FRONT PANEL DESCRIPTION

Power Switch

Use this switch to turn on or off the HR824 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
power switch has no effect. The PWR LED remains off.

•If the POWER MODE switch is ON, the front panel power switch turns the HR824 on or returns it to STANDBY mode, as indicated by the PWR LED.

•If the POWER MODE switch is in the AUTO ON position, the front panel power switch turns the HR824 on as long as there is a signal present.

OL (Overload) LED

This LED blinks when the amplifiers begin to clip and lights steadily if the overload protection circuithas been triggered.

•Occasional blinking of the OL LED indi- cates that the loudest transients are reaching the maximum output capability of the amplifiers. This is okay.

•Frequent or continuous blinking of the OL LED indicates that you have exceeded the maximum output capability of the amplifi- ers and that the amplifiers are clipping. If you persist, the overload protection circuit takes over, reducing the input level. You should reduce the level from your signal source until the OL LED blinks occasionally or not at all.

OL

PWR

ON

Overload Protect

The high and low frequency power amplifiers have clipping detectors that light the OL LED when either power amplifier output clips.

•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.

•If frequent clipping continues, the driver thermal overload protection activates a compressor that reduces the input level to the amplifiers. During this time the OL LED lights continuously.

•The compressor was designed to protect the speakers and its action is highly audible.

•The compressor was not designed for mixing!

PROTECTION CIRCUITS

There are a number of protection mechanisms designed into the HR824 to safeguard the loudspeakers from inadvertent damage.

CAUTION: The protection circuits are designed 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, excessive distortion), you can still damage the speakers in the HR824 by overdriving them past the point of amplifier clipping. Such damage is beyond the scope of the Warranty.

If a client insists on listening
to the monitors at a very high
volume, you may find that
the OL LED lights frequently. 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 switch to 47Hz or 80Hz, if necessary, to reduce the bass response. This may allow the HR824s to play just enough louder to satisfy the client and to eliminate most of the amplifier clipping.

12