Page 2 - RISK OF ELECTRIC SHOCK; IMPORTANT SAFETY PRECAUTIONS
2 CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DONOT REMOVE THE COVER. NO USER-SERVICEABLE PARTSINSIDE. REFER SERVICING TO QUALIFIED PERSONNEL. FCC INTERFERENCE STATEMENT NOTE: This equipment has been tested and found to comply with the limits for a class B digital device, pursuant to part15 of th...
Page 3 - TABLE OF CONTENTS
3 INTRODUCTION: CX168 Overview .......................................................................................4Front Panel Illustration .........................................................................................4Rear Panel Illustration .............................................
Page 4 - INTRODUCTION; FRONT PANEL
4 FRONT PANEL WITH SECURITY PLATE INTRODUCTION Congratulations on your purchase of the CX168 poweramplifier. To help you obtain the best results from yourpurchase, we encourage you to carefully review this manual.With information including connections, configuration andoperation, it offers many usef...
Page 5 - REAR PANEL
5 INTRODUCTION REAR PANEL DIMENSIONSAND MOUNTINGPOINTS
Page 6 - UNPACKING & RACK MOUNTING; Rack Mounting
6 INSTALLATION: UNPACKING & RACK MOUNTING Rack Mounting Supporting the Rear of the Amplifier What is Included Unless the amplifier is being installed in its final, fixedlocation, we strongly recommend supporting the rear of theamplifier. Supporting the rear of the amplifier is required for mobil...
Page 7 - COOLING & AC MAINS REQUIREMENTS; AC Mains Connection; Air flow in QSC amplifiers; Fan Cooling; The correct AC line voltage; Connect the AC line cord
7 INSTALLATION: COOLING & AC MAINS REQUIREMENTS AC Mains Connection Do not obstruct the front or rear air vents! Make sure that plenty of cool air can enterthe rack, especially if there are other units which exhaust hot air into it. Connecting to the wrong line voltage isdangerous and may damage...
Page 8 - SETTING THE MODE CONFIGURATION DIP SWITCHES; Setup; The channels are grouped as follows:
8 SETUP: SETTING THE MODE CONFIGURATION DIP SWITCHES Setup By using the mode switches and connecting to the amplifierproperly, the CX168 amplifier can be configured as a 1 to 8channel amplifier. This flexibility enables the CX168 to beused for most any multichannel application. The CX168 can be thou...
Page 9 - Modes
9 SETUP: SETTING THE MODE: STEREO, PARALLEL, OR BRIDGE Modes Stereo- Stereo mode supports two completely separate audio channels, usually referred to as ‘left’and ‘right’. Stereo configurations have two separateinput signals and two separate output signals. Parallel- Parallel mode applies one input ...
Page 10 - MODE SWITCHES: CLIP LIMITER AND LOW FREQUENCY FILTERS; Clip Limiter
10 SETUP: MODE SWITCHES: CLIP LIMITER AND LOW FREQUENCY FILTERS The CX168 amplifier has separate clip limiters for each ofthe 8 channels. These clip limiters respond only to actualamplifier clipping. Amplifier clipping generates internal errorsignals which cause the clip limiter to quickly reduce ga...
Page 11 - Frequency Response Curves; Low Frequency Filtering Tips:
11 SETUP: MODE SWITCHES: CLIP LIMITER AND LOW FREQUENCY FILTERS Frequency Response Curves Filter off Filter ON, 33 Hz. Filter ON, 70 Hz. Low Frequency Filtering Tips: The OFF position should be used only for subwoofer systems with rated frequency response below 33 Hz. or if low frequencyfiltering ...
Page 12 - INPUTS- Using the Terminal Block Inputs
12 Unbalanced inputs : Connect the conductors to the connector asshown. Make sure that the unusedside of the balanced input isconnected to ground, as shown. Terminal block: unbalanced connections Terminal block: balanced connections CONNECTIONS: INPUTS- Using the Terminal Block Inputs jumper shield ...
Page 13 - Using the DataPorts; How to Connect to the DataPort:; If the accessory attaches with a QSC DataPort cable
13 CONNECTIONS: INPUTS- Using the DataPorts If used, the DataPort must be connected to a QSC DataPort productusing a QSC DataPort cable. Do not use computer cables; they looksimilar but can cause operational problems with your amplifier and/orDataPort accessories. The CX168 amplifier is equipped wit...
Page 14 - OUTPUTS; BRIDGE MODE PRECAUTIONS:; Outputs; Use 8 ohm minimum impedance in bridged mode.
14 CONNECTIONS: OUTPUTS BRIDGE MODE PRECAUTIONS: Do not use 2 ohm or 4 ohm loads in bridge mode! 8ohms is the minimum impedance for bridge modeoperation. This mode puts a high demand on the amplifier and speaker. Excessive clipping may causeprotective muting or speaker damage. Ensure the speaker has...
Page 15 - USING THE TERMINAL BLOCK CONNECTORS; How to make connections to the terminal block:; Terminal Block Connections
15 CONNECTIONS: OUTPUTS- USING THE TERMINAL BLOCK CONNECTORS The output connections are made by attaching speakerwires to the 8-pin terminal block connectors. Once theseconnectors have been “populated” with the necessaryspeaker wire connections, plug the terminal blocks intotheir respective output j...
Page 16 - POWER SWITCH and GAIN CONTROLS; Power Switch
16 If the POWER LED fails to illuminate whenthe switch is in the ON position: The power switch is a rocker-type switch. It is located onthe left side of the front panel. To turn the amplifier on, pushin on the top of the switch. To turn the amplifier off, push inon the bottom of the switch. The gree...
Page 17 - LED INDICATORS; CLIP; Occasional illumination:; LED Indicators
17 OPERATION: LED INDICATORS 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 powerlevels may be norma...
Page 18 - Gain Controls; GAIN CONTROLS
18 Gain Controls Typical gain control showing attenuation levelmarkings and LED’s for the channel. Note thatthere is only one BRDG (bridge) and one PAR(parallel) indicator per channel pair. Location of gain controls on the front panel of the CX168 Typical channel-pair control and indicator group on ...
Page 19 - GAIN CONTROL SECURITY PLATE; Gain Control Security Plate
19 OPERATION: GAIN CONTROL SECURITY PLATE 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 platemakes it difficult for others to adjust the gain. This may be desirable in instances where the gai...
Page 20 - Using the DataPort; USING THE QSC DATAPORT CONNECTIONS; DataPort Connectors
20 QSC’s DataPort equipped amplifiers offer operators of largeraudio systems a high degree of system monitoring andoperation from remote locations. A system operator in asports complex might be located hundreds of yards (meters)from the actual amplifiers, making ‘normal’ control andmonitoring of the...
Page 21 - What Can I Connect to the DataPort?; General Guidelines to using the DataPorts on the CX168
21 What Can I Connect to the DataPort? OPERATION: USING THE QSC DATAPORT 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 specifi...
Page 22 - Four Room Stereo Feed; TYPICAL APPLICATION EXAMPLES
22 A simple application of the CX168 would be an installation with 4 rooms of coverage; each room to be provided with a stereoaudio feed. All speakers are 4 ohm or greater impedance and have a frequency response rated down to 45 Hz., making themsuitable for the 70 Hz. low frequency setting. Clip lim...
Page 24 - DESCRIPTION OF STEREO & PARALLEL OPERATING MODES; When to use STEREO input configuration:
24 Parallel Mode: Stereo Mode: NOTE: Ensure that the MODE SWITCHES are setto STEREO when feeding two separate signals tothe two channels. STEREO MODE OPERATION PARALLEL MODE OPERATION APPENDIX: DESCRIPTION OF STEREO & PARALLEL OPERATING MODES NOTE! In the following diagrams, channels 1 and 2 are...
Page 25 - DESCRIPTION OF BRIDGE OPERATING MODE; BRIDGE MODE OPERATION-; Normal Operating Levels; A Note on Sound Pressure Levels; Bridge Mode; If exposure is
25 APPENDIX: DESCRIPTION OF BRIDGE OPERATING MODE BRIDGE MODE OPERATION- Note that speaker connection for bridge mono mode isdifferent 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 i...
Page 26 - MULTIPLE SPEAKER LOADS IN SERIES
26 APPENDIX: MULTIPLE SPEAKER LOADS IN SERIES Series connection is where the same signal current flowsthrough each of the speaker loads. The signal goes into oneterminal of the first speaker and out its other terminal; then thesignal goes into one terminal of the next load, and so on. If anyof the s...
Page 27 - MULTIPLE SPEAKER LOADS IN PARALLEL
27 APPENDIX: MULTIPLE SPEAKER LOADS IN PARALLEL If each speaker load is connected across the same signal source(the output of the amplifier), then the loads are in parallel withone another. If one of the speakers fails in a parallel-connectedsystem branch, the remaining speakers will continue to ope...
Page 28 - INDICATION: CLIP LED FLASHING; NO SOUND; • INDICATION: POWER LED INDICATOR NOT ILLUMINATED
28 • INDICATION: 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. Trim off all loo...
Page 29 - PROBLEM: DISTORTED SOUND; PROBLEM: NO CHANNEL SEPARATION
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,...
Page 30 - SPECIFICATIONS
30 SPECIFICATIONS 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 c...
Page 32 - WARRANTY; WARRANTY INFORMATION & HOW TO CONTACT QSC
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 wor...
Page 33 - NOTES
