I've been browsing these forums ever since back in the day when I built my 36x36 Wicked One box, and sadly I blew one of my el cheapo MTX drivers in it.  I just built the box and slapped those bad boys in and away I went, but now the Rockford Fosgate P3D210's that I bought to replace them require a smaller box volume although ironically being much much bigger themselves.  I've calculated the 4th order bandpass volume requirements to be .424 ft^3 front and .628 ft^3 rear.  Now, I've read enough topics and the directions to know that I can change the rear chamber to whatever it needs, but what should I do about the compression chamber?  I'm not convinced I need to take away half a cube of volume since this isn't really a true bandpass design because of the horn and not port.  I've heard both ways to change it and just leave it be.

Here are the specs:
Qts: .5
Vas: .865 ft^3
Fs: 27 hz
F3: 26.5 hz
Calculated tuning: 41.63hz

If I plug in the current ~1 ft^3 front chamber and calculated rear chamber into WinISD, I get the nastiest peak ever, like 6 dB.  Is it really going to do that or is there more physics at play here than I understand?  Any answers would be appreciated.  ;D

I am not sure but I typical shot for the ported chamber to be ¾ the size of whatever the seal chamber calls for or as close as possible. I find the enclosures programs to work quite well but do not always represent the actually response of certain type enclosures. For instances the Half-Wedge builds look terrible on paper but in person are very impressive. I would be tempted to go on and install the Rockford and see if you like how they sound without any adjustment.

You might be surprised!!!


HT-EXT