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Q osc/noise generator, Warning, Using the osc/noise generator – Allen&Heath ML5000 USER GUIDE User Manual

Page 50

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50

ML5000 User Guide

Q OSC/NOISE GENERATOR

WARNING

: The generator is capable

of producing a high level continuous signal. To
avoid damage to the speakers check that the
generator and output levels are turned down
before you route the test signal to the outputs.

Q1 OSC/NOISE TRIM. Adjusts the level of the

oscillator or noise signal from –30 to +10dB.

Q2 OSC/NOISE SELECT. In its up position pink

noise is selected as the generator source. Press to
select the 1kHz test tone.

Pink noise. This is a constant level random noise
signal with equal energy per octave covering the full
audio bandwidth.

1kHz Oscillator. This produces a pure 1kHz tone
(sine wave) for single frequency testing and line up.

Q3 OSC/NOISE TO TB. Press this switch to

route the pink noise or 1kHz tone test signal to any
combination of LR, C, Matrix and Grp/Aux outputs
that has their TB switches selected. The switch has
a latching action so that it can remain selected while
testing and calibrating the speakers.

Q4 DISABLE. Press the underpanel switch to

disable the osc/noise generator. This protects
against accidental operation during live
performance.

Using the Osc/Noise Generator

Start with the TRIM control Q1 turned down. Use
switch Q2 to select either pink noise or the 1kHz
tone as the test signal. Check all the TB enable
switches F5 G1 J4 S4 S5 are correctly set to
route the signal to the required outputs. Make sure
the DISABLE switch Q4 is up (flush with the
panel). Press OSC/NOISE TO TB Q3 to route
the signal to the selected outputs. Raise the TRIM
control and output faders to achieve the level
required. The test signal should register on the
console meters in the normal way.

Use pink noise to test the speakers for correct
operation. This is made up of the full audio
bandwidth and can test all the drivers at the same
time. Used with a reference microphone and RTA
(real time analyser) you can check the venue
acoustics for frequency response.

Use the 1kHz tone to check matching and line up
between equipment by adjusting input and output
levels using the meters as the reference.

When you have finished using the generator be
sure to disable it if you want to avoid the possibility
of accidental operation during performance.

max

min

TRIM

PINK NOISE

1kHz OSC

OSC/NOISE

TO TB

Disable

OSC/NOISE