USL CM-8E - Manual (Page 22)

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selected. These settings also affect the web bar graph display. If biamp audio is available on the
processor or amplifier, the individual bands are shown on the bar graph. The crossover type
can be biamp or none.
The CM-8E allows for monitoring of the individual LFE amplifier returns. Select the number of
LFE amplifiers that are used in this auditorium. The front panel and web LFE buttons allow
sequencing through the individual LFE returns when the amplifier is selected (instead of the
processor). In addition, the individual LFE returns are shown on the web bar graph when the
amplifier is selected.
The CM-8E includes compressors for the speaker and web stream. These reduce the dynamic
range to be suitable for these applications. The attack and release times are adjustable, though
the default values are normally suitable. A significantly slower attack time can cause clipping
because the compressor would react too slowly to a loud sound. A shorter release time
increase the average volume but can result in low frequency distortion as the compressor
starts to follow low frequency waveforms.
Once the settings on this page are complete, press the “Save Settings” button.
6.6 Bar Graph Calibration
The CM-8E is calibrated to show 0dB with processor and amplifier return (through the DE-15
connector) levels of 300mVrms. This is correct for most installations. However, you can adjust
the bar graph calibration for your particular installation. Click the “Bar graph” link at the top of
the audio configuration page to get a page similar to that shown below.
Play pink noise on a channel at reference level. Select only that channel using the front panel or
web buttons. A bar (or two for biamp) should appear above the button corresponding to that
channel. Click the mouse in the top box above the button to increase the height of the bar and
the bottom box to decrease the height of the bar. As shown in the image above, when a