JBL GTH400-20107 manual Important Characteristics

GTH400-20107 06/03/98 15:50 Side 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” mode). If you find that the center imaging in the “Driver” position is slightly offset to the left or right side of the dashboard, switch the car-size switch located inside of the GTH400 under the bottom cover as shown below. This switch optimizes the Imaging Enhancer for standard or large cars.

IMAGING ENHANCER
REMOTE	PLUG	FRONT
		PLATE

Imaging Enhancer
Car Size Switch	IMAGE
	ENHANCER
	MODULE

StandardLarge

6.Slowly turn the “Front-Ambience” knob in the clockwise direction to increase ambience. You should begin to hear slight reverberation in the music and a sense of a widening front sound stage in both the “Driver” and “All” modes.

7.Slowly turn the “Rear-Ambience” knob in the clockwise direction to increase rear ambience (only in

systems with rear speakers). You should begin to hear an increase in reverberation and get a feeling of being in a very large auditorium. Note: The GTH400 converts the rear channels into true rear-fill surround channels which cancel all center information (vocals, lead instruments, etc.) and lets only true ambience information come out. This same process is used in more expensive “Surround Sound” systems used in theaters.

8.Adjust the front and rear ambience as desired. For optimum center imaging, it is recommended that ambience be used sparingly on the front channels.

9.To bypass the effects of the Imaging Enhancer in the GTH400, simply pull on the “Front- Ambience” knob until it clicks to the “Bypass” position. The “Enhancer On” LED on the remote control panel will turn off and your sound system should revert back to normal stereo sound without ambience enhancement. The Imaging Enhancer is also bypassed when the remote control is unplugged from the amplifier.

6. Important Characteristics

Overload Protection – The GTH400 incorporates elaborate protection cir- cuitry to prevent damage to the amplifier circuitry and ensure reliable operation. This circuitry will turn the amplifier off in the event of overheating, a short circuit on the speaker output wiring, or improper power supply connections. If the amplifier cycles on

19