3. INSTALLATION
3.1. Placement an Setup
In professional installations, QEM equalizers should be preferably placed in the same rack as
active filters (crossovers) and power amplifiers. In this case, it may be necessary to remove their rubber
feet.
In live P.A. applications where hosepipes between control (mixing desk) and stage are used,
QEMs should be placed near the mixing desk, thus easily allowing to perform adjustments by the
mixing engineer.
QEM equalizers have a very low power consumption, so they do not need any fan cooling;
nevertheless, you should avoid exposing them to extreme temperatures and you should try to place
them in a place as dry and dust-free as possible.
It is very important not to place them near noise sources, as transformers, dimmers, motors,
etc... and their power supply cables. Because of this same reason, under not any circumstance should
you remove the metal cover from the unit.
The QEM16-2 and QEM30-1 can be mounted in a 19" (482.6mm) standard rack, taking up
two unit heigth (88mm). The device is also provided with plastic washers for a clean and scratch-free
mounting, keeping the rack-mounting ears in good condition.
3.2. Connections
The QEM16-2 and QEM30-1 operates under voltages between 90 and 264 V at 47 to
63Hz. This device features an over dimensioned power supply that adapts to the mains voltage in
any country of the world with no need to make any adjustments. Make sure that the mains wire
(which plugs into 19) is far away from the signal cables in order to avoid any possible audio hum.
In order to protect the equalizer from eventual mains power overload or excessive power
consumption by the internal circuitry, there is a 500mA mains power fuse (18). If this fuse ever gets
blown up, you should replace it for an identical one. Should this new fuse also get blown up, please
contact our Technical Service as soon as possible. YOU MUST NOT EVER PLACE A HIGHER VALUE
FUSE.
The QEM16-2 and QEM30-1 units have XLR connectors for their inputs and outputs.
These models allow balanced and unbalanced connection. Balanced operation lowers
significantly cable noises. Here is the standard way of connection:
Balanced connection
Unbalanced connection
There are two main ways of connecting the QEMs:
1.- Between preamplifier and power amplifier.
Connect the preamplifier's or mixer's output to the equalizer's inputs (12,13,30) (marked
INPUT) and its outputs (14,15,31) (marked OUTPUT) to the power amplifier's inputs.
2.- Between SEND/RCV of any mixing unit (INSERT).
This kind of bridge can be found just before the general output MASTER fader, so this control
will not have any influence over the equalizer's operation.
The SEND output must be connected to the INPUTs of the QEM and its OUTPUTs to the
RCV input of the mixing unit.
1 Ground
2 Live or Direct signal
3 Cold or Inverted signal
1 Ground
2 Live or Direct signal
3 Ground
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