CROSSOVER, Subsonic and Gain

C r o s s o v e r

PC-1400

Your new Monoblock amplifier has a variable 20-5kHz 12dB/Octave HP/ LP crossover. When you select the LP feature on this amplifier you have made the output RCA's HP, and vice versa when you select HP for the speaker output.

PC-1800

The PC-1400 has a variable fourth-order Linkwitz-Riley type, 24dB per octave LP crossover built in to provide system flexibility without the added expense and installation of an outboard crossover. The speaker outputs of the amplifier are all pass or LP according to the LP ON/OFF switch on the amplifier's front endplate. You would choose LP (switch in) to use this amp for subwoofers, or choose all pass (switch out) to use this amp for full range speakers. Selection of low pass lets you vary the crossover point from 50Hz to 300Hz using the detented LP FREQ. control, 50Hz being fully counterclockwise. (see frequency detent charts on pg.16 )

Subsonic Filter

You will also find the SUBSONIC ON/OFF switch on the front endplate of your PC-1800. This is a 24dB per octave HP crossover used to clean up the sound of your subwoofers, and is especially useful with ported or bandpass sub enclosures with steeper rolloffs at low frequencies. With the Subsonic filter switch in, you can vary the HP frequency from 5Hz

to 50Hz using the detented SUBSONIC FREQ. control, 5Hz being fully counterclockwise. Refer to the Frequency Chart on page 13 to set your frequency or adjust the filter to the lowest frequency and turn the control clockwise as the music plays. You will notice increased detail to a point and then you will notice a decrease in bass. Turn back to the detent frequency just before you started losing bass.

A d j u s t i n g T h e A m p l i f i e r I n p u t G a i n

1. Adjust all amplifier input gain controls to just above minimum sensitivity (fully counterclockwise).

2.Using the cleanest source (CD), with music playing turn up the head unit until you can hear distortion. Now turn it down a bit until you cannot hear the distortion.

3.Increase the Amplifier gain (clockwise) until the onset of audible distortion. Then decrease the gain to the point just before the distortion starts. This setting minimizes background noise and prevents overload.

4.Repeat step 3 for any remaining amplifiers in the system. 15

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