Well I'm not too sure if that jbl is a monoblock amp or a two channel amp, but you can't bridge a monoblock amp. Its already one channel and only 1 channel. Most mono amps provide two sets of speaker outputs, but mono amps will "see" exactly the load put upon it(ie, 1 4ohm sub= amp at 4 ohms, 2 4 ohmn subs in parallel=2 ohms at amp). Now if you have a 2 channel amp, and you bridge the 2 channels into 1 channel, then the amp will "see" half of the load put upon it(2 4 ohm subs in parrallel= a 1 ohm load on the amp)ie. 2 4 ohm subs in parallel= 2 ohm load, now put that 2 ohm load on a bridged amp, amp sees half of 2 ohm which = a 1 ohm load. Dvc subs are great for many different wiring set ups, but better suited to multi-channel amps insted of mono class D amps(assuming the DVC's are 4 ohm each coil and class D amp is only 2 ohm stable)