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XLS Series Power Amplifiers
page 11
Operation Manual
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.
2 Setup