6

Fans and Cooling System

The SB-1 uses a forced-air cooling system with two fans
to prevent the amplifiers from overheating. A variable-speed
primary fan runs continuously with an inaudible operating
noise of 22 dBA at 1 m at its slowest speed. The speed of
the primary fan begins increasing when the temperature
of the heatsinks reaches 42°C. The fan reaches full
speed at 62°C and is barely audible near the cabinet,
even without an audio signal.
In the unusual event that the temperature reaches 74°C,
the secondary fan turns on and is clearly audible. The
secondary fan turns on in response to
• primary fan failure (check status immediately);
• high source levels for a prolonged period in hot
temperatures or direct sunlight;
• driver failure.
The secondary fan turns off when the temperature de-
creases to 68°C.
In the highly unlikely event that the secondary fan does
not keep the temperature below 85°C, the SB-1 auto-
matically shuts down until AC power is removed and
reapplied. If the SB-1 shuts down again after cooling and
reapplying AC power, contact Meyer Sound for repair
information.
The fans draw air in through ducts on the front of the
cabinet, over the heatsinks, and out the rear of the
cabinet. Since dust does not accumulate in the amplifier
circuitry, its life-span is increased significantly. Make
sure that the air ducts are clear and that there is at least
6 inches clearance for exhaust behind the cabinet.
A foam insert filter, in combination with the entire front grill
surface, acts as an air filter for the cooling system. Despite
the filtering, extensive use or a dusty operating environ-
ment can allow dust to accumulate along the path of the
airflow, preventing normal cooling. We recommend
periodically removing the grill, filter, and amplifier mod-
ule and using compressed air to clear dust from the
grill, filter, fans, and heatsinks.
Yoke Installation andRemoval

The floor method:

Lay two 2x4” boards, at least five feet in length, three feet
apart and cover them with a heavy blanket or carpet.
With the protective cover over the dish lie the SB-1
down on the boards so that the rigging points are
between the two boards and the amplifier is facing
upwards.