Allen&Heath ML3000 USER GUIDE

Using LCRplus

The ML3000 LCRplus system extends signal
imaging beyond conventional LR and LCR panning
by allowing full 3 speaker balance and positioning
from each channel and group. This satisfies the
standard requirements of mono, stereo and
conventional LCR speaker systems as well as
providing a unique extended capability.

The MAIN MIX. This comprises 3 outputs: L (left),
R (right) and C (centre). How you use these
depends on the type of sound system you are
running. For example, you may use all for a 3
cluster LCR system, just L and R for a conventional
stereo system, or C only for a mono system.

PAN and BLEND. These are the two imaging
controls that let you position the sound anywhere in
the three output mix. For example, it could be
balanced in all three outputs, somewhere between
any two, or routed to just one. The controls have a
smooth response with 3dB centre attenuation to
ensure that the power is distributed evenly between
the speakers as you move the signal around.

MONO PA. To control a mono sound system using
a single master fader, set BLEND fully clockwise to
route all the channel signal to the C output. The LR
outputs are not used and PAN has no effect.

MONO PA

BLEND

CLR

PAN

RL

STEREO PA. To control a stereo sound system,
set BLEND fully anticlockwise to route the signal to
LR only. Use PAN to position the sound between
the speakers. The C output is not used.

LRC

STEREO + CENTRE FILL. A centre fill speaker is
used to reinforce the sound to the first few rows of
the audience when the L and R speakers are
positioned far apart. Start with BLEND fully
anticlockwise to set up the main LR mix. Then
gradually rotate BLEND clockwise to raise the
signal in the fill speaker as required. It should not
be necessary to adjust beyond the centre position
at which point equal signal is fed to all 3 outputs.
Beyond centre the LR signal would drop
significantly. Having LCRplus available on every
channel and group means that you can choose
which signals are reinforced, for example the back
stage mics rather than the front floats which would
feed back if routed to the fill.

STEREO+FILL

BLEND

CLR

PAN

RL

LRC

LCR PA. LCR systems are increasingly popular in
large installed or touring systems. They comprise
three main speaker stacks, left, centre and right to
provide better coverage of a large audience. In
some situations C is used only for sounds such as
vocals to lift them out of the mix making them more
intelligible, leaving backing instruments in the LR
speakers. In other situations individual sounds are
panned between the speakers according to source
position.

Adjust both BLEND and PAN to position each
sound exactly where you want it whether in one
speaker, between two, or blended across all three.
Use BLEND to balance between the LR and C
speakers. Use PAN to adjust the balance between
the L and R speakers. PAN does not affect the
level of the C output.

STEREO PA

BLEND

PAN

LRC

CLR

RL

BLEND

PAN

LCR

LRC

CLR

RL

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PAN L

L

BLEND

CLR

PAN

RL

LCR

PAN L to C

BLEND

CLR

PAN

RL

CR

Positioning the Sound. Use the PAN and BLEND
controls to position the sound within the LCR image.
It is possible to dynamically move the sound using
the two controls together but this is not a common
requirement in real world systems. For example,
dynamically panning an actor as he moves across a
theatre stage may be uncomfortable for the front
row listeners who hears the voice move from say
the left speaker upwards to the hung centre
speaker, and then back down to the right rather
than evenly across the stage. Static positioning is
more common in the theatre situation where the ear
adjusts to and accepts the source of the sound.

PAN C to R

BLEND

PAN

BLEND

PAN

PAN R

LCR

CLR

RL

L

CLR

RL

CR

PAN L. To position the sound at the left speaker
only set PAN fully left and BLEND to LR.

PAN L to C. To position the sound between the
left and centre speaker set PAN fully left and adjust
BLEND clockwise from LR to C.

PAN C to R. To position the sound between the
centre and right speaker set PAN fully right and
adjust BLEND anticlockwise from C back to LR.

PAN R. To position the sound at the right speaker
only set PAN fully right and BLEND to LR.

LR

BLEND

PAN

FOCUS LR to C

BLEND

PAN

BLEND C to LR

BLEND

PAN

BLEND LR to C

BLEND

PAN

L

CR

Focussing the Sound. Typically, a large music
venue or festival may use an LCR system with
vocals and key sounds such as kick and bass fed to

CLR

RL

L

CR

the main centre cluster and backing instruments fed
to the LR stacks. This helps the clarity and
intelligibility of these sounds.

Use BLEND to position each sound in the LR or C
speakers. You can dynamically bring a sound

CLR

RL

forward by panning it from LR to C. For example,
use this to improve the focus of a backing
instrument such as guitar for the duration of a lead
solo. Pan it back from C to LR again after the solo.

Blending the Sound between Speakers. In non-

LCR

ideal situations where the three speakers do not
cover all the audience evenly, a small portion of
centre cluster lead sounds such as vocals can be

CLR

blended into the LR stacks so improving coverage.
Similarly, LR sounds can be blended into the centre

RL

LCR

cluster.

Using the two controls you can adjust the balance
smoothly listening to the results and being able to
make small changes without the big jumps in

CLR

RL

volume associated with switched routing.

While you could use the matrix to balance groups of
sounds between the speakers, LCRplus lets you
balance the image independently for each sound.

ML3000 User Guide 27