I have a 12in subwoofer installed in mine. Sounds incredible. It makes for approx a 1.2cubic ft enclosure with dynamat, sealed acoustic suspension enclosure (no boomy ghetto sound, just tight acoustic bass) With the proper sub brings my f3 down to just under 20hz. Image Dynamics ID12 sub was made for such a sealed design.
The rest of the audio setup is beyond the scope of this thread, just letting you know what I did with my spare space.
I like the tent idea too! Looks good.