Low Pass Filter Settings?

[R 2 THE J]

Recently purchased an 12" MTX 4500 Sub in a PORTED BOX for my R33. I also have a Jensen Mono amplifier.

I was enquiring about what freuency should I set my Low Pass Frequency at?

I listen to a lot of Rap & R&B and was wondering if anybody could help?

The Low Pass Filter Settings on my amp range from 40hz to 300hz.

Also what should I set my Gain and Bass at?

Settings for Bass are 0db up to 19db and for gain is 8 to 100 not sure about the units type specified!

Thanks...all help will be muchly appreciated!

Edited February 18, 2008 by R33s_can_drift

[bloodsword27]

set it to 80Hz then go up/down from there til you are happy with the sound

[mikel]

80 Hz is as good a place to start as any.

It depends a little on whether there's a corresponding high pass filter for the main speakers, ie you have a crossover pair (high pass filter feeding the main speakers and low pass feeding the sub).

If you don't then the best place to set the sub crossover is where the main speakers naturally start to rolloff. Then you'll minimise a hump in the frequency response with your sub playing the same frequencies as the main speakers. If you set the frequency too low you'll have a hole in your frequency response in between where the main speakers get down to and where the sub starts.

Setting levels between sub and main speakers depends on amplifier gain and driver efficiencies. Do it by ear and if you can get it to sound good that's fine. If not you really need a test tone CD and an SPL meter. This can also show you where your main speakers start to rolloff so it makes setting your sub crossover frequency easier.

I assume your bass control is like a tone control? If that's the case try 0 to start until the gain and crossover frequency sounds good and then increase bass if you feel like it.

You'd typically set gain and crossover frequency once and forget it once it's right and adjust bass from the head unit.

Be careful of having high gain/high bass levels set and playing low tones on a test CD. Unless your sub has a high pass filter set at an appropriate point where your port unloads (say 20 - 25Hz) you can get very high cone excuresion and damage your driver.

Normal music typically doesn't have program material down that low, but most test tone CDs go down to 20Hz.

Mikel