2 Z623 systems from Logitech one sub stopped working so bought another sub in sub box. Can i use the old sub and wire them together as the subs are fine, just the amp went for 1. Not sure on the ohms could be 8. Will it work? The Z623 systems are all well and good when working, it does get loud but the amps are crap. Have i just answered my own question will i pop another amp?