CX168 8-Channel Installed Sound Professional Audio Amplifier User Manual *TD-000095-00* TD-000095-00 rev.C 1 IMPORTANT SAFETY PRECAUTIONS & EXPLANATION OF SYMBOLS CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN CAUTION: TO REDUCE THE RISK OF ELECTRIC SHOCK, DO NOT REMOVE THE COVER. NO USER-SERVICEABLE PARTS INSIDE. REFER SERVICING TO QUALIFIED PERSONNEL. The lightning flash with arrowhead symbol within an equilateral triangle is intended to alert the user to the presence of uninsulated "dangerous" voltage within the product's enclosure that may be of sufficient magnitude to constitute a risk of electric shock to humans. The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in this manual. The lightning flashes printed next to the OUTPUT terminals of the CX168 amplifier are intended to alert the user to the risk of hazardous energy. Output connectors that could pose a risk are marked with the lightning flash. Do not touch output terminals while amplifier power is on. Make all connections with amplifier turned off. WARNING: TO PREVENT FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS EQUIPMENT TO RAIN OR MOISTURE. This amplifier has a serial number located on the rear panel. Please write this and the model number down and keep them for your records. Model: CX168 Serial Number:______________________________ Date of Purchase:____________________________ Purchased From:_____________________________ FCC INTERFERENCE STATEMENT 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 provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and if not installed and used in accordance to the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by switching the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures: - Reorient or relocate the receiving antenna. - Increase the separation between the equipment and the receiver. - Connect the equipment into an outlet on a circuit different from that to which the receiver is connected. - Consult the dealer or an experienced radio or TV technician for help. © Copyright 2002, QSC Audio Products, Inc. QSC® is a registered trademark of QSC Audio Products, Inc. "QSC" and the QSC logo are registered with the U.S. Patent and Trademark Office The Audio Precision logo is the property of Audio Precision, Beaverton OR All trademarks are the property of their respective owners. 2 TABLE OF CONTENTS INTRODUCTION: CX168 Overview .......................................................................................4 Front Panel Illustration .........................................................................................4 Rear Panel Illustration ........................................................................................5 Mounting Dimensions .........................................................................5 INSTALLATION: What is Included..............................................................................................6 Rack Mounting ....................................................................................6 Supporting the Rear of the Amplifier.....................................................6 Fan Cooling...........................................................................................7 AC Mains (AC Power) Connection..............................................................................7 SETUP: Setting the Configuration (MODE) Switches....................................................8 Setting Operating Mode (Stereo, Parallel, or Bridge)........................................9 Clip Limiter Setting.............................................................................10 Low Frequency (Subaudio) Filter Settings................................................................10 Low Frequency Filtering Tips and CX168 Frequency Response Curve...................11 CONNECTIONS: Inputs: Connecting to the Input Terminal Block Inputs ...................................12 Connecting to the DataPort Inputs.......................................................13 Outputs: Connecting the Outputs in Stereo or in Bridge Mode .........................14 How to use the 8-pin Output Connectors................................15 OPERATION: Power Switch ............................................................................................16 LED Indicators .......................................................................................17 Gain Controls ......................................................................................18 Security Plate for Gain Controls .........................................................19 DataPort Connector ...................................................................................20 DataPort Guidelines for the CX168.........................................21 APPLICATIONS: Four Room, Stereo Feed..............................................................................................22 Tri-Amplified, Stereo Cabinets with Subwoofer..............................................22 APPENDIX: Detailed Explanation of Stereo, Parallel, and Bridge Operating Modes..........24 Multiple Speaker Loads in Series........................................................26 Multiple Speaker Loads in Parallel........................................................27 TROUBLESHOOTING ........................................................................................................28 SPECIFICATIONS ......................................................................................................30 WARRANTY INFORMATION .............................................................................................32 HOW TO CONTACT QSC AUDIO PRODUCTS ............................................................................32 3 INTRODUCTION Congratulations on your purchase of the CX168 power amplifier. To 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 level of channel density in a small, lightweight form factor ideal for multi-zone audio systems. Representing the culmination of QSC's extensive experience in power amplifier development, the CX168 is a highly versatile, reliable, and user-friendly tool that will likely remain a central component of your system for years to come. Like the entire CX Series, the CX168 is equipped with QSC's exclusive PowerWaveTM switching power supply technology to virtually eliminate noise and hum while reducing the unit's overall weight. Comprehensive protection circuitry includes DC, infrasonic, thermal overload and short circuit protection. The CX168 includes 4 HD15 DataPorts (one per channel pair) for remote management or DSP. These ports allow each channel pair to be governed by QSControl, QSC's audio networking system--enabling the system operator to control amplifier gain levels, check the unit's clipping and thermal status, plus monitor numerous additional system parameters. Alternatively, these DataPorts facilitate connection of signal processing equipment, such as QSC's DSP-3, which offers two channels of independent digital signal processing - including crossover filters, shelf filters, signal delay, compression, peak limiting, and parametric filters. As individual channel pairs may be bridged, the CX168 is configurable as a 4-, 5-, 6-, 7-, or 8-channel unit. Further, the CX168 features detachable Phoenix-style input and output connectors--enabling the audio system to be wired with greater ease. Other features include 1-dB recessed and detented gain controls and a security cover for tamper-proof installations. The CX168 is easy to use. All operating mode switches are grouped together on the rear panel, with one switchblock per channel pair. These switches enable clip limiter on/off, LF filter on/off, LF filter select and operation modes. The amplifier's front panel includes corresponding LEDs to indicate Bridged or Parallel modes in addition to Signal and Clip status. Your CX168 power amplifier was designed to provide many years of trouble-free, great-sounding operation. We hope you enjoy your new CX168. FRONT PANEL FRONT PANEL WITH SECURITY PLATE 4 INTRODUCTION REAR PANEL DIMENSIONS AND MOUNTING POINTS 5 INSTALLATION: UNPACKING & RACK MOUNTING What is Included Your CX168 shipping container, as shipped from the factory, includes: - CX168 eight channel audio power amplifier - this user's manual - security cover (plate) for gain controls - self-adhesive rubber feet (use for non-rack mount applications) - eight 3-pin terminal block input connectors - two 8-pin terminal block output connectors - #14AWG IEC-type detachable power cord Save the container and packing material so the amplifier may be shipped without damage if service is ever required. If the original container is not available, be sure to use a strong shipping container with enough packing material to prevent the amplifier from being damaged in transit. Rack Mounting Use four screws and washers to secure the amplifier to the equipment rack rails. Support the weight of the amplifier while securing it to the rails to avoid bending or distorting the mounting ears. The amplifier may be used in an equipment rack or as a stand-alone unit. Rack mounting is optional. Self-adhesive rubber feet are provided for non-rack mount applications. Supporting the Rear of the Amplifier 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 be transported in any way, install the optional rear rack mounting ear kit to support the rear of the amplifier. During transport, the shock loads encountered on the chassis and rack can easily damage an unsupported amplifier and the rack rails. With proper support, reliability is enhanced. Rear rack mounting ear kits are an accessory item and are available from QSC's Technical Services Department or from your dealer or distributor. Refer to the literature included with the rack mounting ear kit for installation instructions. Two methods of rear rack mounting ear attachment are possible; use the method that best suits you application. Optional rear rack mounting ear attachment methodsrefer to the rear rack mounting ear kit's documentation for details 6 INSTALLATION: COOLING Fan Cooling & AC MAINS REQUIREMENTS The CX168 amplifier draws cool air into the rear of the amplifier and exhausts hot air from the front. This is done so the equipment in the rack stays as cool as possible. This method of cooling gives the operator "direct" air temperature feedback at the front of the rack, where it is the most convenient. The front panel's temperature indicates "how hard" the amplifier is working. The fan varies speed automatically to maintain safe internal temperatures and minimize noise. Keep the front and rear vents clear to allow full air flow. Air flow in QSC amplifiers 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. AC Mains Connection The correct AC line voltage is shown on the serial number label. Make sure the AC mains is the correct voltage. Connecting to the wrong line voltage is dangerous and may damage the amplifier. Connect the AC line cord by orienting the IEC plug correctly and pushing the plug firmly into the IEC receptacle. It should seat tightly. It can only be inserted when it is properly oriented. Use the cord supplied with the amplifier, or an equivalent. Insure that the wire gauge of the cord is #14AWG. Use of #16 or #18 AWG can be dangerous and is not recommended. The correct AC line voltage is shown on the serial number label. Use the best possible connection to the AC power source. Avoid extension cords as they will cause some voltage drop between the AC source and your amplifier. If the use of an extension cord is required, ensure that it is the shortest length possible and is at least #14 AWG. Ensure that all grounding connections are maintained. NOTE: Excessive length or inadequate gauge may result in short muting episodes if all channels are driven to full power. Connecting to the wrong line voltage is da ...