Reversing Polarity -- Voodoo or Easy Tweak?


In a recent thread I noticed a comment about reversing polarity of speaker wires on both speakers which sparked one of my earliest audiophile memories.

On the liner or cover notes of Dave Grusin: Discovered Again on direct to disc vinyl, circa 1977, it too recommended reversing the polarity on BOTH speakers, for best sound.

Although my first system was a 25 WPC Technics receiver with Infinity Qa's and lousy speaker wire, I still remember getting very enthusiastic about reversing the polarity and wondering if it did anything.

Can anyone explain this and/or recommend if this is even worth the experiment?
cwlondon
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Herman

Excellent post!

Tvad

At the risk of oversimplifying things here:

If ONE speaker has + and - (it's polarity) reversed, then the system will be "out of phase".

And no offense , but no self respecting audiophile should need a test disc to hear this -- it creates a weird, vague image, and to my ears at least, a slightly disorienting, almost uncomfortable to the inner ear wandering sound.

When I sold hi fi during college, the owner of the store thought it would be amusing to demonstrate my lack of experience by asking my opinion on a system where he had wired the Acoustat speakers "out of phase". It took me about 15 seconds to hear this.

During the recording process, however, certain things might be recording about of phase to create weird imaging effects. In addition to Jimi Hendrix, I think Roger Waters Amused to Death is known for this type of demo.

My original question of course was

what happens?
and why do some recommend?

changing the polarity on BOTH speakers.

Although the "polarity" in this case changes, it does so on both speakers, the polarity remains consistent so the signal remains "in phase".

I think I am using these terms correctly now?
Cwlondon, I understood you in your first post. Few are stupid enough to wire one speaker out of phase with the other. Absolute polarity is a different matter. I wish I had an easy way to have switchable polarity, so that I had a choice, but I don't have. Even cheap digital players used to have this, but no longer. I am not about to change speaker leads for each cd or record.

In the past, on perhaps 10 percent of my records changing the absolute polarity made a great difference. On about 30 percent it made no difference.
The Grusin LP was recorded with the absolute polarity reversed. Shefield realized it after the fact and this is the reason for noting it on the cover. About half of the LPs and CDs have the polarity reversed. Some of the offenders are Mercury Living Presence, RCA Living Stereo, Capitol, MCA, Decca/London, DG and Warner. When your ear is trained to hear this, it will take about 3 second to pick up on it. I don't do vinyl anymore so it's easy for me to correct with the polarity switch on my Theta DAC. Then I mark the CD insert with a green (correct)or red (180 degrees)sharpie. A polarity switch on the preamp's remote would be even easier. Listen to a recording of Nat King Cole on Capitol both ways. There is a huge difference in these recordings and it's easy to hear. If you can't hear the difference, well...
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