Why do I think I need this?: I don't think I need it, I just want it. I've read about other pb12 owners using a high pass on their sub channel for music and now I want to try it.
In that case 25 Hz is all you really need, so the Behringer crossover would do the trick.
Thank you, actually some place called Creative Sound Solutions has a B1 listed at $73CDN, that would fit my budget. A question though, would using something like this degrade the sound at all since it's another piece of gear in the chain?
No more than the Behringer would... Actually, the subwoofer channel is very forgiving. That's why the Behringer Feedback Destroyer, an equalizer you probably would not ever want to use for the main channels, works fine for subwoofers.
I also found this: PFMOD (Parametric Filter Module) HP-Sub for $40 (h t t p://store.hlabs.com/pk4/store.pl?view_product=12)
Does that seem like a good device? Might be a bit more work than the Reckhorn since you have to remove jumpers. The site also says it is passive and doesn't introduce any noise or distortion.
That one looks like a viable option as well. Only 12 dB/octave slope, but that's sufficient for what you want to do.
I don't understand what the "at 12db per octave" part means though. Could someone be so kind to explain?
It goes to how "fast" the signal attenuates. Basically, one octave when you're going up the frequency scale is double the starting point - e.g. 160 Hz is one octave above 80 Hz. Going down the frequency scale, one octave is half the starting point - e.g. 40 Hz is one octave below 80 Hz.
The slope is how far the signal drops one octave past the starting frequency. Using 80 Hz as the designated frequency, a 12 dB/octave slope means that at 40 Hz the signal has dropped 12 dB. So, if you played sine waves at those two frequencies and you measured 85 dB at 80 Hz, you would get a 73 dB reading at 40 Hz.
Most crossovers and HP filters these days use 24-dB slopes, which are much better for dividing between a sub and the mains. For HP filters, the most common use is to protect the sub from over driving (maxing out) below its tuning frequency. Naturally, a 24-dB slope would do a much better job at that than a 12-dB slope.
But for what you want, for music listening, all you're trying to do is attenuate the lowest frequencies so that they don't overwhelm and obscure the detail that might be present in the upper frequencies. So a 12 dB/octave slope will be fine.
Regards,
Wayne A. Pflughaupt
