Following all before I'll try to be simple for you. I asume you want to ensure your system will correctly reproduce a recording which is 'in correct phase'. If I were helping you confirm this we would 1st play and carefully listen to a CD recording- that is known to yield correct sound when played through a system with correct setup-, paying attention to detail and clarity, dynamic swing and bass response and soundstage. We would then reverse the leads on back of each speaker and listen again. Hopefully we will clearly hear and agree that one way sounds better- clearer, more detailed, less sibilance, more exciting & fun to listen to- than the other. Obviously the way that sounds better is the way the leads should stay. I would use a recent "Reference Recordings" CD to do this as (Keith Johnson is respected for being fussy about sound) I know his recent recordings are correct. If you use a TT we would do the same, with a Ref Recordings record -but switch the leads at your cartridge -since we have already determined what sounds correct for CD. Again the leads will be left where they sound best. As far as Radio-don't worry about it. It is true that recordings are not all in correct phase, and I have also found that even radio stations are not all correctly set up, so it is not possible to have radio consistently correct-even if you use just one station. Others have commented on the benefit of a pre amp that will allow for switching phase; and it is quite a benefit particularly for fussy listeners of classical music where the recordings are usually much longer than rock,jazz,EZ listening. Please let me know if this is helpful: or not.