MACKIE 18" Powered Subwoofer HD 1801 - Manual (Page 14)

Placement
As mentioned in the previous two pages, HD1801
subwoofers may be flown. However, they are designed to
sit on the floor or stage, as well. A socket is
provided on top of the HD1801 for mounting other
Mackie loudspeakers. Use a suitable speaker mounting
pole to mount them on the HD1801. See the hookup
diagrams starting on page 4.
Check to make sure that the support surface (e.g.,
floor, etc.) has the necessary mechanical characteris-
tics to support the weight of the loudspeaker(s) and
subwoofer(s).
When pole-mounting loudspeakers, be sure that the
HD1801 subwoofers are stabilized and secured from
falling over or being accidentally pushed over. For
stacked scenarios, it is highly suggested that straps are
utilized. Failure to follow these precautions may result
in damage to the equipment, personal injury, or death.
As with any powered components, protect them from
moisture. Avoid installing the subwoofer in places
exposed to harsh weather conditions. If you are setting
them up outdoors, make sure they are under cover if you
expect rain.
Thermal Considerations
The HD1801 has a powerful built-in amplifier capable
of producing 800 watts of rms power. As an amplifier
works, it produces heat. The higher the signal level, the
louder and hotter it gets. It is important to dissipate the
heat as quickly as possible. This results in increased
reliability and longevity for the amplifier.
The amplifier module is cooled by twin
thermally-controlled vari-speed fans. In order for this
cooling system to work efficiently, it is important to
provide adequate airspace behind the subwoofer. When
positioning the HD1801, we recommend leaving at least
six inches of air space behind it.
In the unlikely event of the amplifier overheating, a
built-in thermal switch will activate, muting the
amplifier’s output. When the amplifier has cooled down
to a safe operating temperature, the thermal switch
resets itself, and the HD1801 resumes normal operation.
If the thermal switch activates frequently, try turning
down the level control a notch or two on the mixing
console (or the back of the HD1801) to avoid
overheating the amplifier. Be aware that direct sunlight
and/or hot stage lights may be the cause of an amplifier
overheating.
AC Power
Be sure the HD1801 is plugged into an outlet that
is able to supply the correct voltage specified for your
model. It will continue to operate at lower voltages, but
will not reach full power.
Be sure the electrical service can supply enough
amperage for all the components connected to it.
We recommend that a stiff (robust) supply of AC
power be used because the amplifier places high
current demands on the AC line. The more power that is
available on the line, the louder the subwoofer will play
and the more peak output power will be available for a
cleaner, punchier bass. A suspected problem of “poor
bass performance” is often caused by a weak AC supply
to the amplifier.
Never remove the ground pin on the power
cord or any other component of the HD1801.
This is very dangerous.
Care and Maintenance
Your Mackie subwoofers will provide many years of
reliable service if you follow these guidelines:
• Avoid exposing the subwoofers to moisture. If
they are set up outdoors, be sure they are under
cover if rain is expected.
• Avoid exposure to extreme cold (below
freezing temperatures). If you must operate the
subwoofers in a cold environment, warm up the
voice coils slowly by sending a low-level signal
through them for about 15 minutes prior to
high-power operation.
• Use a dry cloth to clean the cabinets. Only do
this when the power is turned off. Avoid getting
moisture into any of the openings of the cabi-
net, particularly where the driver is located.
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HD1801
HD1801