Re: Do I need a new box???
The good; HDF is used over other materials.
(quoted from link from OP)
To achieve maximum performance, we recommend using an amp with "Bass Boost" and a 12 to 18 dB boost at 45 Hz with the crossover point at 90 Hz and down. With gains set correctly and "Bass Boost" turned on, your ProBox will deliver an awesome performance you'll want to show off to all your friends.
It doesn't mention internal bracing, so I doubt there is any and they don't mention material thickness so I'd agree it's probably 1/2"
edit again. the raw pic of the 'super bass' box does show ribbing.
Team Southern Bass