JBL GTH400-20107 Features Theory of Operation Virtual Center Image Enhancer, About Installation

GTH400-20107 06/03/98 15:49 Side 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 to provide each of the driver’s ears with the signal they would receive if the driver was seated in the center of the vehicle. This provides a stable, centered image to the driver much like that obtained with a dedicated center-channel loudspeaker.

To restore the spaciousness that is generally lost in the small confines of a car interior, the rear channels utilize differential-mode ambience recovery to restore the ambience information pres- ent in all conventional stereo recordings. Unlike DSP, the JBL circuitry does not add synthetic reverb, but recovers real information that is masked in conventional systems. As a result, the overall effect from the Virtual Center circuitry of the GTH400 is incredibly realistic, yet simple to adjust and use. Best of all, the “Virtual Center” and ambiance recovery circuits do not require specially encoded recordings and work with virtually all conventional stereo tapes, discs, and broadcasts.

1.2 About Installation

Although the GTH400 is designed to make installation as easy as possible, it is an extremely sophisticated product that requires proper installation and setup to realize its full performance potential. If you feel you do not have the necessary knowledge and skills, we

strongly recommend that the installation be done by your authorized JBL dealer.

If you choose to install the GTH400 yourself, read all of the information in this manual before you start the installation. Pay particular attention to the safety precautions and notes.

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