[Mike P.]

Your numbers are right. The ports displace .9 cu.ft. so the total internal volume needs to be 4.1 cu.ft. A 21 inch cube is 4.3 cu.ft. internal. Getting the ports in there will be fun! Remember that when using elbows the port length is determined through the center of the port. Post a build thread if you can. :T

 

[Mike P.]

No, that's 63 inches long for each port. A slot port 3" x 8" x 58" long would work as well. Air speed would be under 28 m/s with 700 watts input power. If you go with a slot port make sure to round over each end of the port as well as any corners.

 

[Mike P.]

Post #16 will give you an idea of what is involved with a power port.

http://www.hometheatershack.com/forums/funky-waves/10524-custom-re-xxx-subwoofer-build.html

 

[Mike P.]

I am powering this with a EP2500, so I am not sure what VC to get.....I might end up building another twin box/sub....

Get the dual 2 ohm coils so that either one or two subs can be wired for a 4 ohm load on each channel of the EP2500.

 

[Mike P.]

You must have read it wrong. At 1 khz it's 1200 watts into 2 ohms and 750 watts into 4 ohms, both channels driven.

 

[Mike P.]

Reckhorn B1 from Creative Sound Solutions. Unlike the E.D. eQ2, it's guaranteed to work with a pro amp.

 

[Mike P.]

No, that's the F1. You need the B1.

http://www.creativesound.ca/details.php?model=B-1

Here's moe information on the unit.

http://www.reckhorn.com/index.php?ln=en&prod=b1