build a 12 inch variant, rather than the celestions use beyma lx60's, they are true monsters, have a 9mm x max , low qms, qes e.t.c
got a pair of wicked ones loaded with these and they are quite good, they try and play too low, we scaled the box up two inces in height and as a mod have scaled the horn throat back down to the 10 " size.
did a free party outdoors this weekend using a lx60 loaded wicked one and martin 215 (double 15 front loaded unfolded horn) as the bass stack, witha pari of peavey 15" and 1 tops for ease and simplicity.
it reinforced my opinion that those two boxes as a combo make and absolutely nails bass stack for everything from dub to acid techno, cranked it at the end and played some of the more mental tracks off 'go plastic' by squarepusher , there was a bit of tarp around the bass stacks in case of raing with 10" or so flapping around at the bottom under the wicked one, it was getting a 1000w and you could see every bass note in the tarp, the held 20-25hz notes were a joy to behold.
the lx60's make the wicked one a 1400w pa cab, my only reservation currently is that we angled the baffle to fit the 12's in and i dont like the possibility of uneaven pressure loading, the mk.2's are gonna be about 6 inches wider, have the same horn rate and possibly be tapered down to a 10" throat size from the mid line of the box, if ya get me?
might possibly make the backchamber a bit smaller to make the box play a little higher, seems to have about +3-6 db giain below 4-50 hz which is fine for a sub however were planning on using 2 direct radiating 12's with a horn loaded 8" and 1" comp driver mid top for a slimline 4 box 7k monster pa.
cant wait untill the mid tops are financed and constructed i assure thee it will be a nails pa.
also on a unrelated note, google orgonite, build some (its cheap and easy), put it on your speakers (just a lump on top of the cab)....observations please (seemed particuarly good on a death box)