Peavey CS 1200 User Manual

The purpose of a traditional high-level passive crossover found inside most speaker systems is to separate the low frequency material from
the program and feed it to the woofer (low frequency driver), and to separate the high frequency material from the program and feed it to the
tv/eeter (high frequency driver). This crossover is connected between a power amplifier and the speakers and, as its name implies, is made up
entirely of passive components (no transistors or tubes). Such a system is usually referred to as "full-range," which simply means that the
power amplifier must handle the full range of frequencies. There are many good reasons for using a biamplified professional system as
opposed to a full-range system. One reason is that the biamp system will provide more headroom with the same power amplifier complement
than that of the full-range system. The term headroom deserves some consideration Program material (music or speech) is made up of many
different frequencies and their harmonics. Most music, especially contemporary rock music, is bass heavy. That is, the low frequency
material contains much more energy than the high frequency material. If both high and low frequency material, such as voice and bass
guitar, are present in a full range system, the high-energy bass frequencies can use up mostof the poweravailablefrom the power amplifier,
leaving little (or none) for the high frequencies. The result can be severe clipping (distortion) of tho high frequency material. In abiamplified
system, the high frequency material is routed to its own power amplifier (and associated loudspeaker), which avoids tho clipping problem.
This results in an effective increase in system headroom that is greater than would be 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-1200 power amplifier patch panel and associated CS’" Series plug-in
active crossover modules.
Referring to Diagram 3, the jumper plugs in both crossover accessory sockets (12) have been replaced by two-way crossover modules.
Also notice that the PL-2transformer modules are still inthetransformer accessory sockets (10). This configuration now has the makings of
a complete stereo-balanced biamp system. The only thing required is an additional stereo power amplifier, which, together with the existing
dual power amp sections of the CS-12G0, makes up the four independent power amplifiers required for a stereo biamplification system. You
will notice that because of the pin out arrangements of the jumper plugs versus the crossover networks, whenever the jumper plugs are
removed from the crossover accessory sockets ( 12 ). the power amplifier in puts forthe respective channels are isolated (no longer connected
to anything) In other words, the crossover modules themselves and all associated connectors (as well as the PL-2 transformers and
respective XLR connectors) are islands unto themselves. In this case, two islands with each crossover having a balanced input (9), dual
(parallel) unbalanced inputs (11), an unbalanced low output (13). and an unbalanced high (14). In order to complete the system, external
patching must be accomplished between the low and high crossover outputs and the various poweramp inputs using shielded patch cords.
Reviewing our previous discussion concerning headroom, bass-heavy program material requires more power for the low frequency
system than the high frequency system. In general, high frequency horn drivers have lower power ratings (power handling capability), but
have high efficiency ratings (sound pressure capability for a given power) than do lowtrequencywoofers.Thus.it might be necessary to use
a smaller power amplifier on the high frequency components and a largor power amplifier on the low frequency components of a biamp
system. Such a system can be achieved using the CS-1200 stereo power amplifier itself for the two low frequency channels, and adding a
Peavey CS-800for the two high frequency channels. In thiscase, the low outs (13) of the crossover islands must be patched tothepower amp
inputs (15) of the CS-1200, and the high outs (14) of the crossover islands must be patched to the poweramp inputs of the CS-800. Four
shielded patch cords are required in this configuration. The stereo feeds from the associated mixing system will be patched into the balanced
XLR connectors (9) on the respective crossover islands. The system is then completed by connecting the proper speaker components to the
correct power amplifier outputs. A diagram is included at the end of this manual showing all connections. It is recommended that all
connections be completed and double-checked before applying power. Wrong connections could result in loudspeaker damage It is also
good practice to apply AC power to the power amplifiers with the sensitivity controls at full counter-clockwise settings (off) and then
gradually bring up tho levels to check connections and make sure at low sound pressure levels that the biamped system has proper routing of
highs and low 3 tothe respective amps, horns and bass enclosures. After completion of these tests, the various sensitivity controls should be
set to their normal operational settings (usually full clockwise).
Obviously, fora monaural biamp system (only one mixer feed), only one crossover module is required and only one crossover island will bo
used. In this case, onechannel of the CS-1200 can be patched forthe lows and the other channel patched forthe highs, resulting in a simple,
compact system with outstanding performance. Again, a word of caution is in order. Since the CS-1200 is capable of producing more than
600 watts RMS per channel into a 4 ohm load (or 300 watts each into two parallel 8 ohm loads; most horn drivers are 8 ohms), the high
frequency components of the particular loudspeaker system must be able to handle these power levels. Alternatives are to use a smaller
power amplifier forthe entire biamp system, such as the CS-800 or CS-400, which offer the same features as the CS-1200.
The Peavey DDT compression system adds a new dimension to biamped systems. Each power amplifier channel has its own Distortion
Detection Technique circuitry, and each is completely independent. When signal conditions exist which 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 which 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.
The Peavey CS-1200 offers maximum flexibility and performance features not found on most competitive units. By thoroughly
understanding the patch panel features, expansion to larger and more complex systems is only limited by the imagination of the user.
Toward this enc, v/e offer the following additional information which may or may not be obvious:
1. A biamp approach is only possible with loudspeaker systems which provide access to the individual speaker components,
bypassing the built-in passive crossover (most Peavey loudspeaker 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 which are specifically designed to
match the various loudspeakers in the 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 frequencies of 500. 800, and 1200 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 bo
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 CS series power amplifiers are
rated at4ohms. This means that the maximum number of components connected toany one particular poweramplifier channel
is two (two horns, two woofers). If additional components are required for additional coverage or projection, then additional
power amp channels are required.
4 The PL-2 Transformer module can be removed and the jumper reinstalled in any particular crossover island if a balanced input is
not desired or required for the crossover module. In this case, the associated XLR connector (9) is now unbalanced as per
previous discussion. If desired, the parallel unbalanced phone jack inputs (11) may be used to supply signal to the crossover
module. In addition, whenever the XLR connector on a particular crossover island is used (either balanced or unbalanced), the
crossover input jacks (11)can be used to patch out full range signals to other amplifier/speaker systems which are operating in
full range or other biamped systems which required different crossovers.

Peavey CS 1200 Specifications

General

Channels	2
Signal to Noise Ratio	> 100 dB
Input Impedance	20k ohms balanced, 10k ohms unbalanced
Weight	35 lbs
Dimensions	3.5" H x 19" W x 15.25" D