Extron electronic MLS 304SA, MLS 304MA, MLS 406 Making adjustments, Clipping level, Normal range

PRELIMINARY

Operation and Setup, cont’d

Making adjustments

Leave the bass and treble set to 0 and the loudness control set to off (default) before adjusting the input level (sensitivity). Audio input levels must be adjusted with an active audio signal.

1.Connect an active audio source to an input on the switcher.

2.Select the MLS input with the active input signal.

3.Adjust the switcher’s input level via the front panel or the control software until the desired output level is reached and/or the Mid/normal LED turns on or blinks.

NIncreasing the audio level beyond the point at which the Mid/normal LED blinks may result in a distorted output signal.

Front panel setup mode: press and hold the input button for 3 seconds; the input’s LED blinks. While still pressing the input button, rotate the Volume knob to adjust the input level.

NFor the MA and SA models, in setup mode a blinking or lit Mid/normal LED indicates that the power amplifier can deliver maximum power output.

MLS 304MA, MLS 304SA, MLS 406MA, MLS 406SA

	Clipping level
	•	Max LED blinks or lights: the audio input level is too high;
		audio will be distorted.
		Lower the input gain so that this LED does not turn on.
MAX	Normal range
	•	Mid LED blinks or lights: input level has been
MID
		properly adjusted. Adjust the input

MIN gain/attenuation until this LED blinks.

Signal detection threshold

•Min LED lights: a signal of at least -20 dBV (-18 dBu) (a low level consumer product level) is detected at the input.

NOTE If the Max/Clip LED lights, the audio may be clipped.

MLS 406

	Peak: a blinking LED indicates the level is set too high.
MAX	Normal: the specified output level (-10 dBV or +4 dBu)
MID	has been reached. A blinking LED indicates the level
MIN	is set properly for max. power output.
	Signal: when lit this indicates that a signal of at
	least -20 dBV (-18 dBu) is detected at the input.

4.Once the desired level is reached, release the input button, to save the audio settings.

5.Repeat steps 1 through 4 for each input.

6.Fine tune levels including bass, treble, and loudness once all output devices (speaker, amp, etc.) have been connected.

Loudness control automatically provides the correct amount of bass and treble required to compensate for the change in response of the human ear at low levels. As volume decreases, the MLS automatically boosts the signal at 100 Hz and

10 kHz. As volume is increased, the boost at those frequencies is decreased. By default loudness control is set to off. Use the control software to turn it on. See appendix A, Reference Material for a frequency response graph when loudness is turned on.

3-MLS 304 Series, MLS 406 Series • Operation and Setup