QSC CX902 Specifications

29Application GuideCONTRACTOR AMPLIFIERS

9Better, more uniform coverage will result from spacing the loudspeakers at 1.5 times the ceiling-to-ear distance.In the lunchroom example, this would

10-10.0-8.0-6.0-4.02.04.06.08.00.510.012.014.016.018.020.00.1 10.2 10 1005 20 5020.0dBW (ref 1 watt)Power (Watts)-2.0from the distributed line. Use th

11EXAMPLEA loudspeaker (sensitivity: 94 dB @ 1W, 1 meter) in a busy office covers an area with an ambient noiselevel of 67 dBA, measured at a seated p

12To compensate for the insertion loss, add a corresponding percentage to the sum of the transformer power taps.For transformers with a 1 dB loss, add

13EXAMPLEYou have a 70-volt transformer with taps labeled 1, 2, 4, and 8 watts. What power points will thosetaps provide on a 25-volt line?The table s

14Ch. 1Ch. 2>2Ω >8Ω >4Ω>2Ω >8Ω >4ΩCX 302, CX 502,CX 702, & CX 902CX 602V CX 1202VCX 302, CX 502,CX 702, & CX 902CX 602V CX 1

15Green roomCh. 1Ch. 215W 15W15W20W 20W 25W10W 10W 20W 25W10W 20W20W25Ww/ L-pad20W10W 20W 10W20W10W 10W 20W25WLoadChargeLastCarga= 425W8Ω8ΩCenter clus

16Other design considerationsSpeaker transformer saturationSpeaker transformers tend to be fairly small and can vary widely in quality. Many arethus p

17Speaker wire lossA wire’s resistance is inversely proportional to the cross-sectional area of its conductor, but even the highest-quality copper wir

19AC current consumptionA major objective in the design of the CX Series amplifiers—even the higher-powered models—is to permittheir operation from re

1Table of ContentsDistributed line principles ...3Side

20eldI rewoP8/1)esionknip(rewoP3/1)esionknip(rewoPlluF)enis(daoL rh/UTB rh/lack rh/UTB rh/lack rh/UTB rh/lack rh/UTB rh/lack203XC8Ω 8+ Ω 00205565 5410

20eldI rewoP8/1)esionknip(rewoP3/1)esionknip(rewoPlluF)enis(daoL rh/UTB rh/lack rh/UTB rh/lack rh/UTB rh/lack rh/UTB rh/lack203XC8Ω 8+ Ω 00205565 5410

21CX302CX302Left: a CX amplifier without its security cover installed Right: a CX amplifier with its security cover installedSpecially designed for co

22Features• Barrier strip output connectors• Direct transformerless 70-volt outputs (“V” models)• Zero inrush current—won’t trip circuit breakers at t

23DataPort pin identification123456789101112131415To DataPortPin 2To DataPortPin 2To DataPortPin 2To DataPortPin 2(Amp chassis)open = operateclosed =

24Ch. 1 + outCh. 2 + outCh. 1 - outCh. 2 - outCOMCOM70V70V100V100VIT-42 schematicCX amplifierCX amplifierCX amplifierCX amplifierXC-32-waycrossoverXC-

25CX3021234567728Front panel1. Power switch2. Cooling vents3. Gain control (Channel 1)4.CLIP, -10 dB, -20 dB andSIGNAL indicator LEDs, bothchannels5.

26CX 302 CX 502 CX 702 CX 902 CX 1102OUTPUT POWER in watts20 Hz–20 kHz @ 0.03% THD8Ω per channel 200 300 425 550 70020 Hz–20 kHz @ 0.05% THD4Ω per cha

27CX 302V CX 602V CX 1202VOUTPUT POWER in watts20 Hz–20 kHz @ 0.05% THD@ 70V 200 400 800@ 8Ω per channel 550 700@ 4Ω per channel 1100EIA: 1 kHz @ 0.05

28Address & telephone informationAddress:QSC Audio Products, Inc.1675 MacArthur BoulevardCosta Mesa, CA 92626-1468 USATelephone Numbers:Main Numbe

2©Copyright 1996, 1999 QSC Audio Products, Inc. All rights reserved.QSControl is a trademark of QSC Audio Products, Inc.“QSC” and the QSC logo are reg

30www.qscaudio.com1675 MacArthur Boulevard Costa Mesa, California 92626 USA • PH: (714) 754-6175 FAX: (714) 754-6174“CX” and “PowerWave” are t

38COM4816COM10W5W2.5W1.2W70V4.5V888Amplifier70V0COMSPKR2W1W0.5WCOM4816COM10W5W2.5W1.2WCOM4816COM10W5W2.5W1.2WABCCX Series Application GuideWith the he

4as much as 28.3 volts, as determined by Ohm’s Law, while an amp thatdoes 200 watts into 8 ohms can put out 40.0 volts.This is where the true concept

51 A1 A1 A1 AAmp: 800 watts@ 0.08 ?Ω8W8W8W8W8Ω8v100 ASpkr 1Spkr 2Spkr 99Spkr 100Total load impedance 0.08≈ Ω“Natural” voltagesSome power amps d

6Designing the distributed sound systemThere are several main steps in designing a distributed sound system:• Determining loudspeaker coverage and pla

7CenterclusterUnder-balcony fillto be understood: this is the “what did he/shesay?” syndrome. In this example, DC is approxi-mately 15 meters.Not all

8One of the most common uses ofdistributed lines is to power ceilingspeakers in office, retail, and com-mercial buildings. With ceiling-mounted loudsp