QSC Audio CX168 Stereo Amplifier User Manual
Contents
1. gt using the DataPort connection for audio input signals do not apply inputs to the terminal block input connectors If the DataPort connection is used only for monitoring amplifier operating conditions and NOT for providing audio inputs to the amplifier then the terminal block inputs OSC DataPort Cable may be used to supply the audio inputs to the amplifier How to Connect to the DataPort Direct mounting of DataPort accessories is NOT supported by the CX168 amplifier Devices that are normally mounted directly to the amplifier must be mounted remotely and connected to the DataPort using a DataPort cable This is due to the high density of connectors on an eight channel amplifier there is not enough space to allow for accessories to be mounted directly to the back of the amplifier If the accessory attaches with a QSC DataPort cable orient the HD 15 male plug correctly with the DataPort socket on the amplifier it is D shaped and will fit only way Push the plug onto the socket firmly and ensure it is seated properly Finger tighten the 2 retaining screws Do not over tighten Basic DataPort Notes 1 The amplifier Gain controls will need to be set at their anticipated high level setting Use reduced level set2. 10 Low Frequency Filtering Tips and CX168 Frequency Response 11 CONNECTIONS Inputs Connecting to the Input Terminal Block Inputs 12 Connecting to the DataPort 13 Outputs Connecting the Outputs in Stereo or in Bridge Mode 14 How to use the 8 pin Output 15 OPERATION PON 16 17 18 Plate Tor Galih CONOIS 19 HOC 20 Gmdelines TOF the 21 APPLICATIONS Four Room Stereo CU Tri Amplified Stereo Cabinets with 7 APPENDIX Detailed Explanation of Stereo Parallel and Bridge Operating Modes 24 M ltiple 5 Loads IM 5615 26 Multiple Speaker Loads 2 TROUBLESHOOTING 28 SPECIFICATIONS 30 WARRANTY INFORMATION a7 HOW CONTACT OSC AUDIO PRODUCTS 0 0 32 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 thi
3. TERMINAL BLOCK CONNECTORS Terminal Block Connectors Balanced inputs Connect the conductors to the connector as shown Unbalanced inputs Connect the conductors to the connector as shown Make sure that the unused side of the balanced input 1 connected to ground as shown jumper shield Terminal block unbalanced connections 12 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 DATAPORT CONNECTORS The CX168 amplifier is equipped with four QSC DataPort connections that may be used for connecting to accessory OSC DataPort devices th _ Each DataPort services a specific channel pair the channels are paired le as CH3 amp CH4 DATAPORT Ch 1 and Ch 2 Ch 3 and Ch 4 Ch 5 and Ch 6 Ch 7 and Ch 8 Each DataPort and its associated terminal block input pair can be configured independently there is no requirement to use a DataPort connection for all channels Only the Ch 1 Ch 2 DataPort can control the power supply standby mode The DataPort connection will supply the input signals to the amplifier If
4. BRIDGE PARALLEL BRIDGE PARALLEL installing the security plate C 19 OPERATION USING THE OSC DATAPORT CONNECTIONS DataPort Connectors 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 ina 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 integrating QSC s DataPort equipped amplifiers with OSC s DataPort accessories a dependable and robust control and monitoring solution can easily be implemented The DataPort is used for connection to optional QSC DataPort accessories DataPort accessory devices can provide remote cinema monitoring DSP filter and crossover functions A single DataPort is assigned to each channel pair Each DataPort is marked with the channel numbers served by that DataPort Note The DataPort connections on the CX168 offer full featured above that each DataPort is clearly labeled and is located be implementation of DataPort accessories and supply the tween its respective channel
5. CX168 8 Channel Installed Sound Professional Audio Amplitier User Manual 2 3 LIP POWER p 2 0 CHI C O __0 7 D oeme 7 oe 009067 0 9 SIGNAL CX16 PROFESSIONAL AMPLIFIER 20 SIGNAL e Os MODE je e eOe eOe MODE HORA Jec 9 5 aN 26 PAR 26 PRPS 26 PAR 7 wc 21 79 5 J e e N We oN 2 NAL 2 eapo 264 PAR TD 000095 00 rev A IMPORTANT SAFETY PRECAUTIONS amp EXPLANATION OF SYMBOLS CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN CAUTION REDUCE THE RISK OF ELECTRIC SHOCK DO NOT REMOVE THE COVER NO USER SERVICEABLE PARTS INSIDE REFER SERVICING 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 wit
6. OSC Audio Products Inc 1675 MacArthur Boulevard Costa Mesa California 92626 USA QSC and the QSC logo are registered with the U S Patent and Trademark Office 2000 OSC Audio Products Inc
7. 33 Hz FILTER 70 Hz FILTER MODE switch settings and speaker connection diagrams are printed on a rear panel label as shown above SETUP SETTING THE MODE STEREO PARALLEL OR BRIDGE Modes The following descriptions apply to a channel pair such as Ch 1 amp 2 or Ch 7 amp 8 It is possible to set each channel pair s mode differently and customize the system configuration All possible combinations will not be shown The following describes the behavior of one channel pair in the three modes of operation and the BRDG and PAR LED s Stereo Stereo mode supports two completely Stereo mode separate audio channels usually referred to as left switches 4 5 6 amp 7 down and right Stereo configurations have two separate CH7 MODE SWITCHES CH8 input signals and two separate output signals 27 0 CH 7 CH 8 mode switch shown O not illuminated out off Other channel pairs similar illuminated lit on Mode switch settings and LED indication for stereo mode operation BRDG and PAR indicators should not be illuminated when in stereo mode Parallel Parallel mode applies one input signal to Parallel mode CLIP both channels Both inputs of a channel pair are switches 4 5 6 up
8. 0 264 0 Ch 1 amp 2 Parallel Mode Indicator Ch 2 Gain Control FRONT PANEL WITH Ch 1 amp 2 Bridge Mode Indicator SECURITY PLATE PROFESSIONAL AMPLIFIER INTRODUCTION Input f REAR PANEL Output Connection amp Configuration Switch Configuration Switches Diagrams Cooling Air Inlet Vents a _ 9 6 k DataPort Output Serial Number Label ti Connectors IEC Power onnections DIMENSIONS AND MOUNTING POINTS handles shown INSTALLATION UNPACKING amp 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 Rack Mou
9. WEIGHT Front AC POWER switch 8 gain controls Back 4 DIP switch blocks with 10 poles 1 per channel pair Clip Limiters Stereo Parallel Bridge mode selection low frequency filter on off and frequency selection 19 0 48 3 cm wide 3 5 8 9 cm tall 2 rack spaces 14 35 6 cm deep from front mounting rails including rear support ears 21 pounds 9 5 kg net 27 pounds 12 3 kg shipping SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE 31 32 WARRANTY INFORMATION amp HOW TO CONTACT OSC WARRANTY USA only other countries see your dealer or distributor THREE YEAR WARRANTY 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 date of sale and will replace defective parts and repair malfunctioning products under this warranty when the defect occurs under normal installation and use provided the unit is returned to our factory via prepaid transportation with a copy of the proof of purchase i e sales receipt This warranty provides that examination of the returned product must indicate in our judgment a manufacturing defect This warranty does not extend to any product which has been subjected to misuse
10. 2 0 12 connected in parallel when the mode switch is set switch 7 down LY vo for parallel therefore connect only one input per CH 7 MODE SWITCHES ChE channel pair when in parallel mode The outputs are we cos connected the same as stereo mode Each speaker SHEER EEEE 27dB 0 2748 will be supplied the same signal which 1 still MN O not illuminated out off controlled by that channel s gain control CH 7 CH 8 mode switch shown illuminated lit on Other channel pairs similar Mode switch settings and LED indication for parallel mode operation PAR indicator should be illuminated and BRDG indicator should not be illuminated when in parallel mode Bridge Bridge mode combines the two channels of Bridge mode CLIP CLIP a pair such as Ch 3 amp Ch 4 into one higher CH7 CHE powered channel Like parallel mode both inputs of 109220007 1092205 7 siena a channel pair are connected in parallel when the CH7 MODE SWITCHES CHO 5 move mode switch is set for parallel therefore connect TTT o Jon lt Jo only one input per channel pair when in bridge SEEEREEEEE gt 7 PRIE gt 27 PAR mode There 4 possible channel pairs that can be bridged on the CX168 They are Ch 1 2 Bridge not illuminated out off
11. 3 ARALLEL MODE 45678910 CH3 AND CH4 cus ano cus BRIDGE MONO SWITCH SETTINGS 1234567 8 910 THE LOWER NUMBERED CHANNEL S INPUT AND GAIN CONTROL BRIDGEABLE CHANNEL PAIRS ND CH2 CH7 AND CH8 Stereo and Parallel Mode In stereo or parallel mode each speaker is connected to Its own individual channel of the amplifier This connection method is shown on the left side of the connection diagram rear panel or in the diagram right Use 4 ohm minimum impedance in stereo or parallel mode Ensure the mode configuration switches are set for stereo or parallel mode when connecting speakers to each channel s output Bridge Mode In bridge mode each speaker is connected to a bridged pair of outputs The channels must first be bridged by setting the mode configuration switches to the bridge settings Then con nect the speakers as shown on the right side of the connection diagram rear panel or in the diagram right Use 8 ohm minimum impedance bridged mode Ensure the mode configuration switches are set for bridge mode when connecting speakers to bridged output pairs BRIDGE MODE PRECAUTIONS Do not use 2 ohm or 4 ohm loads bridge mode 8 ohms is the minimum impedance for bridge mode A 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 pow
12. 6 and channels 7 amp 8 are set for bridge mode 11345 103 The channels are grouped as follows MODE SWITCHES Cho Channels 1 and 2 Channels 3 and 4 JUBUUUUEUE Channels 5 and 6 Channels 7 and 8 CH7 MODE SWITCHES CHO You can set the operating mode for each group by setting that group s configuration DIP switches in the desired 123 1 0 positions It is NOT POSSIBLE to group the channels differently For instance you can not bridge channels 3 amp 5 because they are not in the same channel group MODE configuration DIP switches are located on the rear panel and look like the illustration above Switch positions shown are for example only Set Before setting the configuration DIP switches you must first switches as required for your application decide how the amplifier will connect to the speaker system MODE SWITCH SETTINGS BRIDGE MONO CLIP LIMIT SWITCH SETTINGS 0N2 345678 90N WS E ee Oo INPUT SWITCHES AS SHOWN USE 1 45672810 THE LOWER NUMBERED CHANNEL S INPUT AND GAIN CONTROL il a il CONNECT SPEAKER AS SHOWN BRIDGEABLE CHANNEL PAIRS AND CH2 CH3 AND CH4 CH5 AND CH7 AND CH8 Hz FILTER ce FILTER ON __ FILTER OFF FILTER ON Hz FILTER
13. 220209 GD D OUTPUTS 15 16 OPERATION POWER SWITCH and GAIN CONTROLS Power Switch The power switch 1 a rocker type switch It is located on the left side of the front panel To turn the amplifier on push in on the top of the switch To turn the amplifier off push in on the bottom of the switch The green power LED should light up when the switch 18 in the on position When the power 1 switched off the LED may takes several seconds to go out this is normal If the POWER LED fails to illuminate when the switch is in the ON position 1 Check the AC cord and insure that both ends are fully inserted into their receptacles If the power LED still fails to illuminate 2 Check the AC outlet for voltage with a circuit tester or known good device lamp etc 3 Make sure that the amplifier is not in STANDBY mode If the amplifier is being controlled by one of its DataPort connectors the amplifier may be in standby mode Verify the AC power status from the DataPort device controlling the amplifier To turn the amplifier on push in on the top por tion of the rocker switch firmly It should move inward and snap into the position After switching on the power LED should illuminate To turn the amplifier off push in on the bottom portion of the rocker switch firmly It should move inward and snap into the position Afte
14. Ch 3 4 Bridge Ch 5 6 Bridge and Ch 7 8 Bridge CH7 CH8 mode switch shown r Any pair or number of pairs can be independently Other channel pairs similar illuminated lit on configured in bridge mode Use the first channel s input and gain control when bridge mode The second channel s gain control 1 non operative and should be turned all the way down Mode switch settings and LED indication for parallel mode operation BRDG indicator and PAR indicator should be illuminated when in bridge mode in parallel or bridge mode the unused input terminals may be used for daisy chaining the input signal to other channels of the CX168 or to other amplifiers For pictorial description of operating modes see Appendix 9 Note Do not connect more than one input per channel pair when operating parallel bridge mode However 10 Clip Limiter 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 preserve as much of the program dynamics as possible limiting occurs only during actual clipping Each channel s clip limiter can be switched on or off individually The clip limiter is internally set to respond as fast as possible after clipping is detected For program material that is primarily
15. OFF OFF ON 70 Hertz Bridged OFF OFF no effect in bridge Subwoofer Cabinet Ch 8 LF Filter no effect in bridge Channels 1 through 6 are configured for stereo mode because all channels completely separate from one another Channels 7 and 8 are bridged to combine their power to drive the subwoofer sub s are the most inefficient driver and therefore require the largest portion of the system power Clip limiters are used on the mid range drivers and the HF drivers because they are the most fragile and are damaged easily by clipping events The LF drivers and the sub s are rugged enough to handle even prolonged clipping events without damage and thus no clip limiting is used Low frequency filtering is used only on the LF drivers The HF and mid range drivers have filtering before the amplifier and need no filtering from the CX168 The subwoofer cabinet can handle the low frequencies without problem so no filtering for them The LF drivers response specification will dictate at what frequency 33 or 70 Hz the low frequency filter is set for 23 APPENDIX DESCRIPTION OF STEREO amp PARALLEL OPERATING MODES NOTE In the following diagrams channels 1 and 2 are shown as examples only Any channel pair can be configured as shown here The channels pairs on the CX168 are Channels 1 and 2 Channels 3 and 4 Channels 5 and 6 and Channels 7 and 8 Therefore in any example below replace channel 1 and 2 with the
16. channel pair numbers you are setting up Stereo Mode Each input signal is sent to its respective channel Each channel has independent low frequency subaudio filtering clip limiting gain control and output connection CH 1 input MODE switches set to STEREO When to use STEREO input configuration Use stereo mode for stereo sources L R inputs and any other situation that requires each channel to be completely separate from the other CH 2 input How to use STEREO mode 1 Set the MODE switches for stereo mode operation STEREO MODE OPERATION 2 Connect the two input signals to CH1 and to CH2 or NOTE Ensure that the MODE SWITCHES are set Signals may be provided from DataPort connection to STEREO when feeding two separate signals to the two channels 3 Connect the two speakers one to channel 1 s output terminals to channel 2 s output terminals Parallel Mode The channel 1 and channel 2 inputs are connected together applying a single input signal to both channels of the amplifier A signal into any input jack will drive both channels Each channel s low frequency filtering clip limiting and gain CH 1 input control still function independently Each channel drives its own speaker load MODE switches eos spi set for PARALLEL You can patch the input signal on to additional amplifiers daisy chain by using any of the remaining input jacks This feature eliminates
17. down the amplifier and fully illuminating the clip LED Illuminated most of the time Not normal for cleaner sound reduce the output of the amplifier and or input signal to avoid thermal shutdown of the amplifier and possible speaker damage If clipping persists at normal levels check for shorted or abnormal load impedances Fully illuminated on Amplifier is in thermal shut down Reduce gain settings or input signal and allow the amp to cool down Leave the power on so that the fan continues to run operation will automatically resume after the amplifier has cooled sufficiently 17 18 OPERATION GAIN CONTROLS Gain Controls The gain controls are located on the right side of the front panel They are operated by rotating the control clockwise to increase gain or counterclockwise to decrease gain When turned fully counterclockwise gain Is fully reduced and no output signal will be present When turned fully clockwise the voltage gain of the amplifier is 26dB and the output signal will potentially be full strength provided the input is fully driven The gain controls detented in 21 steps for repeatable adjustment Surrounding the Gain control the power attenuation level is shown in dB Each detent is approxi mately 1dB change in amplifier gain To operate the gain control rotate the control s knob so that the desired level is achieved A small flat tipped screw driver 1 blade size is typically used Be su
18. each channel to operate independently e Make sure other equipment in the signal path to the amplifier such as mixers preamps etc 1 set for stereo not mono PROBLEM HISS e Unplug the input cables to the amplifier If the hiss goes away then the problem is with the equipment or cables leading to the amplifier f the hiss is present with no audio input cables connected check that the AC line cord is properly grounded at its connection to the line If the ground connection is OK and the hiss continues with no input cables connected then the amplifier requires servicing e To keep the normal noise floor low operate the primary signal source at full level without clipping and avoid boosting the signal further between the source and the amplifier PROBLEM SQUEALS AND FEEDBACK e Microphone feedback should be controlled with mixer controls If noise continues to build up with zero mic gain there 1 a serious fault in the signal processors or cables Working in succession from the signal source towards the amplifier check each device in the signal path by reducing Its gain or unplugging PROBLEM HUM e Use acommon AC ground connection for all audio equipment Check the input cables for broken ground shield connection e Use balanced connections for the entire signal chain e The design of the amplifier eliminates internal hum fields but external transformers or other magnetic devices may cause hum Move cabling and
19. markings and LED s for the channel Note that there is only one BRDG bridge and one PAR parallel indicator per channel pair 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 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 install the security plate 3 Line up the tabs with the keyed portion of the ventilation slots insert into the slot and then slide the panel fully right locking it in the slot 1 Use a 9 64 or 3 5mm hex key to loosen the screw Do not remove just loosen sev eral turns oe 92 7 SEJ 00 Oe 2 Orient the panel as shown and slide the right end Make sure the LED s are visible then tighten the of the plate under the screw screw with the hex key Do not over tighten _ P O CH1 CH2 CH3 CH4 POWER cLIP CLIP signal sienaL SIGNAL SIGNAL When properly installed the security panel will still allow you monitor all the channel status LED s and power LED The amplifier front panel will look like the illustration right after
20. neglect accident improper installation or where the date code has been removed or defaced HOW TO CONTACT QSC AUDIO PRODUCTS Mailing address Adresse postale Postanschrift Direccion postal QSC Audio Products Inc 1675 MacArthur Boulevard Costa Mesa CA 92626 1468 USA Telephone Numbers Num ros de telephone Telefonnummern N meros de tel fono Main Number Num ro principal Hauptnummer N mero principal 714 754 6175 Sales Direct Line Ligne directe ventes Verkauf Direkt Linea directo ventas 714 957 7100 Sales amp Marketing Ventes amp marketing Verkauf u Marketing Ventas y marketing 800 854 4079 toll free in U S A only sans frais aux E U seulement zollfrei nur beim USA sin costo en EE UU solamente Customer Service Service a la client le Kundendienst Servicio a la clientela 714 957 7150 800 772 2834 toll free in U S A only sans frais aux E U seulement zollfrei nur beim USA sin costo en EE UU solamente Facsimile Numbers Num ros de t l copieur Telefaxnummern Numero de FAX Sales amp Marketing FAX T l copie ventes amp marketing Telefax der Verkauf u Marketing FAX ventas y marketing 714 754 6174 Customer Service FAX T l copie service la client le Kundendienst Telefax FAX servicio la clientela 714 754 6173 World Wide Web www gscaudio com E mail info qscaudio com service qscaudio com NOTES 34 NOTES
21. s terminal block connectors required accessory voltage to DataPort devices that require it CX168 amplifiers DO NOT support direct mounting of smaller accessories like the DSP 3 due to the high density of connectors on the rear panel but they may be connected via cables Using the DataPort CH1 amp CH2 DATAPORT Use OSC DataPort cable to connect the CX168 DataPorts to DataPort accessories Consult the documentation for recommended mounting and interconnect information Do not use terminal block connections for inputs when the DataPort is used as the input signal source If you do the signals from the DataPort and terminal block inputs will be mixed possibly with unexpected results O see the following section for general operating notes regarding the DataPorts on the CX168 OSC DataPort Cable Connect to the DataPort using a QSC DataPort cable Align the connector with the socket housing and insert fully Finger tighten the retaining screws OPERATION USING THE OSC DATAPORT CONNECTIONS What Can Connect to the DataPort Consult your QSC representative for up
22. signal sources to identify hot spots in the Magnetic field from power supplies in equipment can system then avoid those spots Cables with faulty shielding are a common entry point for hum Use top quality cabling Another common source of magnetic fields are wall warts or pluggable transformers keep input wiring away from them from power supplies transformers and other magnetic field producing devices induce hum into cabling that ts located in the field If hum ts a problem try relocating cabling so that is away 29 30 SPECIFICATIONS OUTPUT POWER in watts FTC 8 ohms per channel 20 Hz 20 kHz 0 05 THD 4 ohms per channel 20 Hz 20 kHz 0 1 THD FIA 8 ohms 1 kHz 0 1 THD 1 channel driven 4 ohms 1 kHz 0 1 THD 1 channel driven Bridged Mono 16 ohms 20 Hz 20 kHz 0 1 THD 8 ohms 20 Hz 20 kHz 0 1 THD DYNAMIC HEADROOM DISTORTION SMPTE IM Typical 20 Hz 20 kHz 10 dB below rated power Typical 1 kHz and below full rated power FREQUENCY RESPONSE DAMPING FACTOR SIGNAL to NOISE unweighted 20 Hz 20 kHz VOLTAGE GAIN gain control set to 0 dB attenuation INPUT SENSITIVITY for rated power into 8 ohms INPUT CLIPPING Vrms INPUT IMPEDANCE CX168 90 130 120 100 watts all channels driven 180 140 watts all channels driven 180 260 2 dB at 4 ohms Less than 0 02 Less than 0 05 Less than 0 02 0 0 3 0 dB 8 Hz to 50 kHz 0 2 dB 20 Hz 20 kHz gt 200 for
23. the need for Y cables CH 2 input 3 not used When to use PARALLEL input configuration Use parallel mode when you need one signal to drive both channels each channel having its own control gain clip limiter low frequency filter CH2 input connectors may be used to daisy chain the input signal to How to use PARALLEL mode additional amplifiers 1 Set the MODE switches for PARALLEL mode 2 Connect the one input signal to either channel s input PARALLEL MODE OPERATION connector he unused input may be used for daisy chaining the signal to another device or channel pair 3 Connect the two speakers to channel 1 s output terminals one to channel 2 output terminals APPENDIX DESCRIPTION OF BRIDGE OPERATING MODE Bridge Mode Bridge mode combines both output channels into one output This mode 1 for driving a single high power rated load with CH 1 input twice the normal voltage swing This results in about 4 times the peak power and about three times the sustained power of a single channel It is also common to call this bridge mono mode When to use BRIDGE mode Use BRIDGE mode when you need to deliver the power of two channels to a single 8 ohm MODE switches set to BRIDGE load such as a subwoofer Do not use less than 8 ohm loads CH2in put ws in bridge mode Refer to the CONNECTIONS section of this manual for details How to use BRIDGE mode 1 Se
24. 8 ohm load 5 kHz and below 107 dB 26 dB 20 X 1 35 Vrms 10 Vrms 22 dBu 10k ohms unbalanced 20k ohms balanced SPECIFICATIONS AMPLIFIER PROTECTION COOLING INDICATORS CONNECTORS LOAD PROTECTION OUTPUT CIRCUIT TYPE POWER REQUIREMENTS CURRENT CONSUMPTION 120 VAC typical both channels driven in Amperes Idle 1 8 power 8 ohms 1 8 power 4 ohms 1 3 power 8 ohms 1 3 power 4 ohms CX168 Full short circuit open circuit thermal ultrasonic and RF protection Stable into reactive or mismatched loads Continuously variable speed fan back to front air flow through tunnel heat sink Front Panel POWER LED green 8 each 1 per channel SIGNAL green and CLIP red LEDs 4 each 1 per channel pair BRDG LED yellow 4 each 1 per channel pair PAR LED orange Input 8 3 pin terminal block euro or Phoenix Output 2 8 pin detachable terminal block connectors Control amp Monitoring 4 OSC DataPort connectors Turn on turnoff muting AC coupling DC fault blocking Clip limiting AB B SEE SERIAL NUMBER LABEL ON REAR PANEL FOR THE SPECIFIED OPERATING VOLTAGE Configured at factory for either 100 120 or 230 VAC 50 60 Hz 0 6 6 2 9 4 9 2 14 2 NOTE 1 8 power is representative of current draw with typical music program material with occasional clipping Pink noise 1 3 power 15 representative of program material with severe clipping CONTROLS DIMENSIONS
25. ER LOADS IN PARALLEL Multiple Lo Z 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 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 impedance the total imped ance of a parallel connected system branch is the impedance of one speaker load divided by the number of loads in the branch example three 8 ohm loads in parallel 8 3 2 667 or roughly 2 7 ohms too low to use on the CX168 It is not recommended to connect speakers of different imped ances In parallel because power will be divided unequally between them If you are experienced with mixing and matching speaker loads of varying impedances no damage to the amplifier will result as long as the total impedance is within 4 to 16 ohms per channel dependant upon operating mode PARALLEL LO Z LOADS is the abbreviation for equivalent impedance and means the impedance at the two connection points Zeq 2 parallel loads all same impedance Zeq Most PA type speaker cabinets are provided with two or more input jacks that are wired in parallel If one cabinet is connected to the amplifier the load impedance is equal to the one cabinet s specified impedance If you attach another similar cabinet to the remaining jack of the first c
26. abinet the two cabinets now in parallel with each other and the impedance will be half of the one cabinet value Consult your speaker s documentation for connection details as there are many connection methods use Below are examples of parallel connections of 4 8 and 16 ohm speakers 2 and 4 ohm parallel loads are not usable because the parallel impedance of 4 ohm loads will always be 2 ohms or less this is too low an impedance for the CX168 amplifier 3 parallel loads all same impedance lt 77 4 parallel loads all same impedance 1 1 a TEETER DO NOT PARALLEL 2 OHM LOADS FOR USE WITH CX168 AMPLIFIERS Impedance of speakers Zeq DO NOT PARALLEL MORE THAN TWO 8 OHM LOADS FOR USE WITH CX168 AMPLIFIERS 16 DO NOT PARALLEL 4 OHM LOADS FOR USE WITH CX168 AMPLIFIERS DO NOT PARALLEL MORE THAN TWO 8 OHM LOADS FOR USE WITH CX168 AMPLIFIERS 53 ohms Zeg _ 4 ohms 1 14 4 t t 16 16 16 16 Note Impedance has a phase angle also This is typically neglected in basic speaker calculations Note 4 ohms is the minimum impedance for stereo or parallel modes 8 ohms is the minimum impedance for bridge mode 27 28 TROUBLESHOOTING No SOUND Problem NO SOUND e INDICATION POWER LED INDICATOR NOT ILLUMINATED Check both ends of the AC line cord for proper connection Both ends should be fully seated in their connectors Check that the AC outle
27. ain controls INDICATION SIGNAL LEDS RESPONDING TO SIGNAL LEVEL If the green signal LED indicators are lighting normally the fault is somewhere between the amplifier and the speakers Check the speaker wiring for breaks Check for proper connection at each end Try another speaker and cable if necessary If your system has multiple speakers connected in series any one speaker failure will cause all other speakers in the same series circuit to lose their signal 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 loose strands of wire and insulate any exposed wire with electrical tape All connections should be made with great care and all wire terminations should be carefully checked to ensure quality workmanship If the red clip indicator flashes when connecting the speaker cable between the and terminals then that speaker cable or speaker may be shorted Check the cable and the speaker INDICATION CLIP LEDS BRIGHT AND STEADY The amplifier is in protective muting Three seconds or so of muting is normal when the is turned on After power up muting the Clip LED s should go out Overheating will cause protective muting and the Clip LED to fully illuminate If the amp is overheated the fan
28. ange around 85 90 dB and a rock concert may approach 100 dB general rule of thumb is that if you need to shout to be heard the sound is in the range that can damage hearing some jobs in the entertainment industry involving loud noise from music carry high risk for hearing loss In the U S the maximum job noise exposure 15 regulated by law Both the length of exposure and the extent decibel level of exposure are considered If exposure is at or greater than the maximum exposure protective mea sures must be taken table at right is referenced from OSHA s Permissible Noise Exposure table G16 Duration of Exposure sound Level per day in Hours dBA slow response po J J OC w 65 105 25 26 APPENDIX MULTIPLE SPEAKER LOADS IN SERIES Multiple Lo Z Loads in Series Series connection is where the same signal current flows through each of the speaker loads The signal goes into one speaker cabinets are NOT wired for series connection ability consult your speaker s documentation for connection information 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 It is not recommended to connect speakers of different imped of the speakers a series connected branch of a system fails ances In series because power will be divided unequally the signal is prevented from flowing through any of the loads b
29. e 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 speakers Operating mode of all four channel pairs will be set to stereo because the audio inputs are stereo and a stereo result is desired in each room Input connections can vary too much to provide meaningful examples For this example assume that each Input has its own discrete signal provided at the terminal block input connectors Routing would make sense kept in room number order Room 1 Fed by channel pair 1 Ch 1 amp 2 Room 2 Fed by channel pair 2 Ch 3 amp 4 Room 3 Fed by channel pair 3 Ch 5 amp 6 Room 4 Fed by channel pair 4 Ch 7 amp 8 MODE switch configuration Ch 1 Ch 2 mode switch Clip Limiters ON Low Frequency Filter ON Low Frequency Setting 70 Hz Mode stereo Ch 3 Ch 4 mode switch Same as first mode switch Ch 5 Ch 6 mode switch same as first mode switch Ch 7 Ch 8 mode switch Same as first mode switch Room 1 Room 3 R Room 2 Room 4 OUTPUTS R pm Stereo Cabinets with Subwoofer Driven by Bridged Channel Pair next page Two discrete 3 way tri amp cabinets are to be connected to the CX168 along with an 8 ohm subwoofer cabinet The subwoofer will require the most amount of power and therefore will be driven b
30. e to use a strong shipping container with enough packing material to prevent the amplifier from being damaged transit A Matin Fasten ear to amplifier with screws Optional rear rack mounting ear attachment methods refer to the rear rack mounting ear kits documentation for details A Matin Ear is fastened to rack rails then amplifier is installed so its support notch is positioned on the support pin of the rear ear INSTALLATION COOLING amp AC MAINS REQUIREMENTS Fan Cooling z 7 The CX168 amplifier draws cool air into the rear of the lt J amplifier and exhausts hot air from the front This is done so 4 e WARM AMPLIFIER the equipment in the rack stays as cool as possible This oe a method of cooling gives the operator direct air tempera ture feedback at the front of the rack where it is the most OF lt lt 5 lt 7 REAR AMPLIFIER a OF AA convenient The front panel s temperature indicates how hard the amplifier is working lt 7 The fan varies speed automatically to maintain safe internal RACK 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 t
31. er rating 903999909 OUTPUTS Stereo or parallel connection single speaker shown con nected to amplifier channel 6 output Ensure that all speaker connections maintain proper polarity to to m OUTPUTS Bridge connection single speaker shown connected to am plifier channels 5 and 6 bridged with mode switch settings Ensure that all speaker connections maintain proper polar ity to to CONNECTIONS OUTPUTS USING THE TERMINAL BLOCK CONNECTORS OUTPUT TERMINAL SAFETY WARNING Do not touch output terminals while amplifier power is on Make all connections with amplifier turned off Risk of hazardous energy When selecting speaker cable wire always use the largest wire size and shortest length of wire practical for an installation Larger wire sizes and shorter lengths minimize power loss and degradation of damping factor Do not place speaker cables next to input wiring Wire Size 18 10 AWG 1 0 4 0 mm Strip Wire Terminal Block Connections 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 two discrete connectors One connec
32. etween them If you are experienced with mixing and matching sound Total impedance for series connections 1 the sum of each of the impedances in the chain see illustration below series connection schemes are usually used with raw speakers not often with speaker cabinets for wiring conve nience The exposed speaker connections make this method easy for small strings of speakers one area Most PA type SERIES LO Z LOADS Zeq is the abbreviation for equivalent impedance and means the impedance at the two connection points Zeq 2 series loads speaker loads of varying impedances no damage to the amplifier will result as long as the total impedance is within 4 to 16 ohms per stereo parallel channel or 8 to 16 ohms bridged Below are examples of series connections for 2 4 8 and 16 ohm speaker loads Series connections resulting in an impedance of 250 ohms or greater are not recommended e Z eq 3 series loads 4 series loads Formula Zeq 21 22 Zeq 21 22 23 Zeq 21 22 23 24 Zeq 2 2 4 ohms Zeq 2 2 2 6 ohms Zeq 2 2 2 2 8 ohms Impedance of speakers Zeq 4 4 8ohms 4 4 4 4 12 ohms 2 4 4 4 4 4 16 ohms 2 8 8 16 2 4 8 8 8 24 Zeq 8 8 8 8 32 ohms Note Impedance has phase angle also This is typically neglected in basic speaker calculations APPENDIX MULTIPLE SPEAK
33. full range the effect on the overall audio quality should be imperceptible We recommend using the clip limiters for almost all applications especially full range audio applications Clipping can cause high frequency artifacts to be output to the speakers potentially damaging fragile high frequency drivers For program material that 1 primarily low frequency nature low frequency or subwoofer drive this may be perceived as a rubbery effect on the audio If this is the case may be preferable to turn the clip limiters off and let the amplifier clip occasionally With robust low frequency drivers the occasional clipping should cause no problems Low Frequency Filter When driving speakers with limited low frequency response It is important to limit the low frequency response of the amplifier Doing so can result more usable bass response since the speaker is not being overloaded by very low frequencies can t handle Explanation Low frequency sound waves require much more speaker cone motion to produce the same apparent loudness as higher frequencies Properly designed speaker enclosures help the speaker to move more air with less motion using techniques like porting Such enclosures only benefit from porting down to a certain frequency Below this frequency the speaker is unloaded and is basically free to move around uncontrollably without producing much bass Limiting the frequency range of the low freq
34. he 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 CHS MODESWITCHES CH6 CH MODESWITCHES CHE ars yD Connect AC line cord by orienting the IEC plug correctly and pushing the plug firmly P into the IEC receptacle It should seat tightly It To AC mains can only 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 The correct AC line voltage is shown on the be dangerous and 1 not recommended 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 you amplifier If the use of an extension cord is required ensure that It is the shortest length possible and 1 at least Connecting to the wrong line voltage is dangerous and may damage the amplifier or constitute the risk of electric shock Verify the 14 AWG Ensure that all grounding cor
35. hin 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 all ISA amplifiers 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 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 swi
36. nting 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 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 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 sur
37. ormal indication illuminates briefly at extreme SIGNAL output power peaks Occasional clipping at high power 99 PAR levels may be normal At power on the clip LEDs may briefly flash during turn on muting Continuous operation at high power may trigger the thermal protection circuitry shutting down the amplifier and fully illuminating the clip LED Operation will resume after the amplifier has cooled down sufficiently If no indication Check AC power cord AC mains and that the DataPort is not being used to force the amplifier into Standby mode When power is switched off the LED may take several seconds to extinguish go out this is normal If no indication check gain settings input cables connections and audio source If audio source 1 extremely low signal strength signal LED may not illuminate this is normal but indicates that the input signal strength should be increased Occasional illumination normal for weak input signal strength Fully illuminated on normal If no indication normal if the amplifier is operated at nominal output levels If the input signal is weak it may not be capable of driving the amplifier into clipping even at full gain Occasional illumination Occasional clipping once briefly every few seconds when operation at high power levels does not indicate trouble Continuous Operation at high power may trigger the thermal protection circuitry shutting
38. 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 amplifiers 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 Power On LED Indicator Cooling Air Exhaust Vents GAIN CONTROL SECTION Ch 1 and 2 shown Ch 1 Gain Control 1 Clip Indicator e 92 BRDG 0 0 1 Signal Presence Indicator Ch 2 Clip Indicator az Ch 2 Signal Presence Indicator 24 gS Nw e ATTEN 264
39. r switching off the power LED should extinguish ATTEN 264 0 The POWER LED is located at the upper left of the gain controls section of the front panel It is green LED that illuminates when the power is turned on and the amplifier is properly connected to the correct AC source The power LED extin guishes when the power is turned off OPERATION LED INDICATORS LED Indicators The LED indicators provide basic operation information to the operator The nor mal indications of the LED s are shown below NOTE The BRDG and PAR mode indicator LED s are discussed page 9 POWER The power on indicator LED is located at the upper left of the gain control cluster It is green and POWER el illuminates when the power switch 1 set to the on position and AC power is present at the IEC cord 18 24 receptacle ATTEN 27 Normal indication at power on the LED will illumi nate SIGNAL Each channel has a green signal LED located to the right of its gain control The signal LED lights up when the Input signal is sufficiently strong Normal indication illuminates when the input signal is present and sufficiently strong 26 0 PAR CLIP Each channel has red clip LED that illumi nates when the channel clips It is located to the upper ae right of each channel s gain control 12 _7 N
40. re not to use large screwdrivers as It is possible to damage the gain control by applying excessive torque Gain controls are sensitive electronic components and should be treated with care Each channel pair s gain controls and indicator LED s are grouped together as shown right The channels are paired in the following manner 097 0 Channel Pair 1 Ch 1 Ch 2 Channel Pair 2 Ch 4 Channel Pair 3 Ch 5 Ch 6 Channel Pair 4 Ch 7 Ch 8 As detailed in the Setup section of this manual channels can only be paralleled and bridged within their channel pair Example Channel 3 can be bridged with channel 4 only it can not be bridged with any other channel The dB markings around the gain controls are attenuation They show attenuation from full gain At Odb attenuation the voltage gain of the amplifier is 26 If the gain control is set at the 7dB attenuation position then the voltage gain of the amplifier is 19dB 26dB 7 dB POWER 12 x8 aie IO 08 SIGNAL 25 e gt W 2 1 Ai ATTEN 26 8406 CH5 re CH7 06 ee 967 1 14 0 AN SIGNAL 180 M s o Dis MODE NUS W 0 ATTEN 26dB 0 6dB 0 an Location of gain controls on the front panel of the CX168 CLIP n aia Typical gain control showing attenuation level
41. rect AC line voltage by checking the tions are maintained specification printed on the serial number label on the rear panel NOTE Excessive length or inadequate gauge may result in short muting episodes if all channels are driven to full power SETUP SETTING THE MODE CONFIGURATION 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 lt 11 MODE SWITCHES CH2 The CX168 can be thought of as four separate 2 channel amplifiers on one chassis Each of the four amplifier SHUEBUUUUEHE sections may be operated in Stereo Parallel or Bridge mode independently of the others For example channels 1 amp 2 CH3 MODESWITCHES CH4 could be set for stereo operation while channels 3 amp 4 are set for parallel operation all while channels 5 amp
42. s 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 OSC s extensive experience in power amplifier development the CX168 15 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 PowerWave 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 Power Switch FRONT PANEL Alternatively these DataPorts facilitate connection of signal processing equipment such as OSC 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
43. t the MODE switches for bridge mode 2 Connect the one input signal to channel 1 or channel 2 Input 3 Connect the one speaker load to the bridge output terminals 4 For a bridged pair use the first channel s gain control clip limiter and filter The second channel s controls will have no effect 5 Turn the second channel s gain to zero gain Filters and limiter settings of second channel do not matter Normal Operating Levels BRIDGE MODE OPERATION Note that speaker connection for bridge mono mode 1 different than other modes See section on Connections Outputs for proper bridge mode output connections The amplifiers protective muting system guards against excessive internal temperatures With normal ventilation and loads the amplifier will handle any signal level including overdrive Lower load impedances and higher signal levels produce more internal heating Loads below 4 ohm loads may trigger thermal shutdown A Note on Sound Pressure Levels sound is heard as the ear converts vibration from sound waves into impulses in the nerves of the ear Sounds above 90 decibels particu larly if the sound is prolonged may cause such intense vibration that the inner ear is damaged 90 decibels is about the loudness of a large truck about 5 yards away A jackhammer emits sounds of about 120 dB from 3 feet away and a jet engine emits sound of about 130 dB from 100 feet away Motorcycles snowmobiles and similar engines r
44. t works by plugging in a Known good device or by testing with a voltmeter If too many amplifiers are used on one outlet the building s circuit breaker may trip and shut off power If this is the case unplug some of the amplifiers from the outlet reset the building s breaker and try again For the other amps use an outlet that is connected to another circuit breaker to distribute the load current If using the DataPort connections the channel 1 and 2 DataPort controls the power supply of the amplifier Check whether or not the DataPort accessory connected to the CX168 1 forcing the power supply into standby mode An amplifier which keeps tripping the AC circuit breaker may have a serious internal fault Turn it off remove AC power and have the amplifier serviced by a qualified technician INDICATION SIGNAL LED S NOT RESPONDING TO INPUT SIGNAL LEVEL NOT LIGHTING If the green power indicator LED is lit but the signal LEDs do not light up at all check the Make sure the signal source Is working and try another input cable Connect the source to another channel or amplifier to check that it is working If you are using the terminal block inputs be sure the connectors are fully inserted at both ends of all interconnecting cables If you are using the DataPort for your input signal ensure the DataPort cable is properly connected at both ends and that the device Supplying the audio signal to the DataPort is properly configured Check g
45. tching 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 2001 QSC Audio Products Inc 05 is a registered trademark of QSC Audio Products Inc OSC and the QSC logo are registered with the U S Patent and Trademark Office The Audio Precision logo 1 the property of Audio Precision Beaverton OR All trademarks are the property of their respective owners TABLE OF CONTENTS INTRODUCTION 4 OIG eV 4 PCa let ape MAS 5 OIG 5 INSTALLATION 6 6 Supporting the Rear of the 1 6 I AG Mains AL Power 7 SETUP Setting the Configuration MODE 8 Setting Operating Mode Stereo Parallel or 9 10 Low Frequency Subaudio Filter 0
46. ting during setup amp test 2 f using the DataPort for audio input signals control of the audio level will be accomplished with the DataPort accessory device to which the amp 1 connected 3 Control of the amplifier s AC power standby mode will only be possible via the Ch 1 2 DataPort The amplifiers POWER switch must be physically set to the ON position to use the standby control feature 4 The order in which the four DataPorts are connected to external devices makes no difference to the amplifier However the host controller to which the amplifier is connected will show the channels in the order that cables are connected 13 14 CONNECTIONS OUTPUTS Outputs Refer to the label on the rear panel of the amplifier for proper wiring connections The output connection for STEREO and PARALLEL modes is on the left side of the label while the output connection for BRIDGE mode is shown to the right side of the label Note Polarity changes from channel to channel and 1 different for bridge mode Be certain of polarity of connec tions before applying power Reversed polarity may degrade audio frequency response FILTERS OFF ILTER OFF Hz FILTER a 70 Hz FILTER 33 Hz FILTER 45672810 FILTER ON 4 FILTER OFF 12 FILTER 0 70 Hz FILTER MODE SWITCH SETTINGS CLIP LIMIT ON2 34567 8 9ON STEREO MODE 1234567 8 910 B il CONNECT SPEAKER AS SHOWN
47. to date accessory compatibility QSC has several DataPort based accessories available like the CM 16a Amplifier Controller amp Monitor DSP 3 Digital Signal Processing Module DSP 30 Digital Signal Processor XC 3 Crossover SF 3 Subwoofer Filter LF 3 Low Frequency Filter DCM Crossovers amp Monitors 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 and 2 has a special function on the CX168 It is the master DataPort for controlling AND reporting power supply status of the amplifier It is only possible to control and report the status of the power Supply using the Ch 1 amp Ch 2 DataPort 3 In order for the Ch 1 amp Ch 2 DataPort to control the power status of the amplifier the front panel power switch MUST be in the ON position If the power switch is in the off position the amplifier will not respond to any com mands sent to its Ch 1 amp Ch 2 DataPort 4 The DataPort connection can be used for amplifier status monitoring only using the terminal block inputs for Supplying input signals to the amplifier Ensure that the DataPort connection supplies NO INPUT SIGNAL when operating this fashion If signal is applied to both the DataPort and the terminal block input connector at the same time the signals
48. tor carries the connections for channels 1 through 4 The other channels 5 through 8 Each connector has 8 pins each of which connects to the speaker wire using a screw clamp Refer to the diagram right for the basic connection procedure Be sure that speaker polarity is maintained The locations of the and terminals on the amplifier is not the same for each channel Ensure that all wires are neatly terminated with no loose strands Do not strip the insulation back excessively Loose strands and exposed wire beyond the terminals may cause a short circuit and cause protective muting of the amplifier Once all the required connections have been made to the terminal block connectors they may be inserted into the OUTPUTS jack on the rear panel Orient the connector properly it only fits one way and push it in until it is fully seated the receptacle Note each connector 1 oriented so its wires face outwards How to make connections to the terminal block 1 Strip the wires approximately 0 28 7mm 2 Twist any loose strands of wire together 3 Loosen the appropriate retaining screw fully 4 Insert the stripped wire into the receptacle 5 Tighten the appropriate retaining screw to secure Loosen Screw Insert Wire Tighten DMD ODA lt CO gt A A 0 28 7 mm 2 gt
49. tz has no effect unless the filter is set to the ON position Frequency Response Curves O Q 0 5 0 5 1 1 5 2 5 3 5 oft Filter ON 70 Hz Filter ON 33 Hz 10 20 50 100 200 500 1k 2k 5k 10k 20k 50k 100k Frequency Hz 11 CONNECTIONS INPUTS Using the Terminal Block Inputs Each channel has an active balanced Euro style terminal block input jack These terminal blocks allow the input wiring to be terminated using simple hand tools and allows for quick reconfiguration when needed The input impedance is 20k ohm balanced or 10k ohm unbalanced Balanced connection is recommended for all audio inputs Balanced signals are less prone to AC hum and other electrical noise Unbalanced signals can be suitable for short cable runs The signal source s output impedance should be less than 600 ohms to avoid high frequency loss in long cables If the DataPort is being used for the input signal source the terminal block connections should not be used for inputs However they may be used for daisy chaining the DataPort input signal other channels or amplifiers The signal available from the terminal block input connections will be about 10 dB lower than the signal presented to the DataPort
50. uency content enables the speaker to behave the way It was designed to If frequencies lower than designed are Supplied to the speaker performance will degrade All low frequency filters will change the character of low frequency transients For best results the cabinet design speaker capabilities and program material must be taken into account when configuring low frequency filtering SETUP MODE SWITCHES CLIP LIMITER AND LOW FREQUENCY FILTERS Clip Limiter mode switches 1 amp 10 up ON switches 1 amp 10 down OFF Chi MODE SWITCHES CH 2 CH 1 CH 2 mode switch shown Other channel pairs similar Switch 1 operates the first channel s limiter switch 10 operates the second channel s limiter CAUTION Clip limiting reduces extreme overdrive peaks allowing a higher average signal level without distortion Increasing the gain with the clip limiter engaged until clipping 15 again audible can double the average output power Be careful not to exceed the power rating of the speakers Low Frequency Filter mode switch 3 switch 3 switch 8 switch 8 switch 2 switch 2 switch 9 switch 9 up first channel s filter OFF down first channel s filter ON up second channel s filter OFF down second channel s filter ON up first channel s filter frequency 1 33 Hz down first channels filter frequency is 70 Hz up second channels filter frequenc
51. will be running at full speed and the chassis will be very warm to the touch sound should resume within a minute as the amplifier cools to a safe operating temperature DO NOT TURN THE AMP OFF This would stop the fan from cooling the inside of the amplifier Instead reduce the input signal or amp gain setting and wait for the amp to resume operation automatically Check for proper ventilation If the fan isn t running at all the amplifier requires servicing TROUBLESHOOTING DISTORTION No CHANNEL SEPARATION HUM HISS FEEDBACK PROBLEM DISTORTED SOUND e INDICATION CLIP LED FLASHING e the red clip indicator flashes before the signal indicator does the load impedance is abnormally low or shorted Unplug each speaker one by one at the amplifier If the clip LED goes out when you disconnect a cable then that cable or speaker is shorted Try another cable and speaker to locate and or remove the fault e INDICATION CLIP INDICATOR NOT FLASHING e This could be caused by a faulty speaker or loose connection Check the wiring and try another speaker e The signal source may be clipping Keep the amplifier gain controls at least halfway up 10 dB or less so that the source does not have to be overdriven PROBLEM NO CHANNEL SEPARATION e Check the mode switch settings on the back of the amplifier If the mode switches are set for BRIDGE or PARALLEL mode there will be no channel separation The mode switches must be set for STEREO for
52. will be summed and amplified The result may be undesirable 5 If using the DataPort for supplying the audio input signals to the amplifier we don t recommend using the terminal block input connectors even if they are connected to non operating audio sources The DataPort and terminal block inputs are connected in parallel and isolated by about 20k ohms of resistance Even with this isolation it is possible that connection to other signal sources may significantly alter the input impedance at the DataPort This could affect output levels as connections are altered 6 If using the DataPort for supplying the audio input signals to the amplifier do not use the unused terminal block inputs for daisy chaining the DataPort signals to other channel pairs or other amplifiers The DataPort device Supplying the audio signal will not accurately report gain and levels will be effected 7 The heat sink temperatures of the CX168 are reported on the first channel of each channel pair s DataPort other words to monitor all four heat sink temperatures all four DataPorts must be connected to the monitoring device such as OSC s CM16a Temperatures will be reported on channels 1 3 5 and 7 21 22 APPLICATIONS TYPICAL APPLICATION EXAMPLES Four Room Stereo Feed 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 hav
53. y ts 33 Hz down second channel s filter frequency is 70 Hz CH1 MODESWITCHES CH2 CH 1 CH 2 mode switch shown Other channel pairs similar Switches 2 and 3 operate the first channel s filter switches 8 and 9 operate the second channel s filter SETUP MODE SWITCHES CLIP LIMITER AND LOW FREQUENCY FILTERS Low Frequency Filtering Tips 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 specification of the speaker cabinet you are driving Match the low frequency roll off setting to the specified low frequency capability of the speaker cabinet Do not drive the speaker with frequencies below its rating Unless you have low frequency filtering before the amplifier use the low frequency filter to protect your loudspeakers from cone over excursion caused by frequencies below the speaker s limits The 33 Hz rolloff is a good all purpose setting Turn the filter on by setting the appropriate DIP switch to ON position and select 33 Hz using its 33 70 Hz DIP switch This setting is good starting point for most large full range cabinets The 70 Hz is good setting to use with smaller compact speaker cabinets having limited bass capability Turn the filter ON and select the 70 Hz setting when using smaller cabinets The frequency selection 33 or 70 Her
54. y two channels bridged into one Its impedance meets the minimum requirement for bridged output All other drivers are 4 ohms or greater and meet the single channel minimum impedance requirement Each of the tri amp cabinets will be driven with three discrete channels totaling 6 channels The total required channel count is 8 the CX168 1 the perfect tool for the job APPLICATIONS TYPICAL APPLICATION EXAMPLES Tri 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 HF Driver Left Ch 2 High Frequency High Frequency HF Driver Right 1 Driver Driver Mid Driver Right Ch 5 LF Driver Right Ch 6 Subwoofer Bridge Ch 7 amp 8 MODE switch configuration Mid Range Mid Range Ch 1 Ch 2 Mode Stereo Ch 1 Clip Limiter ON Driver 1 Ch 1 LF Filter OFF 11518 Driver Ch 2 Clip Limiter ON Ch 2 LF filter OFF A Ch 3 Ch 4 Mode Stereo Ch 3 Clip Limiter Ch 3 LF Filter Low m Low Ch 4 Clip Limiter OFF Frequency 2 Le OUTPUTS Frequency Ch 4 LF filter Ch 4 LF frequency 70 Hertz Driver Driver Ch 5 Ch 6 Mode Stereo Ch 5 Clip Limiter ON Ch 5 LF Filter Ch 6 Clip Limiter Ch 6 LF filter Ch 6 LF frequency Ch 7 Ch 8 Mode Ch 7 Clip Limiter Ch 7 LF Filter Ch 8 Clip Limiter
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