I'm having some out-of-phase issues. I have two 4 Ohm cabs, so I use one head for each. I've been using a Y-cable to split the bass signal in two, then feeding each amp (using two G-K MB200), and that works fine. But when I use one MB200 and a TC electronic RH450 in the same fashion, they sound out of phase. I tried taking a line out from the RH450 to the input of the MB200, but that also yields and out of phase effect. I've been looking at splitter box (Whirwind) and Radial, but I can't seem to find a proper splitter. Can anybody offer a solution for this? Thanks!