I seen this box on ebay and was wondering how hard it would be to make one myself. and for fosgatefan, would this be a good box for my 2 punch subs. thanks

 

my bad here's the link http://cgi.ebay.com/ws/eBayISAPI.dll...category=14945

 

I'm not sure about the RF subs but you could check the RF web site to see if they will work in a ported box. There are a few things to consider when using a ported box. First you need to know what frequency the port is tuned to. Second based on the tuning frequency, you may need a subsonic filter. For example, if your box is tuned to 45Hz and you have some bass heavy music that goes down to 20Hz you will more than likely damage your speakers even at a moderate volume. When playing below the tuned frequency, the sub is unloaded and can bottom easily. Above the tuned frequency the port provides resistance to the sub.

Sealed boxes are best for beginners.

-Robert

 

That box is another one note wonder. Ported at 45 Hz with a small port relative to the displacement of the two subs. Tons of bass in the 40-50 Hz range. A simple ported box will always drop off faster than sealed below the tuning frequency. 12 dB per octave less output below tuning. It appears there was careful doctoring of the curves used. Or the user set up conditions that can't be recreated in your vehicle. The typical sized sedan has about 20 dB of gain at 20 Hz relative to anechoic mesurements. The ported box on that site i slikely to blow your subs without a 24 dB or better infrasonic filter at 35 - 40 Hz. Sub bass will be very unsatisfying.