[BR3W CITY]

I suppose if they were wired together in a mono setup, you could run it like that for pure "boom". That setup doesn't look like its getting any more internal work, I think its just waiting on a front (plexi/acrylic etc). Thats just me judging by the finished edge on the front of the box.

I have run unbaffled/unseperated subs like that before, but with 4 subs I wouldn't run them like that again. I'm a fan of stereo subs from the start, for metal etc that can take advantage of the seperate channels.