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Polarity mystery: Can you help me solve it?

THE BACKGROUND: My speakers are Focal 1007be. They have a Linkwitz-Riley crossover with a 36 dB per octave slope. Because of that, the two drivers are wired with opposite polarity: the woofers are positive, the tweeters are negative.

WHAT I DID: At the advice of a friend with the same speakers, I inverted the polarity of the drivers, by simply reversing the red and black speaker wire leads to the terminals of both speakers, so that the speakers are still in phase with each other, but now the woofers are negative polarity and the tweeters are positive polarity.

WHAT HAPPENED: To my surprise, the sound improved! Specifically, image focus improved. The improvement can't be attributed to the preservation of the absolute phase of the recording, since the improvement was the same for many different recordings (some of which, presumably, preserve absolute phase, while others do not). And the improvement can't be attributed to the speakers being wired incorrectly at the factory, since the friend who suggested that I try this experiment owns the same speakers and experienced the exact same result. So I don't know what to attribute the improvement to.

Can anyone help with this mystery?
bryoncunningham
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almarg
9,670 posts
 
Hi Kirk,

Thanks for your characteristically knowledgeable response.

However, I think you may have misread or misinterpreted some of the earlier posts. As I understand it, Bryon has done nothing internally within the speakers. All he has done is to interchange red and black at the external terminals of each speaker, and also the sub, thereby inverting absolute phase. The result was improved imaging, which mystifyingly seems to occur consistently on a very wide selection of recordings, presumably encompassing some recordings that are absolute phase correct, some recordings that are inverted, and some recordings that are a random mix of phasings for the different instruments and/or voices that are present.

Given that, I'm not sure that the theory you have offered is applicable.

Best regards,
-- Al
bryoncunningham OP
890 posts
 
Kirkus - What do you think of Al's last post? Can the driver/crossover/cabinet interaction theory explain the improvement I experienced across all recordings, regardless of their absolute polarity?

Still confused...
rleff
1,065 posts
 
Got any test equipment like a o scope;if so I would put channel one on the input of speaker and then input a ac sine wave signal and look at the other drivers vs the input signal to see if the signal at the driver itself tracks with the input or is inverted;also I would use different frequencies and amplitudes.
bryoncunningham OP
890 posts
 
Rleff - No test equipment, unfortunately. I'm just a simple audiophile. :)
rleff
1,065 posts
 
Have you used any test cd's with phase test signals to try and help you understand this situation?
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