Crown Audio XLS Series Connect to AC Mains, Protecting Your Speakers, Startup Procedure

XLS Series Power Amplifiers

2 Setup

2.7 Connect to AC Mains

Connect your amplifier to the AC mains power source (power outlet) with the supplied AC power cordset. First, connect the IEC end of the cordset to the IEC connector on the amplifier; then, plug the other end of the cordset to the AC mains.

WARNING: The third prong of this connector (ground) is an important safety feature. Do not attempt to disable this ground connec- tion by using an adapter or other methods.

Amplifiers don’t create energy. The AC mains volt- age and current must be sufficient to deliver the power you expect. You must operate your amplifier from an AC mains power source with not more than a 10% variation above or a 15% variation below the amplifier’s specified line voltage and within the specfied frequency requirements (indicated on the amplifier’s back panel label). If you are unsure of the output voltage of your AC mains, please consult your electrician.

2.8 Protecting Your Speakers

It's wise to avoid clipping the amplifier signal. Not only does clipping sound bad, it can damage high- frequency drivers. To prevent clipping, insert a lim- iter between your mixer output and amplifier input. That way, no matter how strong a signal your mixer produces, the amplifier will not clip. Set the limiter threshold so that mixer signals above 0 on the mixer meters do not quite drive the amplifier into clipping.

Also, avoid sending strong subsonic signals to the amplifier. High-level, low-frequency signals from breath pops or dropped microphones can blow out drivers. To prevent subsonic signals, insert a high- pass filter between mixer output and amplifier input (or between mixer and limiter). Alternatively, switch in highpass filters at your mixer. Set the filter to as high a frequency as possible that does not affect your program. For example, try 35 Hz for music and 75 Hz for speech. On each mixer input channel, set the filter frequency just below the lowest fundamen- tal frequency of that channel's instrument.

2.9 Startup Procedure

Use the following procedure when first turning on your amplifier:

1.Turn down the level of your audio source.

2.Turn down the level controls of the amplifier.

3.Turn on the “Power” switch. The Power indica- tor should glow.

4.Turn up the level of your audio source to an optimum level.

5.Turn up the Level controls on the amplifier until the desired loudness or power level is achieved.

6.Turn down the level of your audio source to its normal range.

If you ever need to make any wiring or installation changes, don’t forget to disconnect the power cord.

For help with determining your system’s optimum gain structure (signal levels) please refer to the Crown Amplifier Application Guide, available online at www.crownaudio.com.

page 10 Operation Manual