I'm in the same boat. I have a single Empire that I purchased with plans to add a second one down the road. Now that option is off the table, so I am trying to pick a second sub that would allow me salvage my investment in the Empire.
HSU used to sell a "mid-bass module" that was intended to be placed near field, and coupled with a larger sub to handle the lower frequencies. I was wondering whether I could use the Empire (touted for its mid bass performance) in a similar manner, or whether that would just be a waste of a decent sub? Currently I have the Empire placed in the front left corner of the room, but could relocate directly next to the seating area. Then I could add a new sub to where the Empire now sits. I'm not sure exactly how you would "split" the bass frequencies between the two subs, as I believe the crossover for the Epik acts as a low pass filter, and so I am not sure how you would limit it to mid-bass duties. I guess you could use an in-line filter on the Empire to limit the lower frequencies, but don't know if that would cause any problems with Audessy (I am currently running MultEQ 32). Any ideas or suggestions would be appreciated. I may just have to bite the bullet and get a new sub, knowing that it may replace rather than supplement the Empire.
Incidentally, if anyone in the central or SW Florida area wants to either buy or sell a single empire, I would be more than happy to either double down on a second empire or sell my existing one and start from scratch. Just PM me with any interest.