Troubleshooting Guide What might appear to be a malfunction in your unit may just be the result of slight misoperation or miswiring. Before calling service, first check the following table for possible problems. PROBLEM No sound. (No sound from one side.) (Blown fuse.) POSSIBLE CAUSE SOLUTION • Connect the input (or output) cables. • Check connections by referring to "Power indicator". • Replace the fuse and use lower volume. • After check the speaker cord and fixing the cause of the short, replace the fuse. • Input (or output) cables are disconnected. • Protection circuit may be activated. • Volume is too high. • The speaker cord is shorted. The output level is too small (or too large). The input sensitivity adjusting control is not set to the correct position. Adjust the control correctly referring to "Controls". The sound quality is bad. (The sound is distorted.) • The speakers wire are connected with wrong + / polarity. • A speaker wire is pinched by a screw in the car body. • Connect them properly checking the + / - of the terminals and wires well. • Connect the speaker wire again so that it is not pinched by anything. • Set switches properly by referring to "System examples". • The switches may be set improperly. KAC-849 KAC-749S 4-CHANNEL POWER AMPLIFIER INSTRUCTION MANUAL Specifications Specifications subject to change without notice. Audio Section .....................................................................KAC-849 Max Power Output (4 ½) 4 Channel Mode ...................................................................100 W ´ 4 3 Channel Mode...............................................100 W ´ 2 + 300 W ´ 1 2 Channel Mode ...................................................................300 W ´ 2 Rated Power Output (4 ½) 4 Channel Mode (20 Hz ~ 20 kHz, less than 0.08 % THD).....50 W ´ 4 4 Channel Mode (DIN45324, +B=14.4V) ................................50 W ´ 4 3 Channel Mode (20 Hz ~ 20 kHz, 0.08 % THD) + (1 kHz, 0.8 % THD) ...........................................................................50 W ´ 2 + 150 W ´ 1 2 Channel Mode (1 kHz, 0.8 % THD)....................................150 W ´ 2 Rated Power Output (2 ½) 4 Channel Mode (1 kHz, 0.8 % THD)......................................75 W ´ 4 Frequency Response (+0, –3 dB) ......................................5 Hz ~ 50 kHz Signal to Noise Ratio ....................................................................100 dB Sensitivity (MAX) (rated output).......................................................0.2 V Sensitivity (MIN) (rated output)........................................................5.0 V Input Impedance ............................................................................10 k½ Low Pass Filter Frequency (12 dB/oct.) (Variable) ................50 ~ 200 Hz High Pass Filter Frequency (12 dB/oct.) (Variable)................50 ~ 200 Hz Bass Boost Circuit (90 Hz) ................................................................6 dB KAC-749S 80 W ´ 4 80 W ´ 2 + 250 W ´ 1 250 W ´ 2 40 W ´ 4 40 W ´ 4 40 W ´ 2 + 120 W ´ 1 120 W ´ 2 60 W ´ 4 5 Hz ~ 50 kHz 100 dB 0.2 V 5.0 V 10 k½ 50 ~ 200 Hz 50 ~ 200 Hz 6 dB Take the time to read through this instruction manual. Familiarity with installation and operation procedures will help you obtain the best performance from your new power amplifier. For your records General..................................................................................KAC-849 KAC-749S Operating Voltage (11 ~ 16 V allowable) .......................................14.4 V Current Consumption (1 kHz, 10 % THD) ........................................31 A Dimensions (W ´ H ´ D) ...........................................261 ´ 57 ´ 256 mm ......................................................................(10-1/4´2-1/4´10-1/16 in.) Weight................................................................................3.5 kg (7.7 lb) 14.4 V 26 A 261 ´ 57 ´ 256 mm (10-1/4´2-1/4´10-1/16 in.) 3.5 kg (7.7 lb) Safety precautions 2WARNING To prevent injury or fire, take the following precautions: • When extending the ignition, battery, or ground wires, make sure to use automotive-grade wires or other wires with a 5mm2 (AWG10) or more to prevent wire deterioration and damage to the wire coating. • To prevent a short circuit, never put or leave any metallic objects (such as coins or metal tools) inside the unit. • If the unit starts to emit smoke or strange smells, turn off the power immediately and consult your Kenwood dealer. • Do not touch the unit during use because the surface of the unit becomes hot and may cause burns if touched. 2CAUTION To prevent damage to the machine, take the following precautions: • Be sure the unit is connected to a 12V DC power supply with a negative ground connection. • Do not open the top or bottom covers of the unit. • Do not install the unit in a spot exposed to direct sunlight or excessive heat or humidity. Also avoid places with too much dust or the possibility of water splashing. • When replacing a fuse, only use a new one with the prescribed rating. Using a fuse with the wrong rating may cause your unit to malfunction. • To prevent a short circuit when replacing a fuse, first disconnect the wiring harness. Record the serial number, found on the back of the unit, in the spaces designated on the warranty card, and in the space provided below. Refer to the model and serial numbers whenever you call upon your KENWOOD dealer for information or service on the product. Model KAC-849/749S Serial number © PRINTED IN USA B64-1969-00 (KM/EM) ■ Wiring • If a buzzing noise is heard from the speakers when the engine is running, connect a line noise filter (optional) to each of the battery wire. • Do not allow the wire to directly contact the edge of the iron plate by using Grommets. • Connect the ground wire to a metal part of the car chassis that acts as an electrical ground passing electricity to the battery‘s negative terminal. Do not turn the power on if the ground wire is not connected. • Be sure to attach a protective fuse into the battery wire close to the battery. Use a protective fuse having a capacity that is about 10 A higher than the maximum current drawn by the amplifier. • Use vehicle-type (fire-resistant) power supply wiring wire for the battery wire and the ground wire. The current capacity of the power supply wiring wire should be about 10 A higher than that of the protective fuse capacity (which means about 20 A higher than the maximum current drawn by the amplifier). • When more than one power amplifier are going to be used, use a power supply wiring wire and protective fuse of greater current-handling capacity than the total maximum current drawn by each amplifier. Example: One Power Amplifier Is Used Maximum Current Drawn Protective Fuse Cross-sectional Area of Wiring Wire (AWG) 31 A / 26 A 50 A ´ 1 [25 A ´ 2] 5 mm2 (AWG 10) or greater ´ 1 25 A 25 A 25 A 25 A NOTE • If you experience problems during installation, consult your Kenwood dealer. • If the unit does not seem to be working right, consult your Kenwood dealer. FCC WARNING This equipment may generate or use radio frequency energy. Changes or modifications to this equipment may cause harmful interference unless the modifications are expressly approved in the instruction manual. The user could lose the authority to operate this equipment if an unauthorized change or modification is made. ■ Cleaning the unit If the front panel gets dirty, turn off the power and wipe the panel with a dry silicon cloth or soft cloth. ■ Speaker Selection • The rated input power of the speakers that are going to be connected should be greater than the maximum output power (in Watts) of the amplifier. Use of speakers having input power ratings that are less than the output power of the amplifier will cause smoke to be emitted as well as damage. • The impedance of the speakers that are going to be connected should be 2½ or greater (for stereo connections), or 4½ or greater (for bridged connections). When more than one set of speakers are going to be used, calculate the combined impedance of the speakers and then connect suitable speakers to the amplifier. 4½ 2CAUTION Do not wipe the panel with a hard cloth or a cloth dampened by volatile solvents such as paint thinner and alcohol. They can scratch the surface of the panel and/or cause the indicator letters to peel off. 4½ 4½ 8½ 2½ 4½ Installation procedure 1. Remove the ignition key and disconnect the negative - terminal of the battery to prevent short circuits. 2. Set the unit according to the intended usage. 3. Connect the input and output cables of the units. 4. Connect the speaker wires. 5. Connect the power wire, power control wire and grounding wire following this order. 6. Install the unit in the car. 7. Connect the negative - terminal of the battery. 2WARNING To prevent fire caused by a short in the wiring, connect a fusible link or breaker nearby the battery’s positive terminal. 2CAUTION • Be sure to turn the power off before changing the setting of any switch. • If the fuse blows, check wires for shorts, then replace the fuse with one of the same rating. • Check that no unconnected cables or connectors are touching the car body. Do not remove caps from unconnected cables or connectors to prevent short circuits. • Connect the speaker wires to appropriate speaker connectors separately. Sharing the negative wire of the speaker or grounding speaker wires to the metal body of the car can cause this unit to fail. • After installation, check that the brake lamps, winkers, and wipers work properly. ■ Speaker level input terminals (!) • The genuine-accessory car stereo shall have a maximum power output of no more than 40 W. • Do not connect the speaker output leads from a power amplifier (Optional) to the speaker level input terminals of this unit, for this may cause malfunction or damage. • Do not connect cables and leads to both RCA cable input jacks and the speaker level input terminals simultaneously, for this may cause malfunction or damage. • Connect the power control lead to a power supply which can be turned ON/OFF by the ignition key switch (ACC line). With this connection, shock noise may be generated when the power of the genuine-accessory car stereo is switched ON/OFF. ■ Accessories Part name External View Terminal cover (Power terminal) 1 Self-tapping screws (ø4 ´ 16 mm) 4 Speaker level input cable 1 Installation Since the power amplifier has no parts which require operation, it can be installed at a position away from the driver’s seat without any hindrances. As generally accepted positions for its installation, places such as inside the trunk, etc. can be considered. 2CAUTION • Do not install the unit under the carpet. Otherwise heat build-up occurs and the unit may be damaged. • Install this unit in a location which allows heat to easily dissipate. Once installed, do not place any object on top of the unit. • The surface temperature of the amplifier will become hot during use. Install the amplifier in a place where people, resins, and other substances that are sensitive to heat will not come into contact with it. • When making a hole under a seat, inside the trunk, or somewhere else in the vehicle, check that there is nothing hazardous on the opposite side such as a gasoline tank, brake pipe, or wiring harness, and be careful not to cause scratches or other damage. • Do not install near the dashboard, rear tray, or air bag safety parts. • The installation to the vehicle should securely fasten the unit to a place in which it will not obstruct driving. If the unit comes off due to a shock and hits a person or safety part, it may cause injury or an accident. • After installing the unit, check to make sure that electrical equipment such as the brake lamps, turn signal lamps and windshield wipers operate normally. Self-tapping screw (ø4 ´ 16 mm) ■ Power terminal (234) Connect to their respective terminals the power supply wire, and ground wire, all of which pass through the associated terminal cover. Once the connections are complete, place the cover on the terminal section. Number of Items Installation board, etc. (thickness : 15 mm or more) Controls 6 POWER IN FUSE(40A) GND BATT. BRIDGED LEFT SPEAKER P.CON OUTPUT FILTER A.CH BASS BOOST(B.CH) RIGHT 1 0.5 2 40 3 4 B 0.3 (MIN)5 0.2(MAX) A.CH POWER AMPLIFIER A.CH OFF HPF LPF 1 A OPERATION B.CH OFF HPF LPF OFF ON 100 80 0.5 2 3 4 STEREO 80 150 100 100 80 STEREO MONO(Lch) A B 80 5 6 GND 150 3 4 SPEAKER LEVEL INPUT A R B L BASS BOOST(B.CH) OFF ON A.CH FILTER OFF HPF LPF B.CH OFF HPF LPF R # @ This is a 4 channel amplifier including 2 stereo amplifiers in a body. One amplifier is referred to as amplifier A and the other is amplifier B. This unit is compatible with a large variety of systems by combining the switches and functions described in the following. $ OPERATION A.CH STEREO $ A L R B L R INPUT SELECTOR % B.CH MONO(Lch) STEREO MONO(Lch) A B OFF HPF LPF ■ 2-channel OPERATION A.CH STEREO $ A L R B A B CENTER UNIT OPERATION A.CH $ A L R B 80 # OFF HPF LPF 150 100 100 80 80 L R B R D GN BASS BOOST(B.CH) OFF ON L R Subwoofer 80 B.CH 100 80 3 4 A B 80 150 150 100 100 80 150 OFF ON A.CH 50 LPF 200 50 LPF 200 50 HPF 200 50 HPF 200 B.CH A.CH FILTER FREQUENCY(Hz) A Lead terminal* 5 ED IDG BR A B R 80 INPUT SELECTOR B.CH MONO(Lch) 150 100 100 80 STEREO MONO(Lch) A B 80 A LINE IN A B LINE OUT A + B L 150 100 150 0.3 GND 150 SPEAKER LEVEL INPUT 50 LPF 200 50 LPF 200 50 HPF 200 50 HPF 200 B.CH A.CH FILTER FREQUENCY(Hz) (MIN)5 0.2(MAX) (MIN)5 0.2(MAX) A.CH B.CH INPUT SENSITIVITY(V) B L A R B L R Battery ■ Speaker bridge connection A L A Bridge R Lead terminal* 4 5 FT LE ED IDG BR 4 HT RIG FT LE POWER IN FUSE(40A) BATT. GND SPEAKER P.CON OUTPUT BRIDGED LEFT POWER IN RIGHT FUSE(40A) FILTER 80 L R # 150 100 OFF HPF LPF A.CH FILTER OFF HPF LPF # B.CH OFF HPF LPF 100 80 80 OFF ON @ SPEAKER P.CON OUTPUT BRIDGED LEFT RIGHT A B POWER AMPLIFIER BRIDGED 150 100 BRIDGED A A B 150 L B R L L B R R B Bridge Crossover Frequency L High pass ■ Power wire connection -3 dB L Description of markings in the figure. L Subwoofer (L + R) BASS BOOST(B.CH) OFF ON GND POWER AMPLIFIER BASS BOOST(B.CH) 0 dB L R BATT. B B.CH @ Principle of Tri-mode Method of frequency band division using a coil and capacitor ... in case of 6dB/oct. slope Coil (L): Passes low frequencies and blocks high frequencies. (Low pass) Capacitor (C): Passes high frequencies and blocks low frequencies. (High pass) Example: When it is required to set a crossover frequency of 120 Hz using speakers with an impedance of 4 ohms. fc=Cut of Frequency (Hz) R=Speaker Impedance (½) C POWER IN FUSE(40A) BATT. GND SPEAKER P.CON OUTPUT BRIDGED LEFT A RIGHT A Frequency B POWER AMPLIFIER 159000 159000 = 331.25 µF C= (µF) = 120Hz x 4½ fc x R 159 x R 159 x 4½ L= (mH) = = 5.3 mH fc 120Hz 2 34 R A B Lead terminal* Terminal cover 2CAUTION • If you wish to bridge-connect a speaker, the speaker impedance must be no less than 4 ohms. Connecting a speaker with an impedance lower than 4 ohms may damage the unit. • Be sure to connect capacitors to speakers to which high frequencies will be passed. Failure to do so will result in a drop of the combined impedance with the subwoofer. • Ensure that the withstand voltage and current ratings of the capacitors (C) and coils (L) are sufficient. L A 40 MONO(Lch) STEREO MONO(Lch) % A A R A.CH STEREO 100 80 0.5 2 3 4 0.3 OPERATION B.CH OFF HPF LPF 1 0.5 A C B.CH FILTER A.CH OFF HPF LPF 1 2 3 4 SPEAKER LEVEL INPUT HT RIG Right speaker OFF HPF LPF C INPUT SELECTOR OFF ON GND ■ Speaker stereo connection Left speaker C B BASS BOOST(B.CH) L 150 100 150 B L R B LINE OUT A + B @ 150 L R B C A B 150 100 L A R % A L R LINE IN A Car fuse box ■ Tri-mode CENTER UNIT 80 A R B BASS BOOST(B.CH) 7 STEREO 80 0.3 STEREO MONO(Lch) A B L ACC 50 LPF 200 50 LPF 200 50 HPF 200 50 HPF 200 B.CH A.CH FILTER FREQUENCY(Hz) A.CH 100 80 0.5 INPUT SELECTOR B.CH MONO(Lch) STEREO R A 7 150 $ 2 3 4 (MIN)5 0.2(MAX) (MIN)5 0.2(MAX) A.CH B.CH INPUT SENSITIVITY(V) 50 LPF 200 50 LPF 200 50 HPF 200 50 HPF 200 B.CH A.CH FILTER FREQUENCY(Hz) 100 80 OPERATION 0.3 A.CH OFF HPF LPF 1 0.5 OPERATION B.CH R L Power control wire* OFF HPF LPF 150 100 OFF HPF LPF 1 B # FILTER A.CH B L 40 MONO(Lch) STEREO MONO(Lch) L R INPUT SELECTOR B.CH L 150 FILTER White White/Black Gray Gray/Black Green Green/Black Purple Purple/Black L A R A 8 Genuine-accessory car stereo (No line output center unit etc.) Cable Color of the connector 40 STEREO $ A ■ Speaker level input connection CENTER UNIT (Cassette receiver, CD receiver, etc.) @ ■ 2-channel CENTER UNIT A.CH ■ RCA cable connection 150 100 Left speaker Right speaker 100 80 ■ 2-channel OPERATION OFF ON L R A.CH A L R Amplifies both of the signals input to amplifiers A and B. BASS BOOST(B.CH) A OFF HPF LPF % A B • A B position: For safe installation, read "Installation procedure" before starting work. 2 INPUT SELECTOR B.CH MONO(Lch) STEREO MONO(Lch) This switch selects the input method of the signals to be amplified by amplifiers A and B. RCA cable* B.CH ■ 3-channel A L R % INPUT SELECTOR switch 7 % B.CH Amplifies the signal input from the left side only. Set to this position and make bridged connections to use as a high-power monaural amplifier. (The input right signal is not output.) 50 LPF 200 50 LPF 200 50 HPF 200 50 HPF 200 B.CH A.CH FILTER FREQUENCY(Hz) ■ 2ch + woofer STEREO NOTE INPUT SELECTOR MONO(Lch) STEREO MONO(Lch) The amplifier can be used as a stereo amplifier. • MONO (Lch) position: • A position: 150 L R • STEREO position: When the switch is in “ON” position, the bass is boosted by 6 dB. The bass boost applies only to the B amplifier. Front left speaker Front right speaker Rear left speaker Rear right speaker FILTER A.CH A 100 80 CENTER UNIT The amplification methods of the signals input to amplifiers A and B can be selected independently according to the setting of this switch. ! Speaker level input terminals @ BASS BOOST switch ■ 4-channel B This unit is equipped with a protection function for protecting this unit and your speakers from various accidents or problems that can occur. When the protection function is triggered, the Power indicator goes off and the amplifier stops operating. • When a speaker wire may be short-circuited. • When a speaker output contacts ground. • When the unit malfunctions and a DC signal is sent to the speaker output. • When the internal temperature is high and unit won’t operate. • When a ground wire of the center unit (cassette receiver, CD receiver, etc.) or this unit is not connected to a metal part serving as an electrical ground passing electricity to the battery's negative - terminal. Connection ■ 4-channel L R ■ The protection function is activated in the following situations: $ OPERATION switch System examples A The filter outputs the band of lower frequencies than the frequency set with the FILTER FREQUENCY control. The speaker output is automatically turned monaural (L+R). These jacks output respectively the signals input to amplifiers A and B. They always output the stereo signals regardless of the position of the OPERATION switch. Set this control according to the pre-output level of the center unit connected with this unit, or to the maximum power output of the genuine-accessory car stereo. The sensitivities of amplifiers A and B can be L R The entire bandwidth is output without filtering. • LPF (Low-Pass Filter) position: 9 Amplifier A/B LINE IN terminals 0 LINE OUT terminal 6 INPUT SENSITIVITY control When the power is turned on, the Power indicator lights. If the Power indicator does not light when the power is turned on, the protection function may be activated. Check whether there is any indication of trouble. • OFF position: Do not use this terminal for power source grounding. This unit will be damaged if the power source grounding wire is connected to this terminal. When you wish to use the unit as a high-output monaural amplifier, bridged connections are used. (Make connections to the LEFT channel (+) and the RIGHT channel (–) SPEAKER OUTPUT terminals.) R The filter outputs the band of higher frequencies than the frequency set with the FILTER FREQUENCY control. 2CAUTION KAC-749S Power indicator • HPF (High-Pass Filter) position: When using an RCA cable with a ground lead attached, connect the ground lead to this terminal. • Bridged Connections: Power indicator Amplifies only signal input amplifier A with both amplifiers A and B. This switch allows to apply high-pass or low-pass filtering to the speaker outputs. 8 RCA cable ground lead terminal When you wish to use the unit as a stereo amplifier, stereo connections are used. KAC-749S # FILTER switch When the FILTER switch is set to the HPF (HighPass Filter) or LPF (Low-Pass Filter) position, the threshold frequency can be adjusted with this control. 2 Battery terminal 3 Ground terminal 4 Power control terminal 5 Amplifier A/B SPEAKER OUTPUT terminals • Stereo Connections: MAXIMUM POWER INPUT SENSITIVITY(V) KAC-849 7 FILTER FREQUENCY control If you can’t find the specified capacity fuse at your store etc., consult your Kenwood dealer. ! % NOTE NOTE 0 KAC-849 A For the pre-output level or the maximum power output, refer to the “Specifications” in the instruction manual of the center unit. 40 A ´ 1 : KAC-849 30 A ´ 1 : KAC-749S F 9 4/3/2 CHANNEL AMPLIFIER 4/3/2 CHANNEL AMPLIFIER 0.2(MAX) INPUT SELECTOR STEREO MONO(Lch) A B adjusted independently regardless of the position of the input selector switch. Use the diagram on the right as a guide. 1 Fuse CENTER UNIT B.CH MONO(Lch) 8 15 10 (W) 0.3 MAXIMUM POWER OPERATION A.CH STEREO 7 0.5 25 2 (MIN)5 1 2 3 4 40 1 LINE OUT A + B B L 50 LPF 200 50 LPF 200 50 HPF 200 50 HPF 200 B.CH A.CH FILTER FREQUENCY(Hz) INPUT SENSITIVITY(V) A A 150 100 150 0.3 (MIN)5 0.2(MAX) B.CH LINE IN INPUT SELECTOR B.CH MONO(Lch) Power control wire* Battery wire* Ground wire* Protective Fuse* Battery B L B R F R * Left Front left Front right Right Rear left Rear right Front Rear Commercially available parts