well i have 2 12 si bm's and a us amps md2d the new version so like 1700 or so and i also have a 15" mag to which im going to be installing soon just need the ho alt but they are pretty roomy
yeah I had a single 12 audiobahn quad voice coil 12 in mine on a mtx 1500d and later I had two lanzar dc 12's (old school when lanzar was still lanzar)...the audiobahn was firing forward into the cab and the lanzars were firing backwards toward the tail lights...the backwards firing setup was probably the best but the back deck raised up a good bit and probably held back a decent amount of spl...the stock 105 amp alt didnt really keep up even with a redtop optima and the other two amps I had for the highs turned off...so I can understand why you need a ho alt for your car...heck with all three amps on my headlights would dim alot with the system cranked up and that was while driving down the road reving at 4000 rpm!