Peavey CS 1200X - Manual (Page 16)

The result usually is severe clipping (distortion) of the high-frequency material. In a biamplified
system, the high-frequency material is routed to its own power amplifier (and associated loud-
speaker), which avoids the clipping problem. This results in an effective increase in system
headroom that is greater than that which is obtained by simply using a second power amplifier/
speaker combination in full-range operation. To biamp, then, some type of active crossover is
employed in the mixer feed to separate the low- and high-frequency material, which is then
patched to separate power amplifiers to drive separate loudspeaker components. Such a system is
easily accomplished with the Peavey CS 1200X power amplifier patch panel and associated
CS Series plug-in active crossover modules.
The Peavey DDT compression system adds a totally new dimension to the typical biamped
system. Each power amplifier channel now has its own Distortion Detection Technique circuitry,
and each is completely independent. When signal conditions exist that could cause clipping in
the low-frequency power amp channel(s), the DDT system will simply limit that portion of the
total biamp system. This will in no way affect the high-frequency portion of the biamp system,
and it is free to increase in level until conditions exist that could cause clipping in that particular
power amp channel(s). At that point, the DDT system will limit the high-frequency portion of the
system. This is a very effective two-level compression system and will yield sound pressure
levels unmatched by conventional broad-band compression techniques.
BIAMP SYSTEM NOTES
1. A biamp configuration is only possible with loudspeaker systems that provide access to
the individual speaker components, bypassing the built-in passive crossover (most
Peavey systems offer biamp high and low switching jacks on the back panel).
2. The crossover module used must have the proper characteristics to match the particular
loudspeaker system. Of greatest importance is the crossover frequency. Peavey offers a
variety of plug-in crossover modules that are specifically designed to match the various
loudspeakers in the Peavey product line. These crossovers have the correct crossover
frequency, high-frequency pad, and equalization for the particular loudspeaker, resulting
in system performance with a very flat frequency response. Also available are general
purpose crossover modules at various frequencies from 100 to 5000 Hz for non-Peavey
loudspeaker systems.
3. The outputs of the crossover modules (both high and low) can drive several power amp
inputs. The parallel input jacks can be used to daisy-chain to additional power amps for
an expanded system on either the low- or high-frequency system (or both). Remember,
the components in most Peavey biampable speaker systems are 8 ohms. All Peavey
CSX Series power amplifiers are now rated at 2 ohms. This means that the allowable
maximum number of components connected to any one particular power amplifier chan-
nel is four (four horns, four woofers). If additional components are required in larger
systems, more power amp channels are needed. Often experienced sound technicians
limit the maximum number of components to three per power amp channel. This practice
allows the power amplifiers to run much cooler and creates a system that is less likely to
shut down thermally in a high-temperature environment!
4. The PL-2 transformer module can be removed and the jumper reinstalled in any particu-
lar crossover island if a balanced input is not desired or required for the crossover
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