System Configuration ~ Inputs and Outputs

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Optimizing input gain structure

How you adjust an input’s gain directly affects sound quality. The optimal input gain

setting is one which is adjusted as high as possible above the noise floor without

introducing clipping. Clipping can cause distortion which can damage amplifiers and

loudspeakers.

To adjust the input level properly, place a signal on the input at the maximum

level it will generate. Adjust the input gain until the peak level of the input, as

shown on the Input meter, just begins to enter the red (clipping) zone, then reduce

the gain slightly until peaks no longer climb into the red zone. This setting will

ensure that the XAP 400 maximizes the signal-to-noise ratio without clipping the

signal.

Meters

There are four meters on each mic/line input to assist with setup and level control.

Select the meter check box to enable the meter. All input meters are peak-level.

Figure 3.44 Meter locations in the Inputs 1–4 signal path

Pre Gain

Pre Gain meter indicates the input’s level before gain adjustments. Meter range is from -85 to -35dB when 55dB gain is selected; -55 to -5dB when 25dB gain is selected; and -65 to 20dB when 0dB gain is selected.

Post Gain

Post Gain meter shows the input’s level after gain adjustments have been made. Meter range is from -30 to +20dB.

Post Processing

Post Processing meter indicates the level at the gating point after the signal has passed through input processing. It reflects the post-AGC signal. Meter range is from -30 to +20dB.

Post Gating

Post Gating meter shows audio level after it has passed through the gating

parameters. Meter range is from -30 to +20dB.

Figure 3.45. Mic input meters

Technical Services Group ~ 1-800-283-5936 (USA) ~ 1-801-974-3760

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ClearOne comm XAP 400 operation manual Meters