User manual JBL GTS180

[. . . ] In addition to conventional preamp-level inputs, this model features JBL's Universal Interface design, which facilitates simple connection to factory radios with the low distortion that is usually only associated with preamp level connection. With Universal Interface, a factory radio can be used either as the main music source or combined with a CD changer which includes volume control capability, simultaneously connected directly to the amplifier. By providing this two-unit direct connection, Universal Interface circuitry eliminates the need for an FM modulator to connect a CD player to factory radios, improving the fidelity of digital playback. Also, when using a high-powered (BTL) radio through the speaker-level inputs, Common Sense turn-on circuitry senses the common-mode voltage present on the radio's speaker wires and turns the amplifier on without an additional "remote" wire. [. . . ] Main speakers are connected normally to the left and right stereo outputs, and a centerchannel or subwoofer speaker is connected in bridged mode. Refer to the diagram on page 19 in the "Speaker Connections" section for details. Speaker Level Input Connections When speaker level signal is used to drive the GTS180, the signal goes into the amp through a special four wire harness/connector (see the "Controls and Connectors" section) If extension wires are needed between the head unit output and the amplifier unit, use conventional speaker wire. Keep the wiring inside the passenger and trunk compartments and make the wires as short as possible. All connections should be securely crimped or soldered and insulated with heatshrink tubing. Use the color code of the input harness wires and the identification on the radio/tape deck output wires to be sure that left and right channels are correctly connected and the positive/negative polarity of each channel is connected correctly. For example, the left positive output of the head unit must be connected to the left positive input of the GTS180. The color code for the speaker level input harness is as follows: Standard Operation ­ When using the GTS180 as a conventional stereo amplifier simply connect the preamplevel source outputs directly to the two gold RCA connectors or connect the head unit speaker outputs to the speaker-level inputs with the input mode switch set to "stereo. " When using two sources, both the speaker and preamp-level inputs may be used simultaneously. Be sure to maintain left and right channel consistency. Bridged Mode Operation ­ To select bridge mode operation, set the input mode switch in either the "R" only or "L+R" position. In the "R" position, signal from the right channel input is fed to both amplifier channels. In the "L+R" position, the signal from both channels is summed internally. All two conductor speaker wire has one conductor marked in some way so it can be easily traced. The speaker output wire harness color codes are listed below: Speaker Output Color Codes Left (+): Left (-): Right (+): Right (-): White White with Black Stripe Gray Gray with Black Stripe Stereo Connection ­ Connect each speaker directly to the speaker output harness according to the color-code listed above. The input-mode switch should be set to "STEREO" Bridged-mode Connection ­ Connect the loudspeaker positive (+) terminal to the RIGHT channel positive wire (Gray). Connect the loudspeaker negative (­) terminal to the LEFT channel negative wire (White with Black stripe). The input-mode switch should be set to "R" or "L+R". Simultaneous Stereo + Mono Connection ­ The GTS180 may be used to drive a stereo pair of speakers with a mono (bridged) speaker at the same time. This is sometimes used for center-channel applications or for inexpensive subwoofer addition, essentially creating a 3-channel system. However, unlike a true bi-amplified subwoofer connection, this system configuration does not provide for control of subwoofer-satellite balance, it requires the use of a passive subwoofer crossover instead of the superior active circuitry already built-in to the GTS180, and it does not separate the power amps driving the satellites from the amps driving the subwoofer. Therefore this connection is best used for addition of a center-channel, or as an interim step as you build up to a true bi-amplified subwoofer-satellite system. Connect the main pair of stereo speakers as in the stereo mode, connect the mono speaker as described above for bridge-mode connection (see diagram on page 19). For use in center channel applications, a high-power "L-Pad" or power fader can be used to attenuate the center channel for proper level matching. [. . . ] Next Step: Add more subwoofer power. Front Outputs GTS180 GTS180 Preamp output to preamp input GTS180 GTS180 Rear Outputs GTS180 GTS180 Front Satellite Speakers Rear Satellite Speakers L­ L+ ­ + R­ R+ ­ + ­ + L­ L+ ­ + R­ R+ ­ + 1 or 2 Subwoofers System 5 Add a Second Subwoofer Amplifier Front Outputs Preamp output to preamp input Rear Outputs For the ultimate in GTS180 GTS180 GTS180 bass output, add a second subwoofer amplifier for a total system power of 340 Watts RMS!Note the crossFront Satellite linking of preamp Subwoofers Speakers inputs for the two L­ L+ R­ R+ ­ + ­ + subwoofer ­ +­ + amplifiers to provide nonfading bass. Next Step: Add additional amplifiers in bridge-mode to the front and rear main speakers. Then add electronic crossovers and biamp front and rear speakers. GTS180 GTS180 GTS180 GTS180 GTS180 Rear Satellite Speakers L­ L+ ­ + R­ R+ ­ + 26 In Case of Difficulty Power-on light does not come on. [. . . ]