Front Panel Description; Mute Switch; Ol (Overload) Led; Protection Circuits - Mackie HR824 Owner's Manual

FRONT PANEL DESCRIPTION

Use this switch to turn on or off the HR626
from the front. It works with the POWER
MODE
following way:
• If the POWER MODE switch on the rear
ON
POWER
AUTO
MODE
ON
STANDBY
• If the POWER MODE switch is ON, the
• If the POWER MODE switch is in the
This LED blinks when the overload protec-
tion circuit has been triggered.
• Occasional blinking of the OL LED indi-
• Frequent or continuous blinking of the OL

PROTECTION CIRCUITS

There are a number of protection mecha-
nisms designed into the HR626 to safeguard
the loudspeakers from inadvertent damage.
CAUTION: The protection circuits are de-
signed to prevent damage to the loudspeakers
under reasonable and sensible conditions.
Should you choose to ignore the warning signs
(i.e., frequent Overload LED indications, ex-
cessive distortion), you can still damage the
speakers in the HR626 by overdriving them
past the point of amplifier clipping. Such dam-
age is beyond the scope of the Warranty.
12

Mute Switch

switch on the rear panel in the
panel is set to STANDBY, the front panel
mute switch has no effect. The power
LED remains off.
front panel mute switch turns the HR626
on or returns it to STANDBY mode, as
indicated by the power LED (the power
LED goes off when muted).
AUTO ON position, the front panel mute
switch turns the HR626 on as long as there
is a signal present.

OL (Overload) LED

cates that the loudest transients are
reaching the maximum drive capability of
the amplifiers. This is okay, although
distortion may be audible.
LED indicates that you have exceeded the
maximum drive allowed for the speakers.
The amplifiers are clipping, and the
overload protection circuit has taken over,
reducing the input level. You should reduce
the level from your signal source until the
OL LED blinks occasionally or not at all.

Overload Protect

• If you see the OL LED 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 OL LED indicates 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.
• The compressor was not designed for
mixing!
If a client insists on listening
to the monitors at a very
high volume, you may find
that the OL LED lights fre-
quently. Since the majority
of the power requirement in any monitor are
the low frequencies, selectively reducing the
low end can provide a little more headroom
and volume for the monitors. Change the LOW
FREQ FILTER switch to 80Hz if necessary,
to reduce the bass response. This may allow
the HR626s to play just enough louder to sat-
isfy the client and to eliminate most of the
amplifier clipping.
However, the best solution is to purchase
the companion HRS120 or HRS150 powered
subwoofer to reinforce the frequencies below
80Hz.