Calibrating Loudness - Extron electronics DTP CrossPoint 4K Series User Manual

Calibrating Loudness

The basic gain structure is now set up. From this point, loudness can be calibrated using an
SPL meter, a critical ear, or a combination of the two.
Setting loudness using a meter
To calibrate loudness, use a sound pressure level meter set to "C" weighting.
1. Open the post-matrix loudness processor dialog box.
2. Bypass the loudness processor.
3. Place the meter in an average listening location.
4. Start your program material playback or generate pink noise.
5. Measure the SPL in the room.
6.
In the loudness dialog box, adjust the fader until the value in the "SPL" readout box
matches the reading on the SPL meter. Loudness is now calibrated.
NOTE: Calibration can be performed with the output channel volume set to
any comfortable listening level, but a relatively loud volume that can be easily
measured is preferred.
7. Release the bypass of the loudness processor to hear the compensation.
Alternate method:
NOTE: This method works if 90 dB is an acceptable amplifier or volume limit for the room.
1. Set the Loudness Compensation fader in the loudness dialog box to its default (center)
position and the output channel volume fader to 0 dB (100% volume).
2.
Adjust the amplifier until the SPL meter reads 90 dB. Loudness is now calibrated.
Setting loudness "by ear"
When setting loudness by ear, you must set up system gain structure first.
1. Open the post-matrix loudness processor dialog box.
2. Bypass the loudness processor.
3.
Place the meter in an average listening location.
4. Set the output volume fader to a relatively quiet listening level. Filter compensation
from the loudness processor is most prominent at low listening levels. Set to the levels
described earlier.
5. Set the Loudness Compensation fader in the loudness dialog box to its default (center)
position.
6. Release the bypass on the loudness processor to hear the compensation.
NOTE: You should hear a moderate enhancement to the program material with
more accentuated bass frequencies (below 500 Hz) and more brightness in the
high frequencies that carry harmonic content (above 7 kHz). You can toggle the
loudness bypass on and off to compare the difference between loudness off and on.
7. To experiment with less loudness compensation, move the Loudness Compensation
fader toward
8. Any adjustment you make to the Loudness Compensation fader carries through to all
listening levels. Set the DSP Configurator output volume to a relatively loud level.
9. Toggle the loudness bypass on and off to compare the difference between loudness off
and on. At a loud listening level, this difference should be minimal, or barely perceivable.
. For more loudness compensation, move the fader toward
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