Specifications

page 11

If your system design calls out for crossover frequencies that

your dealers does not stock, you can create custom modules by

using the following formula:

__7200___ = Resistor Value In Kilohms

Frequency (Hz)

Example:

For a 2500Hz module - 7200/2500=2.88K ohms

The 24 dB crossover module requires eight

resistors of this value.

Note: Use

⁄

4 watt carbon or metal

film resistors of a 5% tolerance or

better.

USING THE PFM

(PROGRAMMABLE FREQUENCY MATCH) FILTER

Many car audio systems truly push the limits of their subwoofer

. . . without really knowing it. Tuned enclosures affect the roll-off

of many speakers, yet lots of source material forces the speakers to

play lower than expected. The net result is wasted amplifier power

and damaged speakers. The AudioControl PFM (Programmable

Frequency Match) filter is a programmable subsonic filter. It allows

you to only let the speaker(s) play as low as they should be playing.

Because every system is different, we allow you to change the PFM

roll-off frequency to whatever you choose.

On most systems, the factory installed module (33Hz) is fine.

However, if you know the tuning frequency of your speaker enclo-

sure (porting frequency or 3dB down point), you might try setting

your PFM module to that frequency. If you want to protect your

speaker system even more, you might even try a higher frequency.