That 4 cubes was for a single 15" according to JBL's specs, so I apologize for giving you the wrong dims. I'm trying to confirm with something written by JBL themselves as to what they recommend for the 12" ported. SE claims 2.25 cubes, but no tuning frequency. The box size will go down with a higher tuning. You can definitely tune it to 32 or 35Hz, it'll just affect how flat it plays throughout the 30s and low 40s. Also keep in mind that the W12GTi's Fs is already at 32Hz, so I'm not sure how the woofer will respond being tuned right at that point.
What were the enclosure dims and response, if you don't mind me asking? I'm fiercely considering a pair or even three GTis for a future build in a Tahoe, but still need storage space.
