OK, everybody calm down...this is merely a theoretical inquiry about using different amps into individual but identical speaker cabinets. First off, yes, I used the search function. Maybe I didn't word it properly, but I came up with nothing. If you know of a similar thread in the past, I'm sorry. Secondly, please refrain with any "why would you want to do that?" comments, as in "why would you want to use 15's instead of 10's", or "why would you want to drag all that iron around when you can just slip a class D Uberbomb 1000 into your gigbag?" I just do. Also, let's just assume that there's a 'not too bright but can lift heavy things' neighbor kid I can slip a 20 to to help me move stuff. AND, once again, this is just a theoretical discussion. I'm just trying to gain knowledge. So.... For simplicity's sake, I would have four identical textbook 1x15" TL cabs, each loaded with a 200 watt EVM 15-L. Laid on their sides, and stacked vertically(ports all on one side), there shouldn't be any speaker phase issues, correct? The four amps to be used would be: 1974 Marshall Super Bass(4x6550), Sunn Model-T, 1st generation(4x6550), Sound City 150B(4x6550), and Fender Studio Bass(chopped into head format, 6x6L6). Two heads each in two 'live-in' road cases. Which head to which cab in the stack will be determined later. A Voodoo Labs Amp selector switcher would be employed. Now, yes, I'm aware that there have been certain GUITAR amps with input and output phase quirks(the Vox AC30 has a channel whose inputs are out of phase with the other two, and I believe the Fender Super Reverb output is reverse phased; if I'm wrong, and if there are any other amps out there like that, please inform me). Now, assuming that the phase on all of my four amps(I actually do own all four of those)are proper, would there be any phase(or any other performance) issues from all this accumulated equipment(aside from potential power supply ground loops or potential shock problems)? Would the variety of tone stacks in play create any problems? That's kind of the reason for attempting this experiment, to 'layer' the different sounds of the various amps. Thanks in advance for any observations/knowledge.