This may be stating the obvious here but watch your power output ratings on the amp when you are "sharing" a channel with speakers in parallel and going two ohm. If you have 2 speakers at 60 watts RMS each on a single channel, then you'll want that one channel of the amp to be able to put out 120watts+ at 2ohm to properly feed both speakers. 'Tis better to overpower speakers than underpower them I've learned. This is also where the suggestion for the 2-channel amp for your tower came from.