Rigging Hardware and Accessories
Rigging Mackie loudspeakers will invariably require
hardware not supplied by Mackie. Various types of load-
rated hardware are available from a variety of third-
party sources. There are a number of such companies
specializing in manufacturing hardware for, designing,
and installing rigging systems. Each one of these tasks
is a discipline in its own right. Because of the hazardous
nature of rigging work and the potential liability, engage
companies that specialize in these disciplines to do the
work required.
Mackie does offer certain accessory rigging items,
primarily for attachment to the hardware integral with
the loudspeaker. Some items, such as eyebolts, may be
used with a variety of products. While these accessories
are intended to facilitate installation, the wide variety of
possible installation conditions and array configurations
do not permit Mackie to determine their suitability or
load rating for any particular application.
Mackie is not in the business of providing complete
rigging systems, either as designers, manufacturers, or
installers. It is the responsibility of the installer to pro-
vide a properly engineered, load-certified rigging system
for supporting the loudspeaker from structure.
Rigging Notes
The HD1521’s intergral mounting points are designed
to support only the weight of their own loudspeaker
with suitable, external hardware. This means that each
HD loudspeaker must be supported independently of
any other HD loudspeaker and any other loads.
A minimum of two rigging points must be used to hang
an HD1521. More may be used for creating the desired
hanging angle as shown in the illustrations on page 8.
All mounting points are fully load bearing so any two
may be used for rigging; no mounting points are restrict-
ed to angle control only.
Thermal Considerations
The HD1521 has two powerful built-in amplifiers ca-
pable of producing a combined 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 mounted on a large heatsink,
which is cooled by convection where cool air is drawn
through its fins, carrying the heat away. In order for this
convection cooling to work efficiently, it is important
to provide adequate airspace behind the loudspeaker.
When positioning the HD1521, 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 sig-
nal and lighting the thermal LED. When the amplifier
has cooled down to a safe operating temperature, the
thermal switch resets itself, and the HD1521 resumes
normal operation.
If the thermal switch activates frequently, try turning
down the level control a notch or two on the mixing con-
sole (or the back of the HD1521) to avoid overheating
the amplifier. Be aware that direct sunlight and/or hot
stage lights may be the culprit of an amplifier overheat-
ing.
AC Power
Be sure the HD1521 is plugged into an outlet that
is able to supply the correct voltage specified for your
model. If the voltage should drop below 95% of the spec-
ified line voltage, the built-in amplifiers will no longer
be able to supply rated power. (They will continue to
operate down to 80% of the rated line voltage, but won’t
reach full power, resulting in lower headroom.)
Be sure the electrical service can supply enough am-
perage for all the components connected to it.
We recommend that a stiff (robust) supply of AC
power be used because the amplifiers place high cur-
rent 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 HD1521.
This is very dangerous.
Care and Maintenance
Your Mackie loudspeakers 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 loud-
speakers 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 cab-
inet, particularly where the drivers are located.
Owner’s Manual
Owner’
s Manual
