12
FRONT PANEL DESCRIPTION
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 HR624s to play just enough louder to sat-
isfy the client and to eliminate most of the
amplifier clipping.
Mute Switch
Use this switch to turn on or off the HR624
from the front. It works with the
POWER
MODE
switch on the rear panel in the
following way:
• If the
POWER MODE
switch on the rear
panel is set to
STANDBY
, the front panel
mute
switch has no effect. The power
LED remains off.
• If the
POWER MODE
switch is
ON
, the
front panel mute switch turns the HR624
on or returns it to
STANDBY
mode, as
indicated by the power
LED (the power
LED goes off when muted).
• If the
POWER MODE
switch is in the
AUTO ON
position, the front panel mute
switch turns the HR624 on as long as there
is a signal present.
OL (Overload) LED
This LED blinks when the overload protec-
tion circuit has been triggered.
• Occasional blinking of the
OL
LED indi-
cates that the loudest transients are
reaching the maximum drive capability of
the amplifiers. This is okay, although
distortion may be audible.
• Frequent or continuous blinking of the OL
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.
PROTECTION CIRCUITS
There are a number of protection mecha-
nisms designed into the HR624 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 HR624 by overdriving them
past the point of amplifier clipping. Such dam-
age is beyond the scope of the Warranty.
POWER
MODE
AUTO
ON
STANDBY
ON
