QSC Audio DCA Series user manual

APPLICATION EXAMPLE- Setting Up in the Cinema Sound System

Setting up the DCA Accessories in the Cinema Sound System

Setting up the DCA accessories in the B chain of the cinema sound system primarily involves setting the trim levels on the XC-3, LF-3, and SF-3. This requires the cinema processor’s internal pink noise generator and an acoustical real-time spectrum analyzer.

1.Set up the analyzer microphone in the center of the cinema audience seating area or in another recommended location.

2.Set the all DCA amplifiers’ gain controls to maximum.

3.Route the pink noise test signal from the cinema processor to the left channel XC- 3 input. Observe the frequency response on the spectrum analyzer and use the HF trim control on the XC-3 and the LF trim on the LF-3 to balance the levels of their frequency bands to that of the mid-frequency band, within specifications. If the shape of the HF response is not correct, use a boost setting that better corrects the deficiency; turn the amplifiers off before changing the switch settings.

4.Repeat this process for the center and right screen channels and any surround channels that are bi- or tri-amped.

5.Follow the processor instructions for setting sound pressure level outputs of all the channels, including the subwoofer.

If you are unable to obtain a satisfactory frequency response or SPL on a channel, carefully check the wiring and connections. Some likely causes are reversed speaker polarity on one or more drivers, loose or broken wiring or connections, or blown or damaged speaker drivers.

A typical 6.1 surround system with DCA amplifiers and LF-3, SF-3, and XF-3 cinema accessories

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