Installing Remote Amplifiers - Genelec Home Theater System Design And Installation Manual

Figure 8. Correct flush mounting of a
loudspeaker. Note the short distance to
the hard wall, use of damping material
and provision of amplifier ventilation.
This construction method is not what is referred to as the 'flush mounting' technique. For loudspeakers
to be acoustically flush mounted, they should be mounted into a solid and heavy wall structure which
limits the space that bass can spread into. Low frequency sound can then only travel in that limited
space. However, if the main loudspeakers are mounted so that their front baffles are 1.3 - 1.7 m (4 - 5
feet) away from the hard wall behind them, a back wall cancellation will occur (see 5.2 Wall Behind the
Loudspeaker Cancellations) in the 50 - 70 Hz region, thereby seriously compromising the low frequency
response of these loudspeakers. One solution is to choose cabinetry constructions that are not too deep,
for example, the loudspeaker is placed as close to the wall as possible thereby avoiding the effects of
the cancellation.
Also, when large front loudspeakers are positioned too close to the floor, their responses will have notches in
the 80 to 120 Hz frequency region, causing deterioration of the bass reproduction. Loudspeakers should be
placed at a reasonable height and if necessary slightly tilted down, which will minimise such floor reflections.
Avoid positioning the loudspeakers too high, >20 degrees, as this may become disturbing to listeners.
3.6

Installing Remote Amplifiers

In many Home Theater installations one needs to install the amplifier unit away from the loudspeaker
for ventilation and connection purposes. There are no cooling fans on these adapters so they can be
mounted inside the listening room and hidden so that the loudspeaker cable can be kept short.
Two types of Genelec rack adapters exist.
Rack Adapter (1037-412)
This model can be used for the HT210 / HT210B and HT312A models.
The kit contains one 7U rack mount chassis with internal cable and
connectors in place, one Speaker Cable Adapter and four 4 x 2 mm
screws. Note that the Speakon 8- and 4- pole cables between the loud-
speaker and the rack adapter are not included in this kit. They should
be ordered as a separate item.
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Figure 9. Incorrect flush mounting of a
loudspeaker. Unnecessarily long distance
to the hard wall and lack of damping mate-
rial will cause cancellation problems.