quick question about amps

[Tyler04]

If an amp says it has "variable low-pass filter (50-300 Hz, 12 dB/octave)", what exactly does that mean?

[czechm8]

It means its capable of converting a full range signal into only a low frequency range signal (for subwoofer duty) at a point anywhere from 50 Hz to 300 Hz on a 12 db slope (2nd order). example: if your reference point is a 0 db signal, the crossovers' 12 db slope will taper off, or reduce the output of that particular frequency by 12 db for each octave you go down.

Here's some good information. Look at chapter 27 specifically.

Basic Car Audio Electronics

[ktaulbee]

^^^ What he said. Basically used for powering subwoofers. The variable low pass filter means that you can select the frequency cut off for the subs you are running from 50-300hz. So the amp will only(basically only) send low frequencies to the driver.

[Tyler04]

oh ok, that makes sense. thanks a lot