QSC CX168 manual

1 User Manual CX168 8-Channel Installed Sound Professional Audio Amplifier TD-000095-00 rev .A *TD-000095-00*[...]

2 CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE THE COVER. NO USER-SERVICEABLE P ARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL. FCC INTERFERENCE ST A TEMENT NOTE: This equipment has been tested and found to comply with the limits for a class B digital device, pursuant to part 15 of the FCC rules. These limits are designed to pr[...]

3 INTRODUCTION: CX168 Overview .......................................................................................4 Front Panel Illustration .........................................................................................4 Rear Panel Illustration ........................................................................................5 [...]

4 FRONT PANEL WITH SECURITY PLA TE INTRODUCTION Congratulations on your purchase of the CX168 power amplifier . T o help you obtain the best results from your purchase, we encourage you to carefully review this manual. With information including connections, configuration and operation, it offers many useful guidelines. The CX168 provides a high le[...]

5 INTRODUCTION REAR PANEL DIMENSIONS AND MOUNTING POINTS[...]

6 INST ALLA TION: UNP ACKING & RACK MOUNTING Rack Mounting Supporting the Rear of the Amplifier What is Included Unless the amplifier is being installed in its final, fixed location, we strongly recommend supporting the rear of the amplifier . Supporting the rear of the amplifier is required for mobile and portable use. If the amplifier is to b[...]

7 INST ALLA TION: COOLING & AC MAINS REQUIREMENTS AC Mains Connection Do not obstruct the front or rear air vents! Make sure that plenty of cool air can enter the rack, especially if there are other units which exhaust hot air into it. Connecting to the wrong line voltage is dangerous and may damage the amplifier or constitute the risk of elect[...]

8 SETUP: SETTING THE MODE CONFIGURA TION DIP SWITCHES Setup By using the mode switches and connecting to the amplifier properly , the CX168 amplifier can be configured as a 1 to 8 channel amplifier . This flexibility enables the CX168 to be used for most any multichannel application. The CX168 can be thought of as four separate 2-channel amplifiers[...]

9 SETUP: SETTING THE MODE: STEREO, P ARALLEL, OR BRIDGE Modes Stereo- Stereo mode supports two completely separate audio channels, usually referred to as ‘left’ and ‘right’. Stereo configurations have two separate input signals and two separate output signals. Parallel- Parallel mode applies one input signal to both channels. Both inputs of[...]

10 SETUP: MODE SWITCHES: CLIP LIMITER AND LOW FREQUENCY FIL TERS The CX168 amplifier has separate clip limiters for each of the 8 channels. These clip limiters respond only to actual amplifier clipping. Amplifier clipping generates internal error signals which cause the clip limiter to quickly reduce gain and minimize the overdrive. T o preserve as[...]

11 SETUP: MODE SWITCHES: CLIP LIMITER AND LOW FREQUENCY FIL TERS Frequency Response Curves Filter off Filter ON, 33 Hz. Filter ON, 70 Hz. Low Frequency Filtering T ips:  The OFF position should be used only for subwoofer systems with rated frequency response below 33 Hz. or if low frequency filtering is provided by other devices.  Know the sp[...]

12 Unbalanced inputs : Connect the conductors to the connector as shown. Make sure that the unused side of the balanced input is connected to ground, as shown. T erminal block: unbal anced connections T erminal block: bal anced connections CONNECTIONS: INPUTS- Using the T erminal Block Inputs jumper shield T erminal Block Connectors: Each channel h[...]

13 CONNECTIONS: INPUTS- Using the DataPorts If used, the DataPort must be connected to a QSC DataPort product using a QSC DataPort cable. Do not use computer cables; they look similar but can cause operational problems with your amplifier and/or DataPort accessories. The CX168 amplifier is equipped with four QSC DataPort connections that may be use[...]

14 CONNECTIONS: OUTPUTS BRIDGE MODE PRECAUTIONS: Do not use 2 ohm or 4 ohm loads in bridge mode! 8 ohms is the minimum impedance for bridge mode operation. This mode puts a high demand on the amplifier and speaker . Excessive clipping may cause protective muting or speaker damage. Ensure the speaker has a sufficient power rating. Refer to the label[...]

15 CONNECTIONS: OUTPUTS- USING THE TERMINAL BLOCK CONNECTORS The output connections are made by attaching speaker wires to the 8-pin terminal block connectors. Once these connectors have been “ populated ” with the necessary speaker wire connections, plug the terminal blocks into their respective output jack. The output jacks are configured in [...]

16 If the POWER LED fails to illuminate when the switch is in the ON position: The power switch is a rocker -type switch. It is located on the left side of the front panel. T o turn the amplifier on, push in on the top of the switch. T o turn the amplifier off, push in on the bottom of the switch. The green power LED should light up when the switch[...]

17 OPERA TION: LED INDICA TORS CLIP : Each channel has a red ‘ clip ’ LED that illumi- nates when the channel clips. It is located to the upper - right of each channel ’ s gain control. Normal indication: illuminates briefly at extreme output power peaks. Occasional clipping at high power levels may be normal. At power -on, the clip LEDs may [...]

18 Gain Controls T ypical gain control showing attenuation level markings and LED’ s for the channel. Note that there is only one BRDG (bridge) and one P AR (parallel) indicator per channel pair . Location of gain controls on the front panel of the CX168 T ypical channel-pair control and indicator group on the CX168 OPERA TION: GAIN CONTROLS The [...]

19 OPERA TION: GAIN CONTROL SECURITY PLA TE Gain Control Security Plate After final gain adjustments have been made, the gain controls can be covered with a security plate. This easy-to-use security plate makes it difficult for others to adjust the gain. This may be desirable in instances where the gain controls should not be tampered with. T o ins[...]

20 QSC ’ s DataPort equipped amplifiers offer operators of larger audio systems a high degree of system monitoring and operation from remote locations. A system operator in a sports complex might be located hundreds of yards (meters) from the actual amplifiers, making ‘ normal ’ control and monitoring of the system difficult, at best. By inte[...]

21 What Can I Connect to the DataPort? OPERA TION: USING THE QSC DA T APORT CONNECTIONS General Guidelines to using the DataPorts on the CX168 1. Each channel pair ( Ch.1-2, Ch.3-4, Ch.5-6, and Ch.7-8) has its own dedicated DataPort connector that applies control and monitoring functions to its specific channel pair . 2. The DataPort for channels 1[...]

22 A simple application of the CX168 would be an installation with 4 rooms of coverage; each room to be provided with a stereo audio feed. All speakers are 4 ohm or greater impedance and have a frequency response rated down to 45 Hz., making them suitable for the 70 Hz. low frequency setting. Clip limiting will be used with these full-range speaker[...]

23 APPLICA TIONS: TYPICAL APPLICA TION EXAMPLES T ri-Amp’d Stereo Cabinets with Subwoofer Driven by Bridged Channel Pair (continued) Routing is a function of ‘ easiest wiring ’ order and is: LF Driver Left: Ch. 4 Mid Driver Left Ch. 3 HF Driver Left Ch. 2 HF Driver Right Ch. 1 Mid Driver Right Ch. 5 LF Driver Right Ch. 6 Subwoofer Bridge Ch. [...]

24 Parallel Mode: Stereo Mode: NOTE: Ensure that the MODE SWITCHES are set to STEREO when feeding two separate signals to the two channels. STEREO MODE OPERA TION P ARALLEL MODE OPERA TION APPENDIX: DESCRIPTION OF STEREO & P ARALLEL OPERA TING MODES NOTE! In the following diagrams, channels 1 and 2 are shown as examples only . Any channel pair [...]

25 APPENDIX: DESCRIPTION OF BRIDGE OPERA TING MODE BRIDGE MODE OPERA TION- Note that speaker connection for bridge mono mode is different than other modes. See section on Connections: Outputs for proper bridge mode output connections. Bridge mode combines both output channels into one output. This mode is for driving a single, high-power-rated load[...]

26 APPENDIX: MUL TIPLE SPEAKER LOADS IN SERIES Series connection is where the same signal current flows through each of the speaker loads. The signal goes into one terminal of the first speaker and out its other terminal; then the signal goes into one terminal of the next load, and so on. If any of the speakers in a series-connected branch of a sys[...]

27 APPENDIX: MUL TIPLE SPEAKER LOADS IN P ARALLEL If each speaker load is connected across the same signal source (the output of the amplifier), then the loads are in parallel with one another . If one of the speakers fails in a parallel-connected system branch, the remaining speakers will continue to operate. If all speaker loads are the same impe[...]

28 • INDICA TION: CLIP LED FLASHING • If the red clip indicator flashes when signal is applied, the amplifier output may be shorted. Check that the speaker cable connec- tions are tight and reliable at both ends. Check the speaker cables for stray strands or breaks in the insulation. T rim off all loose strands of wire and insulate any exposed [...]

29 PROBLEM: DISTORTED SOUND Magnetic field from power supplies in equipment can induce hum into cabling that is located in the field. If hum is a problem, try relocating cabling so that is away from power supplies, transformers and other magnetic field producing devices. TROUBLESHOOTING: DISTORTION, NO CHANNEL SEP ARA TION, HUM, HISS, FEEDBACK • [...]

30 SPECIFICA TIONS CX168 OUTPUT POWER in watts FTC: 8 ohms per channel (20 Hz.-20 kHz., 0.05% THD) 90 4 ohms per channel (20 Hz.-20 kHz., 0.1% THD) 130 EIA: 8 ohms (1 kHz, 0.1% THD, 1 channel driven) 120 (100 watts, all channels driven) 4 ohms (1 kHz, 0.1% THD, 1 channel driven) 180 (140 watts, all channels driven) Bridged Mono: 16 ohms, 20 Hz.-20 [...]

31 SPECIFICA TIONS CX168 AMPLIFIER PROTECTION Full short circuit, open circuit, thermal, ultrasonic and RF protection. Stable into reactive or mismatched loads. COOLING Continuously variable speed fan; back-to-front air flow through tunnel heat sink INDICATORS Front Panel: POWER LED (green), 8 each (1 per channel) SIGNAL (green) and CLIP (red) LEDs[...]

32 Disclaimer QSC Audio Products, Inc. is not liable for any damage to speakers, amplifiers, or any other equipment that is caused by negligence or improper installation and/or use of the ISA amplifier . Product Warranty QSC guarantees the CX168 amplifier to be free from defective material and/or workmanship for a period of three years from the dat[...]

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36 QSC Audio Products, Inc. 1675 MacArthur Boulevard Costa Mesa, California 92626 USA “ QSC ” and the QSC logo are registered with the U.S. Patent and T rademark Office. ©2000 QSC Audio Products, Inc.[...]