Audio Speaker Polarity -- How do you check?
 

I have a 97 base with an aftermarket Sony Xplod cd player. In the door were some old speakers that did not work and the wires were not marked as to positive and negative. Aftermarket, not original, I assume. I bought some Sony Xplod matching speakers for the door. Once installed, it does not seem to matter which way the wires are connected. In the past, if you wired them wrong, it would be obvious. In this case, the speakers sound good either way.

There must be a way to check the polarity without pulling the cd unit out of the dash. The wires in the car door are probably aftermarket as well. The passenger side has a red wire and a plain wire. The driver side has a plain wire and a blue wire. Any ideas? I am getting a buzz out of my right dash speaker, but that is my next job. The speaker buzzes no matter the connections on the door speakers.

Thoughts?

Thanks.

Bradster

It doesnt really matter :)

Out of phase speakers definitely DO matter. If they are out of phase, one speaker cone is moving in when another is moving out. That causes a diffused sound image, and the low end (bass) is canceled out.

If you can see or feel the speaker cone, you can momentarily touch a 9 volt battery to the speaker terminals or wires. Notice which wire or terminal makes the cone move out when touched to the positive battery lead, and you've figured out which wire or speaker terminal is positive on your speakers and aftermarket wires.

Now if you can make sure that all the speakers are wired so that the positive amplifier out is hooked to the positive speaker terminal, they'll all be in phase, and will sound much better.

If they are all positive to positive, or all are positive to negative, you're OK. If some are positive to positive, and one, or some are positive to negative (out of phase), that's bad.

Thanks. Does the CD player need to be on for this test? Of course, the new speakers are marked positive and negative, I just don't know how it is wired at the back of the CD player unit. If I connect the battery to the wires, won't I have to perform the test where I connected the wires? Otherwise I assume it would test correctly at the speaker terminals

Thanks!

Ideally, you'd disconnect the wires at the rear of the CD player and test from there all the way out to the speakers. I wouldn't test with the wires still attached, as it may harm the CD player's output.

Thanks Jack. I appreciate your taking the time to respond.

Bradster