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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
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?
kirkus
502 posts
 
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.
From this statement, my assumption was that you removed the woofers and tweeters from your loudspeaker cabinets, reversed the wiring on each of the drivers, and put the speakers back together. Is this correct?
gregm
3,405 posts
 
Kirkus, that was also my initial assumption --

Anyway, a 180d change can produce a relative suckout in the lower-mid area, whereby the perceived result is more clarity ion the upper register (=better imaging) and a more pronounced upper bass region.
jea48
4,453 posts
 
Kirkus,

That is the way I read the OP at first as well. But through later responses from Bryoncunningham I believe he just reversed the speaker cable leads at each of the box speaker terminals.


Anyway, a 180d change can produce a relative suckout in the lower-mid area, whereby the perceived result is more clarity ion the upper register (=better imaging) and a more pronounced upper bass region.
02-24-10: Gregm

Gregm,

What if instead of reversing the polarity at the box speaker terminals Bryoncunningham pulled the midrange/hi-frequency driver and reversed the polarity there? Then reconnect the speaker cables from the amp to the speakers + to +, - to -.
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