Need some opinions for alternate boxes for TC2+ 15" subwoofer

[boogs]

Hi All

At the moment i'm using 2 TC2+ 15" SVC subs, each in a sealed cabinet of about 4 cubic feet. The bass is good but i'd like a wee bit more. I've modelled the subs in a vented enclosure but i'm concerned about sq and possible excursion issues with the 400 watts each sub will receive (Adcom 585LE driving).

Here are the posted specs:

Qts 0.368
Qes 0.398
Qms 4.803
Fs (Hz) 17.7
Res (Ohms) 3.1
Le at 1kHz (mH) 2.6
Effective Diameter (m) 0.330
Vas (liters) 357.2
Mms (g) 233.8
Cms (mm/N) 0.348
BL (N/A) 14.20
SPL (dBSPL @ 1W @ 1m) 88.9
Rated Power (Watts RMS) 400
Xmax (mm one-way) 18.1

As always, cabinet size is an issue (WAF). Should i re-design as ported or just make do for now?

Oh, the subs are primarily for HT use although i watch a lot of DVD concert footage as well.

thanks!!

Scott