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Discussion Starter #1 (Edited)
Hello everyone

I am in the process of Audyssey calibration. After firsts measurement Audyssey reported inverted polarity of LCR speakers. I checked all connections and were OK. This led me to take some measurements to check IR polarity. They indeed looks inverted, at least for me, so I reversed LCR cables and measured again. Now, can anyone confirm that all speakers polarity are OK, especially subwoofer. Note: IR delays and levels were altered for better visibility. Thank you.

LCR.jpg

SURR.jpg

SUB.jpg
 

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The TWs are all now positive polarity. The midwoofers also appear to positive polarity, but it is impossible to be sure given these IR graphs.

These graphs say nothing of the XO handoff from the SWs to the mains. Audyssey normally does a very good job however so following their process often leads to good results.

You may want to look at the SPL curve and if it looks good in the XO range (smooth and near the level of the rest of the SPL response) then all is well. If there is a large sag or null in the XO range then the timing/distance may need adjusting. A room mode null in this range can make this range can complicate this analysis though. It can make correct timing appear to be wrong.
 

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Discussion Starter #3
Thanks for response. My intention was to check polarity only, so speakers were measured independently without XO applied. REW generator was connected directly to each channel power amp input.
 

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It's possible that one or more speakers were wired backwards (accidentally or intentionally) during manufacture... Not sure why anyone would do this, but it does happen sometimes. The easiest way I know of to check is with a AA battery. If + voltage on the RED terminal on each speaker displaces all cones in the same direction, then your polarities are all coherent. It doesn't particularly matter if that displacement is out or in, as long as they're all the same. Then if you need to invert polarity on one speaker or another for in-room response purposes, you're at least starting from a predictable place.

With a battery that small, you're also very unlikely to do any damage... but even so, it's best not to apply DC voltage for more than a moment. If you make a solid contact with one lead and just brush a terminal with the other, you'll be able to see the motion without risking any harm. You'll hear a click and the woofers will jump a bit. It also works with a 9V, but less is more if you can get away with it.
 
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