Extron electronics SSP 7.1 User Manual page 45

Output Trim
The Output Trim sliders control the audio signal level for each individual channel output.
Only channels that are enabled in the current speaker configuration are available; the others
are displayed but cannot be adjusted. Output trim is adjustable from -24 dB to +12 dB. The
current value for each output channel is shown in the text box.
Figure 24. Output Trim
NOTE: The maximum output volume is tied to the output trim. When an output trim
value is higher than 0 dB, the highest possible output volume is reduced by that
amount. For example, if the highest output trim for any channel is set to +5 dB,
the maximum output volume is -5 dB.
Extron recommends using a Sound Pressure Level (SPL) meter to set the output trim for each
speaker:
1.
Set up the SPL meter at the sweet spot in the room.
2. Send a test signal, generated
turn. Extron recommends using the Dolby Noise signal and sending the signals to the
speakers manually.
NOTE: The test signal should have a sound level at least 20 - 30 dB above ambient
levels.
3.
Measure and write down the sound pressure for each speaker.
4.
To avoid decreasing the maximum output volume (see the note above), Extron
recommends that you use the speaker with the lowest SPL reading as the zero reference
point. Then attenuate all the other speakers by the required amount to balance all
speakers.
as described on page 36, to each individual speaker in
SSP 7.1 • Setup and Control Software 39