Overload Indicators; Maintenance - Genelec 1038CF Operating Manual

HEAVY WOODEN WALL
ABSORBING
MATERIAL
AMPLIFIER
REMOVED
FROM ENCLOSURE
VIBRATION
ISOLATORS
f ~ 2-8 Hz
Figure 3: Flush mounting the loudspeaker in
a wall constructed of wood
acoustical mass to properly implement a low
frequency radiation condition into half space
and be angled so that the loudspeakers are
correctly aimed. However, the loudspeak-
ers should not be mounted too high as this
increases the required vertical tilt of the loud-
speaker (maximum tilt angle < 20 degrees)
and reduces the optimum listening area.
Great care should be taken over how the
loudspeaker is mounted into the wall. Note
the following:
A space 50 to 100 mm (2 to 4") wide can
be left around the loudspeaker. Cover the
space around the loudspeaker with a facing
panel that should be fixed to the wall. Leave
a gap of about 5 to 10 mm (¼ to ½") between
the loudspeaker and the panel. Fill this gap
with a soft rubber gasket to allow for possible
enclosure movement (see Figure 6).
Ensure that the loudspeaker cables can
reach the rear of the loudspeaker enclo-
sures.
Regardless of the type of front wall con-
struction the loudspeaker enclosure should
be mounted on vibration isolators, with a
resonant frequency between 2 to 8 Hz, to
prevent vibrations from being transmitted to
the wall and impairing the low frequency per-
formance.
If a heavy wooden front wall construction is
used, the space around the enclosure should
be filled with absorbent mineral wool or foam
plastic. The wooden wall structure must be
CONCRETE WALL
SAND
BAGS
AMPLIFIER
REMOVED
FROM ENCLOSURE
VIBRATION
ISOLATORS
f ~ 2-8 Hz
Figure 4: Flush mounting the loudspeaker in
a wall constructed of concrete
heavily braced to achieve sufficiently high
mass and rigidity (see Figure 3).
In a solid wall (e.g. concrete) structure, the
space around the enclosure should be filled
with either absorbent mineral wool or sand
bags (see Figure 4).
The wall can also be constructed of a com-
bination of materials to achieve high acousti-
cal structural mass that will prevent low fre-
quency sound propagation and provide high
LF sound isolation (see Figure 5). Acoustic
consultants will be able to provide details and
design these structures.
Ensure that the enclosure is flush with the
surface of the wall. Discontinuities in the loud-
speaker mounting wall will cause diffraction,
which leads to inferior frequency response
and stereo imaging. So, if a decorative cloth
frame is used to cover the wall, make sure that
the edges adjacent to the loudspeaker are less
than 20 mm ( 3 / ") deep. The cloth must be very
4
thin Tricot or an acoustically transparent mate-
rial otherwise the high frequency response of
the system will be adversely affected.

Overload indicators

The loudspeaker is provided with two indica-
tor LED's marked 'CLIP PROTECT (FAULT)'
and 'READY'. The green LED indicates that
the loudspeaker is ready for use. The red
LED indicates that the amplifier is overloaded
or the driver protection circuit is activated. In
both cases reduce the signal level so that
MULTI-LAYERED WALL
(WOOD, CONCRETE,
BRICKS)
AMPLIFIER
REMOVED
FROM
ENCLOSURE
CONCRETE
STRUCTURE
VIBRATION
ISOLATORS
f ~ 2-8 Hz
Figure 5: Flush mounting the loudspeaker
in a wall constructed of a combination of
materials.
SPEAKER
RUBBER GASKET
(5-10 mm / ¼-½")
FACING PANEL
FIXED TO THE WALL
(50-100 mm / 2-4")
WALL
Figure 6: Covering the gap between the
wall and the loudspeaker enclosure.
the LED stops blinking. If the red LED stays
on constantly it indicates that the amplifier
thermal protection is activated. Let the ampli-
fier cool down and check that the ventilation
around the amplifier is not blocked. There
should be a clearance of more than 100 mm
(4") between the amplifier face panel and any
solid surface at the back.

Maintenance

No user serviceable parts are to be found
within the amplifier unit. Any maintenance or
repair should only be undertaken by quali-
fied service personnel. Ensure that if fuse
replacement is required, only fuses of the
same voltage and current rating are used.
Remember to disconnect the power supply
by removal of the mains cable, before fuse
replacement.