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An "Absolute Test" for audibility of "Absolute Polarity"

Posted by PeAK (A) on March 11, 2007 at 11:53:45

(Note: Please refrain from replying until you have done this test...that doesn't mean NO, though...if you cannot help yourself, just be to the point.)

For the record, if i swap the reverse the connections of both speakers, i can hear one condition/polarity sound "better". Some have called this "Absolute Polarity". Some claim that something else has changed, instead, giving rise to this audible difference. For now we will not pursue this "something else".

Today, it is possible to rip a .wav file using EAC that can be subsequently edited using the built-in sound editor ("process wave" function) to "flip" the polarity. I would argue that this is the "purest" experiment to test the audibility of ABSOLUTE POLARITY in that it changes only the polarity and nothing else.

Because it is/can a "subtle" aspect on some systems, here is a low pressure technique to see if you can hear it:

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Creating a Absolute Polarity Test CD

1. Rip a simply miked piece of music like Chessky's "Spanish Harlem" sung by Rebecca Pidgeon to a .wav file
   
2. Edited this file ("Tools->Process Wave" function) by highlighting both channels of the entire track (i.e. "Edit->Select ALL").
   
3. Invert the polarity of both channels (i.e. "Process Selection->Invert") and save it under a different file name by appending a suffix "i" to the original name. So Harlem.wav becomes Harlemi.wav . Exit the sound editor and you are ready to burn a CD composed of 10 tracks from these two files

4. Open the layout menu ("Tools->Write CD-R") and define the 1st song as Harlem.wav (i.e. "Layout->Append Files as New Track").
   
5. For the second track, define the "flipped" version Harlemi.wav in a similar way to the 1st track.
   
6. Now we will repeat the above process 5 times so that every odd track is Harlem.wav and every odd track is Harlemi.wav for a total of 10 tracks. You can do more tracks, if you like.

   Burn the CD by invoking "CD-R -> Write CD"
   

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Testing for Audibility of Absolute Polarity
You now have in you possesion a CD that only changes absolute polarity only by flipping the data using the high precision of your computer. To test for absolute polarity:

1. Cover up the "track display" and put the CD in the player and press play
   
2. Go out of the room or outside and work on something for a while.
   
3. Come back in and listen to 3 successive tracks from your test CD
   
4. Recall that one should sound a little better (or worse) than the previous cut. The third track (from when you started listening) will confirm your decision. Take a look at the track number (under the covered display) and note it for future reference.
   
5. Start the CD from track 1 and go into another room to work on something else (like read a book). At some point, the music will just draw you back into the other room with the system playing. Listening further, into the next track, there should be a "letdown" if the existence of "absolute polarity" exists. Take note of the track number.

6. Report back here with your results or with any modification to the above procedure

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My personal results are that I hear it readily with the polarity reversal at the speaker leads but I do not hear differences using this test CD. Your system, like your car, may have variable mileage using this test. I'm all ears.

P.S. On the "Spanish Harlem" cut, there is a readily identifiable timbre in Rebecca Pidgeon's voice and in a violin that comes in about 1/3 of the way in. The plucked "Bass" has a definite low frequency weight and defintion. Last, the castanets are a difficult test on the resolution of your entire chain.

cheers,
PeAK

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