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 mod-
