DTP CrossPoint 84 Series Matrix Switchers • Matrix Software 126
Meters are available in the gain controls ( ) and in the dynamic processor blocks ( ) when
the program is in Live mode and an audio signal is applied to the DSP. The meters in the
DSP Configurator program indicate clipping at a user-definable level, with the default setting
at -1 dB. At the -1 dB setting, the meter indicates clipping when it reaches -1 dBFS, or 1
dB below actual clipping. Setting the clipping meter below actual clipping provides a bit of a
“safety net,” letting you know to pull back on input gain before clipping actually occurs. You
can increase or decrease this safety net by clicking Tools > Options > Defaults tab >
Meter Clipping tab, and setting the Clip Threshold
to a number between 0 (dB) and -20. When the clip
threshold is set to 0, clipping is indicated only when actual
clipping occurs.
Meters within the DSP Configurator program are peak-type meters, referenced to “full
scale,” or 0 dBFS. For the DTP CrossPoint 84, 0 dBFS corresponds to 22 dBu, which is the
maximum output level of the switcher.
Setting the Input and Output Gain Structure
Before calibrating loudness, set up the system gain structure.
1. Set the signal generator to output -10 dBFS or use recorded program material at
-20 dBFS.
2. Set the input gain in the DSP Configurator so that the input meter reads -20 dBFS.
NOTE: In step 3, if using a recorded source and the player has an output level
setting control, ensure that the output of the player is set to its maximum, or 0 dB
of attenuation.
3.
For pr
ogram material, set the input level to approximately -15 dBFS, with peaks
at no more than -5 dBFS to -3 dBFS. This setting provides enough headroom to
accommodate transients or unanticipated loud events in the program material in order
to avoid possible clipping.
4.
T
ie the audio from the source to the speakers that will carry program material in the
room to be calibrated.
5.
W
ith the output channel volume set to -20 dB, listen to the audio output while you
set the external amplifier so that the source material plays at a volume level that is
reasonably loud but tolerable. Verify that the amplifier is not clipping by observing the
amplifier clip indicator.
Adjusting the Pre-matrix Trim
The pre-matrix trim control can be used to compensate for any level changes caused by
signal processing before the trim control. Adding a compressor generally reduces the signal
level, while a filter can either boost or cut the overall signal level.
NOTE: This procedure is valid only if no processing is active in the output signal path,
and if post-matrix trim value is set to 0 dB (unity gain). If you have processors inserted
in the output signal path, open them and bypass them to temporarily remove them
from the signal path.
1. After you have set the input gain, add any processors that you wish to use into the
input signal chain.
TIP: If you make changes to filter settings after you have set your dynamics
processors, recheck the levels in your dynamics processors to make sure that they
are still valid.
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