Meyer Sound M3D - Manual (Page 15)

Meyer Sound Laboratories Inc M3D™ Line Array • 9
Two variable-speed primary fans run continuously with
an inaudible operating noise of 22 dBA at 1 m at their
slowest speed. The primary fans begin increasing speed
when either of the two heatsinks reaches 42˚C. The fans
reach full speed at 62˚C and are barely audible near the
cabinet, even without an audio signal. In the event that
the heatsink temperature reaches 74˚C, the secondary
fans turn on and are clearly audible without an audio
signal. The secondary fans turn on in response to:
■ primary fan failure (check status immediately)
■ high source levels for a prolonged period
■ accumulation of dust along the cooling path
The secondary fans turn off when the temperature
decreases to 68˚C.
U SING AND R EPLACING THE R AIN H OOD
The rain hood installed on the M3D user panel is provided
to protect the loudspeaker’s electronics from direct
exposure to rainfall. Before using the M3D, open the rain
hood as described in the following procedure.
Opening the Rain Hood
1. Pull the exterior Velcro straps off the hood, allowing
it to open.
2. Lift the flap fully outward, and unfold the fabric rain
hood.
3. With your other hand, reach into the hood and free
the two PVC supports from their corner pockets in the
outer flap.
4. Fold both supports out and reinsert them into the two
pockets, shown in Figure 17, in the lower corners of
the soft side flaps. This will hold the rain hood fully
open for use, which is necessary for proper cooling of
the M3D electronics.
See Figure 18 for an example of an installed rain hood.
NOTE: In the highly unlikely event that the
secondary fans do not keep the temperature
below 85˚ C, the M3D automatically shuts down
until AC power is removed and reapplied. If the
M3D shuts down again after cooling and
reapplying AC power, contact Meyer Sound for
repair information.
Figure 17. Rain hood stiffener pockets
Figure 18. Fully open rain hood installed on a M3D
!
CAUTION: Always be sure the rain hood is
fully open when operating an M3D. Leaving the
hood partially open will limit the airflow
through the amplifier, which could cause it to
overheat and shut down.
pocket
1 ea. side
pocket
top stifener
FRONT