JBL GTS100 owner manual Operation, Gain Adjustments, Other Characteristics

Operation

Before operating the GTS100, recheck all wiring connections to make sure they are correct and secure. Be sure that a 20 amp fuse (not included) is installed in the +12V line next to the battery. Reconnect the negative ground (–) terminal of the battery. Make sure

that the input mode selector, crossover switch and preamp mode switch are properly set.

Gain Adjustments

The setting of the gain control on the GTS100 is important to ensure proper performance, low noise levels, and maximum reliability in the system. As a general rule, controls on components at the front-end of the system (Source, equalizers, electronic crossovers, etc.) should be set as high as possible, with the amplifier gain control set as low

as possible while still providing ade- quate volume levels. Using a high sig- nal level from the source and a low gain setting on the amplifier will help keep background noise levels in the system low.

To adjust a system using a single amplifier, start with the amplifier input sensitivity controls fully counterclock- wise. Some radio/tape decks have addi- tional output level controls or switches. Set those to their maximum position. Set the level controls on any associated equipment such as equalizers and electronic crossovers to the maximum position or as recommended by the manufacturer. Set all Bass/Treble or equalizer controls to their centered or bypassed positions. While listening

carefully to the system output, adjust the volume control of the radio/tape deck to the point where you first begin to hear audible distortion. Reduce the level just to the point where the distor- tion goes away. This is the maximum undistorted output level of your head unit and signal processors, and should not be exceeded during use. If audible distortion does not occur, continue to increase the level until the head unit is turned all the way up. If this setting does not provide adequate volume lev- els, gradually increase (turn clockwise) the gain control of the GTS100 until the system plays as loud as necessary or when the first signs of distortion are heard.

When multiple amplifiers are used in the system, it is best to adjust the gain of the amplifier driving the main (usually front) speakers first. Then turn down the head unit’s volume control to a comfort- able level, and adjust the remaining amplifiers for the desired system bal- ance. You will find this easiest to do by adjusting the amplifiers in the following order: 1) front-channels, 2) rear-chan- nels, 3) subwoofers. Complex systems incorporating tri-or quad-amplification can be time consuming to adjust. Your local authorized JBL installation special- ist is the best person to help with such adjustment.

Other Characteristics

Turn-On Delay – When installed as described in this manual, the GTS100 will turn on and off with the head unit or the vehicle’s ignition switch. When the amplifier is turned on, there is a time delay of several seconds (longer in cold

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