where can I buy one in the vancouver area?
the external ones like the fmod ones.

thanks
Steve

[ September 18, 2005, 11:24 AM: Message edited by: bigsliks ]

Subsonic filter you may have trouble finding, unless it's not labled right, however you'd have a better chance of finding an "Infrasonic" filter.
I can order one for you..,but why do you need one?

Infrasonic(mistakenly called subsonic) filters were designed to eliminate the problems caused by warped vinyl LP's (that's analog discs to some of you), and were typically set at 15Hz, because there is no musical instrument that can go below that, except a synthesizer.
Are your woofers oscillating ?

F-Mods are a must with any ported sub. Better power handling, tighter, more defined lows, and less "Pppluck".

Technically, the are just a high pass filter, set at 20 or 30hz.
Pay attention to the direction they are installed, as it does matter. Male end goes towards the amp!
Try Harrison Labs. http://www.hlabs.com/products/crossover/

They make several types, includimg a new adjustable model, and are not that expensive, considering how much improvement they provide.

[ September 21, 2005, 05:29 AM: Message edited by: Car Trek ]

I disagree, I have been using ported boxes for 16 years and have never used a subsonic filter.

Ok.....You've never tried it, so it's not needed.

Try one for a week, then remove it, and see how long you can last without it.
I've been selling 'em since the 90's with an unconditional guarantee....If you don't like it, I'll buy it back.
Never had one set returned yet.

I have tried them, I never needed them. Of course I usually tune my system around 30Hz, and I don't listen to alot of cannon blasts or thunderstorm recordings.

I find they're good for a few extra dB from the amp, as they filter out the inaudible low frequency content that does nothing but push the woofers around. You can visibly notice a large decrease in cone excursion after plugging a set in.
Much in the same way that a HPF on a deck lets it play much louder without distortion, the 20hz HPF will free up wasted power, and also clean up the "doppler" distortion.
A 50hz tone played from a cone moving an inch at 20 cyles will not sound as detailed as it could.

My experience tho, is that most people can't percieve the improvement immediately, but after getting used to it for a week or so, will immediately notice the loss after removing them.

"Don't like it" and "Not entirely needed" are completely different things though.

How many of these people actually know how to tell if the filter is working or not?

It could almost be a placebo type effect where they THINK it's helping them out, even though they don't listen to any music below 30hz.

*edit... see what happens when I get distracted and take to long to push "send" :D

[ September 19, 2005, 12:04 PM: Message edited by: JordyO ]

I generally use an infrasonic filter to save amplifier power. I am never concerned with the performance of my vented boxes. Built and tuned properly, it really is not much of an issue - well unless one likes to listen to heart modulating sine tones all day long.

If there is no information on the disc below 30 Hz a subsonic filter will do nothing.