There will be no audible difference between one or two chambers. There are a couple of small advantages to having two smaller chambers, though. First, the wood that seperates the chambers will act as a brace that the bigger single box may not have (unless you add bracing). Second, having two chambers will protect the other speaker if one blows. If you had one chamber and one of the speakers blew, you would essentially have a ported box tuned to a middle to high bass freq which could cause your other sub to unload and possibly damage it.
