JBL GTH400-20107 manual

GTH400-20107 06/03/98 15:49 Side 26[...]

GTH400 GTH400 6/5/4/3 CHANNEL AUTOMOTIVE POWER AMPLIFIER OWNER’S MANUAL GTH400-20107 06/03/98 15:49 Side 1[...]

T able of Contents 1. Introduction ...................................................................................... 3 1.1 Features .................................................................................... 4 1.2 About Installation ...................................................................... 4 2. Installation and use ......[...]

3 1. Introduction Thanks for purchasing your new GT series automotive multichannel ampli- fier. Your GT series amplifier will easily connect to virtually any car audio system, whether it is factory installed or one purchased separately. The GTH400 includes an abundance of unique features which are described in this manual. The most obvious feature [...]

4 1.1 Features Theory of Operation – Virtual Center Image Enhancer JBL’s breakthrough “Virtual Center” circuitry is the result of the understanding of how the human ear responds to timing, frequency, and amplitude cues to determine the apparent direction of a sound source. Virtual Center circuitry manipulates the analog signal in real time [...]

5 2. Installation and use Refer to the “Crossover Frequency Adjustments” and “Speaker-Level Input Impedance Adjustments” sections of this manual to see if you will need to make alterations to their factory settings. 1. Disconnect the negative cable from the battery. Note: If the vehicle’s radio features a code type security system, make c[...]

3. System Design Using the GTH400 3.1 Speaker Requirements When used in the non-bridged mode a group-channel of the GTH400 can easily drive two 2-ohm speaker loads. When only one speaker is connected to the left and right outputs of a group, virtually any conventional speaker may be used. When two speakers are connected in parallel to a single outp[...]

7 3.2 Typical Applications The diagrams on pages 8 & 9 show the most common basic system configurations of the GTH400. One or more of these building blocks may be combined to form elaborate system designs. The GTH400 uses the terminology “Group 1,” “Group 2” and “Group 3” to indicate the three main signal paths within the amplifier.[...]

8 L L R L R + L – Application 4 3-Channel Bi-Amplified 4-Channel Input (Fading Subwoofer) L L R R GR 1 GR 3 GR 2 Group 1 Group 2 Group 3 Input Mode L L L+R Group 2 Input – GR 2 – Group 3 Input – – GR 3 Speaker Crossover High Pass High Pass Low Pass Preamp Output Crossover – – – 2-Channel Input (Mono Subwoofer) Group 1 Group 2 Group [...]

9 4. Installation and Use 4.1 Controls and Connectors 1. Preamp-Level Input Connector – Use these connectors for line (pre- amp) level inputs to the amplifier. 2. Preamp-Level Output Connector – Use these outputs to send signal to additional amplifiers. 3. Speaker-Level Input Connector – Use this connector for speaker level input signals. A w[...]

10 to use in conjunction with a high- pass filtered input signal to create a bandpass crossover (for a midrange or midbass driver). Set the switch to H (high) to activate the high-pass filter for use with satellite speakers or tweeters on an amplifier group. 13. Mode Switches – These switches are used to set the input mode for both preamp and spe[...]

11 + - + - + - Buffer Buffer Buffer Buffer Buffer Buffer 1 2 3 1 2 3 1 2 3 1 2 1 2 1 2 3 1 2 3 1 2 3 1 2 3 CH. 1 L IN CH. 1 R IN CH. 2 L IN CH. 2 R IN CH. 1 L OUT CH. 1 R OUT CH. 2 L OUT CH. 2 R OUT IMAGE ENH. 1 2 3 GROUP 3 INPUT + + 1 – GR 3 2 – GR 2 3 – GR 1+2 1 Speaker Crossover 1 – Flat 2 – Low Pass 3 – High Pass Preamp Crossover 1 [...]

12 4.2 Internal Adjustments Speaker-Level Input Impedance Adjustments The speaker level inputs of the GTH400 come factory set with 100k ohm input impedance. This will provide the lowest distortion operation from the speaker outputs of most modern head units by reducing the power the amplifier in the head unit must deliver to practically nothing. On[...]

13 Custom Chip Construction Regardless of whether you build or buy it, the necessary resistor network has the following configuration: • Each resistor in the package has the same value. • If you know the crossover frequency you want, you can calculate the resistor value necessary by solving the following equation: Resistor 2,500,000 Value = Fre[...]

14 Under-Dash Remote Installation 1. Set the GTH400 remote in the installation location and mark two mounting screw hole locations. 2. Set the GTH400 remote aside and drill two pilot holes using a 1⁄16"- (1mm) bit. Be careful not to drill into any of the car’s components. 3. Secure the spacer and faceplate (with the control labeling) to th[...]

15 FACE PLATE DASH PANEL SPACER PLATE (INCLUDED) FACE PLATE Cassette/CD Tuner CD Player or Changer CD Input Cassette/CD Preamp Output Antenna Input Power Antenna Power Antenna Relay Blue w/White Stripe - Remote On/Off Main +12V Power Ground Chassis Ground Vehicle Battery – + Ignition Switch Antenna Motor Power Supply Blue (Blue/White) Remote On/O[...]

16 is heat- and oil-resistant whenever running wires through the engine compartment. All wire-to-wire connections should be soldered and insulated with heat shrink tubing, or connected through a high-quality insulated crimp-on connector or secure set-screw-type terminal blocks. Never leave bare wire exposed. Terminate wires with crimp- or solder-on[...]

17 • The GTH400 will draw as much as 60 amps from the vehicle’s electrical system, enough to overload conventional vehicle wiring. Therefore the +12 volt power supply must be taken directly from the positive side of the battery. Do not connect to the vehicle’s fuse block or to a wire feeding other accessories. • To prevent electrical system[...]

18 background noise levels in the system low. • To adjust a system using a single GTH400, start with all three of the amplifier gain controls fully counterclockwise and the Imaging Enhancer Remote set to “Bypass” mode. Some head units have additional output level controls or switches. Set those to their maximum position. • Set the level con[...]

19 position for driver-optimized sound stage. 5. Proceed to push and pull the Rear- Ambience knob to hear the effects of “Driver” and “All” modes. You should hear imaging coming from the middle of the dashboard when the knob is pushed in (“Driver” mode). You should hear stereo with ambience recovery when the knob is pulled out (“All?[...]

20 and off, or does not work at all, a problem in installation or an abnormal electrical condition is indicated. Check speaker wiring for short circuits or impedance loads significantly below 2 ohms (4 ohms in bridged mode). Check the power supply voltage at the input of the amplifier to be sure that it is normal; between 11 and 16 volts. Check tha[...]

21 7. In Case of Difficulty Power-on light does not come on • Head unit not on; turn the head unit on. • Ground wire is disconnected or defective; check for continuity with an ohmmeter between the amplifier’s ground terminal and a known chassis ground point. • Battery wire is disconnected or defective; check for approximately +12 volts betw[...]

22 Power light is on, but no sound is heard • Defective head unit or signal processor; from some or all of the speakers check each component for proper wiring and operation. • Defective GTH400; If there is audio signal present at the inputs of the amplifier and there is no output, the GTH400 may be defective. Alternator whine through the audio [...]

23 8. Specifications GTH400 35 Watts x 4 + 70 Watts x 2 (4 ohms, 0.05% THD) 50 Watts x 4 + 100 Watts x 2 (2 ohms, 0.08% THD) 100 Watts x 2 (Bridged 4 ohms, 0.08% THD) + 70 Watts x 2 (4 ohms, 0.05% THD) 100 Watts x 2 (Bridged 4 ohms, 0.08% THD) + 200 Watts x 1 (Bridged 4 ohms, at 0.08% THD) Signal to Noise Ratio 100dBA Frequency Response 10Hz – 50[...]

24 9/64" (3.5mm) in 4 places 9/64" (3.5mm) in 2 places 25/64" (10mm) drill in 2 places UP UP Remote Control Drilling Template Power Requirement 11 to 16V DC Negative Ground Fuse Size 30 Amp ATC Type Fuse (2 per Amplifier) Size (L x W x H) 15-1/4" x 11-1/4" x 2" (387mm x 286mm x 51mm) Weight 13 lbs 4 oz (6 kg) Speaker L[...]

25 Staple or clip your original bill of sale here. ▼ GTH400-20107 06/03/98 15:50 Side 25[...]