You can certainly try different settings. I would say that most of the time, when I have integrated two subs, I end up setting them pretty much the same. Of course, I may have to make some modification to the controls for both subs to make sure that the response is maintaining linearity. For example, subs can generally reinforce easily in the deeper bass than the mid-bass and as a result, you get a nice boost in the deeper bass frequencies. So you would use the EQ or the Q control functions to tame that down a little. In terms of performance, whenever you start adjusting the port configuration/EQ/Q settings, you're not only changing the response, but you're also changing the performance characteristics, especially with the port configuration. What ends up happening is that you may end up bottlenecking your sub system due to the setting on one sub. However, to your point on mid-bass and deeper bass separation, that is the main reason why we came up with the MBM series (now the EQ 2 mode on the ULS-15 Mk2). That allows you to use the ULS-15 MK2 in the mid-bass module mode so it can handle those frequencies for you and you can run the sub along with that with the crossover set to around 40-50 Hz. So that is a valid way of running a two sub system.