I did a room family remodel and surround speaker re-wiring while my DD receiver is in the shop. Ran the wires under the carpet with some flat 16 gauge wire and afterwards did a continuity check to make sure the wires were labeled correctly. So I hook them up to a small stereo receiver I have and the sound is poor! It sounds like only one speaker is working, and when I get right in front of the one that seems incorrect there is very little sound and no bass. (there is no balance control on this cheap receiver BTW, but it works right in my bedroom so I do not think it is the receiver) So I then reverse the wires on one speaker, and voila the sound is full and both speakers are making what my ears tell me is a correct full spectrum sound with good balanced bass. So I do the continuity check again, and the results are the same, the wires are marked correctly. So why does is sound _much_ better when it appears that they are wired out of phase?