Owner
’s Manual
23
Owner’s Manual
Protection Circuitry
The DRM12A loudspeaker employs a built-in limiter
for less distortion at peak levels. Additional protection
includes automatic thermal shutdown should the amp
overheat. However, with Class-D amp technology, which
is highly-efficient, this should never be a problem.
The protection circuits are designed to
protect the loudspeakers under reasonable
and sensible conditions. Should you choose
to ignore the warning signs [e.g. excessive distortion],
you can still damage the speaker in the loudspeaker
by overdriving it past the point of amplifier clipping.
Such damage is beyond the scope of the warranty.
Limiting
The driver has its own compression circuit which
helps protect it from damaging transient peaks.
The compressor is designed to be transparent and
is not noticeable under normal operating conditions.
Overexcursion Protection
A subsonic filter circuit just prior to the power
amplifier prevents ultra-low frequencies from being
amplified. Excessive low-frequency energy can damage
the woofer by causing it to “bottom out,” also know
as overexcursion, which is equivalent to a mechanical
form of clipping.
Thermal Protection
All amplifiers produce heat. DRM12A loudspeakers
are designed to be efficient both electrically
and thermally. In the unlikely event of the amplifier
overheating, a built-in thermal switch will activate,
muting the signal.
When the amplifier has cooled down to a safe
operating temperature, the thermal switch resets
itself, and the DRM12A loudspeaker resumes normal
operation.
If the thermal switch activates, try turning down
the level control a notch or two on the mixing console
(or via the Speaker Control knob) to avoid overheating
the amplifier. Be aware that direct sunlight and/or
hot stage lights may be the culprit of an amplifier
overheating.
AC Power
Be sure the DRM12A loudspeaker 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 amplifiers place high
current demands on the AC line. The more power that
is available on the line, the louder the speakers 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 amplifiers.
Never remove the ground pin on the power
cord or any other component of the DRM12A
loudspeaker. This is very dangerous.
Care and Maintenance
Your DRM12A loudspeaker will provide many years
of reliable service if you follow these guidelines:
• Avoid exposing the loudspeakers 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 loudspeakers
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 cabinet,
particularly where the drivers are located.
