Extron electronic MPX Plus 866 A Input clipping and clipping meters, Shift-Up/down arrow Shift

PRELIMINARY

Switcher Software, cont’d

Setting group master soft limits

• Shift in a combination moves the upper limit —
	Shift-Up/down arrow Shift	or Shift	— Moves the soft upper limit in
	0.1 dB increments.

 Shift-Page Up/Page Down arrow	Shift	Up	or	Shift	Down — Moves the soft
		Page			Page
upper limit in 10 dB increments.

 Shift-Home Shift Home — Moves the soft upper limit to the upper default.

 Shift-End Shift End — Moves the soft upper limit to the fader’s position.

•Ctrl in a combination moves the lower limit —

Ctrl-Up/down arrow Ctrl or Ctrl — Moves the soft lower limit in 0.1 dB increments.

	Ctrl-Page Up/Page Down arrow		Ctrl	Up or	Ctrl	Down — Moves the soft lower
				Page		Page
	limit in 10 dB increments.
	Ctrl-Home Ctrl	Home — Moves the soft lower limit to the fader’s position.
	Ctrl-End Ctrl	End — Moves the soft lower limit to the lower default.

Optimizing the Audio

Program material that you are familiar with is preferable for the following procedures, otherwise, pink noise can be used.

TThe Extron VTG 300 or VTG 400 is recommended to provide the pink noise.

Input clipping and clipping meters

Audio clipping is a form of distortion that occurs when the signal peaks (or excursions) exceed the limits of the circuit, cutting off the excursions of a signal. This condition gives audibly undesirable results. While it is difficult to clip the audio signal within the DSP audio signal chain, it is extremely important that the audio signal is not clipped before the input to the switcher. Once audio is clipped at the input, there is no remedy further down the signal chain. However, if audio clipping occurs at the output of the DSP that is not a result of clipping at the input, this can be addressed in the DSP audio signal chain.

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, selecting the Gain Defaults tab, and setting the clip threshold to a number between

0 dB and -20 dB. When the clip threshold is set to 0 dB, 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 MPX Plus 866 A, 0 dBFS corresponds to 22 dBu, which is the maximum output level of the switcher.

5-36 MPX Plus 866 A Media Presentation Matrix Switcher • Switcher Software