I agree with the others. Put the EP175 in use with the den or the exercise room. You would be throwing money away adding another EP175 for your main room. Does your HK receiver have pre-outs? You should consider dropping all the EMO stuff for the time being (the UMC-1 is a flawed pre-pro with considerable problems to begin with) and put that money to a better subwoofer. If your receiver has pre-outs, you can add external amps in the future.

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne