Quantum Audio QS1500D, QS2150, QS4150 Adjusting the Crossover and Bass, Fine Tune the System

5v .2v

ADJUSTING THE CROSSOVER AND BASS

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The SOLAR series amplifiers are equipped with a built-in variable crossover network allowing you to select the crossover type (i.e. Low-Pass or High-Pass) and the desired crossover point. For example if you wish to drive a pair of subwoofers, you can select the “Low Pass” setting on the amplifier to filter out high frequencies. This will send only low frequencies to your subwoofers (see example settings below). The crossover point should be determined by the speakers operating range. Please refer to speaker manufactures recommended crossover point.

Bass Boost @ 45Hz

0 ~ 12dB

In this example we have selected

LPF (Low Pass Filter) for our XOVER.

Adjust the LPF (Low Pass Frequency)

to desired crossover point for your speakers

line	+ - GND - +			lpf
L	HI
	INPUT			full hpf
	5v .2v	0dB 12dB	60Hz 1.2KHz	30Hz 250Hz
R	LEVEL	BASS	HPF	LPF X-over
		EQ
output	input

MONO

STEREO

Mode

FINE TUNE THE SYSTEM

Fine tune the amplifier's input sensitivity.

The input gain sensitivity control for the “Solar Series” amplifier is located on the side panel. This gain control has been included to allow adjustment to properly match the output of the radio. This is one of the most misunderstood adjustments. By rotating the control in the clockwise direction, the amplifier‘s input will become more sensitive and the music will play louder. This

is not a volume control and you will not get more power out of the amplifier in the maximum position! It may seem to deliver more output, but actually the system is only playing louder faster as you turn the volume control on the radio. Ideally, to properly level match the system the goal is to achieve maximum output from the amplifier without distortion at about 3/4 of the volume control.

To determine if the amplifier’s gain is set properly, turn the system on and slowly increase the volume control. You should be able to use about 3/4 volume before the system gets loud but not distorting. It is very important when making these adjustments that you do not over drive the speakers (at point of distortion) this will cause permanent damage to the speakers. If you are unable to achieve 3/4 volume before distortion you will need to adjust gain control (in this case you would reduce the gain). The gain controls should be adjusted very slowly. It may help to have another person to assist you by adjusting the gain controls while you listen for distortion.

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