Mackie HR824 Speaker User Manual


 
13
Thermal Protect
All amplifiers produce heat. The HR824 is
designed to be efficient both electrically and ther-
mally.
If for some reason the heatsinks get too hot,
a thermal switch activates, placing the
HR824 into Standby mode (indicated when
the red
PWR
LED turns off).
Should this happen, make sure that airflow
to the rear of the cabinet is not restricted.
When the heatsinks cool down to a safe
temperature, the switch resets and normal
operation resumes.
INTEGRATED MAGNETIC SHIELDING
The HR824 Studio Monitor contains drivers
with large magnet structures. The drivers’ mag-
nets are shielded to help prevent the magnetic
field from radiating out into the environment
and playing havoc with computer monitors or
TV screens. Unshielded speakers can cause
distortion in both the shape and color of the
picture if placed too close to a CRT (cathode
ray tube). If you have a particularly sensitive
computer monitor or TV screen, it may be nec-
essary to move the speakers a few inches away.
INPUT SIGNAL WIRING
You should use high-quality, shielded cable
to connect the signal source to the
SIGNAL
INPUT
jack on the HR824.
Foil shielded cables, such as Belden 8451,
8761, or 9501 are commonly used for studio
wiring.
Microphone cables work well.
The better the shield, the better the
immunity from externally induced noise
(like EMI and RFI). Route the cable away
from AC power cords and outlets. These are
common sources for hum in an audio
signal. Wall warts and line lumps are
especially insidious hum inducers!
You can purchase quality cables from your
Mackie dealer.
In certain home theater applications, it
may be necessary to connect the speaker
outputs from a stereo receiver to the inputs
of the HR824s, if the receiver doesn’t have
preamp outputs or other line-level output
connections.
CAUTION: Do not attempt
to connect a speaker output
directly to the input of the
HR824! Speaker levels are
much higher than line
levels and can damage the input circuitry
in the HR824.
You can, however, insert a speaker-level to
line-level signal attenuator between the
receiver’s speaker output and the HR824’s
input. Your Mackie dealer may be able to
help you find one, or you can build your
own. Contact our tech support department
for more information.