the speaker can move inward and still be considered in phase. don't be to concerned with wich is plus or wich is minus on mids and highs, best thing to do is hook them up and listen, then switch them around and listen again, decide on wich sounds better to your ears and go with it. depending on pathlengths to the listner a speaker that is wired in phase according to the + and - on the speaker, can hit your ears out of phase, most installers will play with the polarity accordingly, it's not that uncommon to find a guy running a componet set with say the passenger door mid in reverse polarity then the tweeter. now when your dealing with subwoofers, polarity is allot more important. u can still reverse the phase, but the polarity of both sub woofers must match each other or cancelation will occur.