Protection Circuits; Overexcursion Protection; Thermal Protection; Integrated Magnetic Shielding - Mackie XR624 Owner's Manual

Protection Circuits

There are several mechanisms designed into XR series
studio monitors to safeguard the speakers and
amplifiers from inadvertent damage.
CAUTION: The protection circuits are
designed to prevent damage to the speakers
under reasonable and sensible conditions.
Should you choose to ignore the warning signs (i.e.,
excessive distortion), you can still damage the speakers
in XR series studio monitors by overdriving them. Such
damage is beyond the scope of the warranty.

Overexcursion Protection

A 12 dB/octave high-pass filter below port tuning
just prior to the low-frequency amplifier prevents very
low frequencies from being amplified. Excessive low-
frequency energy below the usable frequency range
can damage the woofer by causing it to "bottom out,"
also known as overexcursion, which is equivalent to a
mechanical form of clipping.

Thermal Protection

All amplifiers produce heat. XR series studio monitors
are designed to be efficient both electrically and
thermally.
• If for some reason the heatsink gets too hot, a thermal
switch activates and turns off the amplifier.
• When the heatsink cools down to a safe temperature,
the thermal switch resets and normal operation
resumes.
• If the heatsink temperature again gets too hot, the
shutdown process repeats. Should this happen, make
sure that airflow to the rear of the cabinet is not
restricted.

Overload Protection

• If you see the overload indicator [11] blinking more
than just occasionally, it's an indication that you should
reduce the signal level coming from your mixer or other
signal source.
• The blinking overload indicator means the driver
thermal overload protection has activated a compressor.
This reduces the input level to the amplifiers.
• The compressor was designed to protect the speakers
and its action is highly audible.
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XR SERIES MONITORS

Input Signal Wiring

We recommend using high-quality, shielded cables
to connect the signal source to the signal input jack
[4] on all XR series studio monitors. Two types of input
connectors are provided to interface with virtually any
application you may have:
• Balanced microphone cables work well with the XLR
input.
• Balanced TRS cables work well with the 1/4" input.
NOTE: 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!
CAUTION: Do not attempt to connect a speaker output
directly to the input of a XR series studio monitor!
Speaker levels are much higher than line levels and
can damage the input circuitry in the XR series studio
monitors.

Care and Cleaning

XR Series Studio Monitors will provide many years of
reliable service if you follow these guidelines.
• Avoid exposing the monitors to moisture.
• Avoid exposure to extreme cold (below freezing
temperatures).
• Use a dry cloth to clean the cabinets. Only do this when
the power is turned off.