C P At Only); Line Output Channels; Post-Mixer Trim Control (Trim); Loudness (Loud) - Extron electronics DMP 128 User Manual

Telephone RX (DMP 128 C P and DMP 128 C P AT only)
Figure 39.
The DMP 128 provides a telephone interface with separate input and output signal
processing paths. The telephone input (Rx) is identical to the other input processing paths
except the AEC block is not used. See
information.
NOTE: The country code must be entered before connecting the DMP 128 to a

Line Output Channels

There are eight mono line output channels. Controls and processing
blocks, identical for each output channel, are described in the
following sections.

Post-mixer Trim Control (TRIM)

The post-mixer trim control provides a fader for fine adjustment of the
program material prior to the output signal chain. The trim control has
a range of – 12 dB to +12 dB in 0.1 dB increments.
Default is unmuted at unity (0.0 dB) gain.

Loudness (LOUD)

The loudness processor block, when inserted, applies
a filter compensation curve to the signal in an inverse
relationship to the output volume control setting; the
higher the output volume setting, the less compensation is
applied (see
The loudness processor compensates for changes in human perception to varying volume
levels by applying a filter compensation curve to the signal in an inverse relationship to
the gain control setting. The higher the gain setting, the less loudness compensation is
applied. Generally, as volume is lowered, perception of certain frequencies is progressively
diminished, returning to a more flat response as volume is increased. Loudness will boost
those diminished frequencies to the highest degree at low volume levels, decreasing the
boost as volume increases.
Bypass must be disengaged for the loudness processor to function. The bypass button
is red when engaged (loudness control defeated), and gray when disengaged (loudness
control active).
Telephone Rx Signal Path
phone system.
Calibrating Loudness
Telephone Interface on page 127 for additional
on the next page).
DMP 128 • Software Control 59