Stereo Input Channel - ALLEN & HEATH GL4000 User Manual

STEREO INPUT
The stereo channel has two independent input sections: XLR IN for mono
microphone or line input, and STEREO LINE IN on jacks for sources such
as stereo keyboards, voice modules and effects returns. When using the
channel as a mono XLR mic/line input the stereo line input can be
independently routed to L-R for a stereo effects return or additional line
input. The XLR inputs on adjacent channels can be patched into a stereo
line when using stereo or paired microphones.
XLR MIC/LINE INPUT - This section is the same as the mono channel
input except that it has only the XLR input for both mic or line. It uses the
same wide ranging balanced pre-amp stage and includes the swept lo-cut
filter and insert. Refer to the MONO INPUT section for a detailed
description of these controls.
STEREO LINE INPUT - The left/mono and right inputs feed a balanced
pre-amp stage with GAIN variable from fully off to +10dB boost. Press ØR
to reverse the phase of the right input signal to correct phase differences
between the inputs. the WIDTH control is normally set to the centre
detented position for normal stereo. Turn anticlockwise to narrow the
stereo image until it becomes mono. Continue anticlockwise to open up
the stereo image but with left and right reversed. Turning clockwise from
centre accentuates the stereo effect by producing a phase enhanced
"wide" image. Press PFL to listen to the stereo signal on headphones or
local monitor without affecting the main outputs.
DIRECT TO L-R routes the stereo line signal to L-R independent of the
main stereo channel which you may be using as a mic/line XLR input. The
GAIN control adjusts the level to L-R. PFL lets you check the post-gain,
post-width stereo signal independent of the main channel PFL.
XLR/STEREO selects the input source to the main stereo channel. When
pressed the stereo line input is selected, when released the XLR mic/line
input is selected.
EQUALISER - This provides separate, simultaneous stereo control of 4
frequency bands. Each band may be boosted or cut by up to +/- 15dB. HF
and LF have a shelving response and affect the high (treble) and low
(bass) frequencies respectively. MF1 and MF2 have a peak/dip (bell
shaped) response and affect the upper and lower mid frequencies
respectively. MF1 is centred on 2.5kHz (presence) and MF2 is centred on
250Hz (warmth). Careful use of the equaliser can go a long way to
brightening up the sound of your stereo instruments, or tuning out the
noise characteristic of many lower cost effects units.
AUXILIARY SENDS - 10 aux sends are provided. These work in the
same way as the mono channel. Note that the left and right signals are
combined as mono aux sends. No direct output facility is available.
ROUTING, PAN, METER and PFL - These are the same as on the mono
channel. When a stereo input is selected PAN acts as a balance control
to adjust the level of the left and right signals relative to each other. The
meter indicates the pre-fade left and right signals combined. PFL
operates in stereo so that you can hear the image of the stereo source and
check the relative levels on the L and R meters.
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