Ran a box design through WinISD and wanted some input.

This is for 4 E8 8inch subs. It is a three chambered enclosure, each outside enclosure is 1 cubic foot tuned to 70 hertz. The inside enclosure is 2 cubic feet and is tuned to 40 hertz. The woofers will be mounted magnet end in the 1 cubic foot side two woofers per the 1 cubic foot side firing into the 2 cubic foot portion. This is for my kid who listens to mostly rap. Powering this will be a SAE1000d. A subsonic filter will be used to keep over excursion down. The graph on WinISD looks impressive in an open air environment.

Any reason to not utilise this box design?

6th order ?

Would be loud - for only rap it should be fine.

Group delay is going to be very high so it may not sound great on more "SQ" type music.

Yeah I believe it is termed 6th order though I always called it a dual relex bandpass. It's for a 16 year old kid. We were going to buy a box, but he wanted to build one with me. Stepdad/stepson bonding and all that. Plus I figure its a good learning experience. Figure when he gets tired of the sound we can always do a 2 cubed ported low. The output is high but really flat in its passband.