Liam when you say bridge, I hope you're referring to wiring. You can combine the 2 subs by wiring them in parallel or in series, depending on your amp. If the subs are DVC and your amp supports 1ohm load, then use the parallel mode. If however, your amp only supports 2ohms, then you better wish the subs are SVC. Read up on SVC and DVC on the internet.