Audio Systems: Connecting unlabeled speaker wires to a receiver, polarity, phase

Question
Good Evening.

I currently have an old Pioneer SX750 Receiver with 4 speakers.  Two of which came with the receiver some 35 years ago and two more recently purchased Bose outdoor speakers.  Well..after some recent remodeling, where I had to disconnect the speakers from the receiver; I forgot to label them...and now we have hardwood flooring covering the speaker wire...I have no idea how to reconnect the wires to the A & B inputs in the back of the receiver.

Can you help??

Answer
This is easy.
Just use a 9 volt battery and apply it (for a short burst) to the speaker wires. Professional installers seeking proper polarity call this procedure 'popping a speaker' since you only apply power long enough to see the speaker move. If the battery is held in place too long you can damage the speaker coil!!
Anyhow,
 If the speaker moves out of the box, the speaker lead hooked to the positive battery terminal IS the positive of the speaker.
If the speaker moves in, the speaker lead hooked to the negative terminal is the positive of the speaker.

Oh yes, one other thing.
Once the speakers are in proper phase, there should be a LOT more bass when the balance is centered than when it is all on one side. If you notice more bass when the balance is set on one side, one of the speakers is out of phase.

Jerry Mael
with AE since 1999