So I bought two 10" speakers from SLM to replace a couple of older ones in an Ampeg 810. I installed both with a close eye on the wiring configuration to match the previous other two. After I put them both in, one of the new speakers proved to be out of phase with the rest of the other 7 - but I popped the old one back in to double check, and it was fine. Is it possible to have gotten a speaker that was manufactured with reverse phase? Does this matter for a cabinet that isn't ported? If I switch the wiring on this one speaker, it switches the phase for the rest of the series (half of the cabinet), so would the best option be to place this particular speaker at the end of the series?