Hooking up Radio Speakers
 

You can get the speakers in phase just by using your ears if your
hearing is ok. Hook up the speakers so that they are connected in the
same way. Place the speakers so that they are about ten feet apart and
place your head so that it is half-waybetween the two speakers. Tune in
a music station or source and adjust the balance control so that the
seakers are putting out equal sound. Move your head toward one speaker
and back to the other one. If the speakers are in phase there will be a
smooth transition of sound from left to right; if they are not, the
sound will seem to jump from one speaker to another and you will feel a
strange sensation in your head when the out-of-phase signals are
opposing one another when you are exactly in the middle of the sound
sources. Another clue lies in the bass response. When both speakers are
pushing or pulling in phase, the bass response will be srong. When they
are out of phase, the bass response will be noticeably weaker as one
speaker sucks while the other blows. You will have to reverse one pair
of speaker wires to see which hookup produces the correct sound.
Purists will insist that the speakers should be hooked up so that the
positive pulse makes the speaker cone move forward, but in acual
practice I have never found it to make any difference, as long as the
cones nove in unison.