Extron electronic MVX 44, MVX 88, MVX 84, 48 manual Adjusting Input Audio Gain and Attenuation

Adjusting Input Audio Gain and Attenuation

Switchers have input audio gain and attenuation adjustments. In Audio Setup mode, the audio level of each input can be adjusted through a range of –18 dB to +10 dB. This adjustment range ensures that there is no noticeable volume difference among sources. It also eliminates the need for separate preamps or attenuators when used with professional (higher line level) and consumer (lower line level) audio equipment (see figure 12).

dBu	dBv																			dBu	dBv
																				+10	+8
+10	+8
																				+7	+5
+7	+5																			+4	+2
+4	+2																			+1	-1
+1	-1																			-2	-4
-2	-3				Laptop															-5	-7
-5	-7	Audio																		-8	-10
-8	-10																			-12	-14
-12	-14	Inputs																		-18	-20
-18	-20																			Output
Low Audio
																				Level
Output Level
																				MVX SERIES
						INPUTS								OUTPUTS						VGA/AUDIO MATRIX SWITCHER
		1	2	3	4	5	6	7	8	1	2	3	4	5	6	7	8	ENTER	PRESET	I/O
																				VID +dB
																				AUD -dB
																				AUDIO SETUP

		Audio		MVX VGA A Series Switcher	Audio System
dBu	dBv	Inputs
+10	+8				No noticeable volume
+7	+5
+1	-1	VIDEO INPUT		differences between sources
+4	+2	DAV101CM	VGA LINE DRIVER
			POWER
-2	-3
-5	-7	DAS101 CM
-8	-10
-12	-14
-18	-20

High Audio

Output Level

Computer

Figure 12. Audio Gain and Attenuation

In Audio Setup mode, the input that is selected for adjustment is automatically tied to output 1. Connect a VU meter or an audio system to output 1 to measure or monitor the audio while you perform adjustments.

There are two ways to measure the audio level during audio setup:

•Monitor the input audio level indicator (Power LED) on the front panel.

•Connect a VU meter to output 1 and, if necessary, temporarily set the output 1 level to the consumer (-10 dBV) level (see the Audio output level SIS commands in the “Remote Operation” section).

The input audio gain or attenuation can be adjusted from the front panel or by using the Extron Matrix Switchers Control Program or the SIS.

1.Apply audio signals to all inputs to be adjusted.

2.Press and hold the Audio Setup (I/O) button until the Audio Setup LED lights. Release the Audio Setup button.

3.Press and release an input button to select an input. The selected input can be adjusted and is tied to output 1 for measurement or monitoring.

a.The Output 1 through Output 3 LEDs display the approximate audio gain or attenuation for the selected input. The +dB and –dB LEDs display the polarity (+ [gain] or – [attenuation]).

• Each Output 1 through Output 3 LED indicates a range of 6 dB when lit:

• Output 1	LED off = 0 dB to 5 dB		1	2	3
			0 – 5 db
• Output 1	LED lit = 6 dB to 11 dB	6	– 11 db
• Output 1 and 2 LED lit = 12 dB to 17 dB		12	– 17 db
			18 db

• Output 1 through Output 3 LEDs lit = 18 dB

•The +dB LED on indicates a positive (gain) level. The –dB LED on indicates a negative (attenuation) level. Both LEDs on indicate 0 dB.

MVX 44 / 48 / 84 / 88 VGA Matrix Switchers • Operation 23