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F. Surround Wiring Diagrams:
JBL strongly recommends that each surround loudspeaker be individually wired back to the projection
booth, and that any paralleling of loudspeaker loads be made at that location. In general, we recommend that no
more than a single pair of sound loudspeakers be paralleled for use with a single amplifier section. Thus the total
number of surround loudspeakers in a given installation, divided by four, will give the total number of stereo power
amplifiers that will be required for the entire complement of surround loudspeakers. This approach will also allow
utmost flexibility in re-allocating surround loudspeakers for all eventualities in future A-chain technology.
Since all of JBL’s surround models are nominally 8 ohms impedance, the parallel load of two of them will
of course produce a 4-ohm load. Amplifiers should then be chosen that can deliver twice the loudspeaker rated
power into 4 ohms, as compared with their 8-ohm ratings.
Be sure in surround amplifier specification:
1. That the amplifier will not be overdriven in normal operation, and
2. That the individual loudspeakers will receive a signal input within their power rating.
Typical stereo surround hookup is shown in Figure 37. A typical Surround EX hookup is shown in
Figure 38.
In every case, we recommend that all loudspeaker paralleling be done in the booth, with “home run” lines to the
individual surround loudspeakers.
Figure 36: Wiring diagrams for ScreenArray systems. 3632 biamped mode (A); 4632 biamped mode (B);
4632T and 3632T triamped mode (C).
