PROTECTION

A protection circuit is built into the C300z to protect the high-frequency compression driver from excessive power. When the power to the HF driver approaches the maximum, the power deliv ered to the driver is momentarily reduced. CAUTION: The protection circuit is designed to protect the HF driver under reasonable and sensible conditions. Should you choose to ignore the warn-

ing signs (i.e., frequent clip

LED indications, excessive distortion), you can still damage the speakers in the C300z by overdriving them past their recommended amplifier power-handling ratings, or past the point of ampli fier clipping. Such damage is beyond the scope of the warranty.

stops, and is characterized by a “flat-top” appear ance to the waveform when viewed on an oscilloscope.

Normal Sine Wave Signal ☺

Clipped Sine Wave Signal 

Amplifier Power

We give you three power-handling numbers for the C300z: rms (continuous), music, and peak. So how much power do you really need to drive the C300z?

The answer to that question depends on what type of program material you are running through the system and how loud it needs to be.

Some audio signals have lots of momentary peaks whose amplitudes extend far above the average overall level of the program. Percussion in- struments are a good example of this. Other types of signals, like highly compressed rock music, have a higher average signal level with fewer peaks. Speech reinforcement requires less power overall, but involves large moment-to-moment variations in level.

Assuming you want to use the full capability of the loudspeaker, and the program contains at least some momentary peaks, we recommend that you use an amplifier that is rated at twice the contin uous power rating of the loudspeaker (into 8 ohms). For the C300z, this would be 300 watts x 2

=600 watts per channel into 8 ohms. This insures that the amplifier can reproduce peaks that are 6 dB higher than the continuous (rms) power-handling rating before clipping occurs.

Preventing Loudspeaker Damage

Speaking of clipping, this is likely the number one cause of damage to loudspeakers. Clipping occurs when the signal at the output of any device in the system (not just the amplifier) reaches its maximum level. The input signal to the device may continue to increase, but the output simply

Clipping interrupts the motion of the transduc er, creating distortion and excessive heat in the driver, which can damage it over time.

Some folks think that if they use a power ampli fier whose power rating is below the maximum power-handling rating of the loudspeaker, then they can’t possibly damage the loudspeaker. But if the amplifier is driven into clipping, even a lower power amplifier can damage the loudspeaker.

The bottom line is that to prevent damage to the loudspeakers, you must have a properly operating sound system. Proper operation of a sound system includes being aware of the types of audio signals being reproduced, controlling the output levels accordingly, and operating all the devices in the system so that no clipping occurs within the signal chain.

RIGGING

The C300z cabinets are fitted with ten rigging points as shown in the diagram on the previous page. These are M10 inserts. M10 threaded eye- bolts (M10 x 1.5 mm x 20 mm) are available to fit in these inserts (PA-A1 Eyebolts). WARNING: Never attempt to suspend the C300z loudspeak- ers by their handles. If you

want to suspend them, use the

rigging points only. Consult a professional rigger or structural

engineer prior to suspending loudspeakers from a structure not intended for that use. Always know the working load limit of the structure supporting the loudspeaker array. Always make sure that the rigging hardware minimum rating is at least five times the actual load.

7