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Speaker polarity

post #1 of 10
Thread Starter 
Does it make sense to talk about speaker polarity for a complete speaker (Woofer + Tweeter)?

I've just setup my 15" + horn (my LCR's in a surround setup), by using Smaart and phase aligning the two drivers. For the phase to align around the x-over, I had to invert the polarity of the horn-driver, so the woofer has positive polarity and the horn has negative. But what does this mean for the "complete" speaker?

I would think, that it is only important what the polarity of the woofer is, as it is crossed over to the subs (which again has positive polarity).

What worries me is, that my surround speakers have positive polarity, so if the horns on my LCRs are inverted and my surround speakers have positive polarity, will this result in any issues?

I hope my post makes sense - always difficult to describe these things

And I forgot to mention: All crossover is active.
post #2 of 10
you've got it right.

if the tweeter and the woofer are wired out of accoustic phase, they will create a suckout in the frequency response at the crossover point. actually, one way to tune active speakers is to try to maximize that suckout, then flip the polarity 180 degrees, so you will have near perfect summation at the crossover point at least.

the same applies to your subs. if the phase from the main to the sub is wrong, you will get a suckout at the crossover point, but it is much more difficult to see because of room modes muddying up the response.

it is quite common for two way speakers to have the top inverted from the bottom.
post #3 of 10
Thread Starter 
Cool. I was a little worried because I got the best results by inverting the phase. But as you say, its not uncommon to do. This is the phase response if anyone is interested:



Matches perfectly around 820hz which is the crossover.

I tried playing pink noise in both my center and one of my surrounds (the surrounds are "normal" speakers without any active crossover) and there are no problems with the horn from the center being inverted. If I invert the surround speaker, nulls appear on the measurements. (RTA for this little test).

The same test is a success when doing it for sub and center.

I love it when everything works out perfectly

EDIT: Sorry for the very large image... Cant seem to find the tag which sets a custom width...
post #4 of 10
Thread Starter 
Double post...
post #5 of 10
looks good. just out of curiosity, what drivers/horns are you running?
post #6 of 10
Thread Starter 
The speakers consist of JBL 4722-HF and i think the LF enclosure is called JBL 5642 (EDIT: It's 5641. The bottom section of the JBL 3731 speaker). Contains a single 2226h driver. Crossed over to two 4645c subs. I think its an amazing system. As long as you dont force the horn to play above 15-16khz...
post #7 of 10
What order and type of filters are you using for the MF/HF? A BW2 will require one section having inverted polarity to provide flat xover region response.
post #8 of 10
Thread Starter 
Quote:
Originally Posted by A9X-308 View Post

What order and type of filters are you using for the MF/HF? A BW2 will require one section having inverted polarity to provide flat xover region response.

I'm using LR4. I know this does not affect polarity, but the only way I could get the phase trace to match (using the lowest delay) was to flip the horn.
post #9 of 10
"The speakers consist of JBL 4722-HF and i think the LF enclosure is called JBL 5642. Contains a single 2226h driver. Crossed over to two 4645c subs. I think its an amazing system."

:-) damn, nice.

jbl pro may have a suggested crossover configuration for your setup, but it appears that you are doing just fine on your own.
post #10 of 10
Thread Starter 
Quote:
Originally Posted by LTD02 View Post

"The speakers consist of JBL 4722-HF and i think the LF enclosure is called JBL 5642. Contains a single 2226h driver. Crossed over to two 4645c subs. I think its an amazing system."

:-) damn, nice.

jbl pro may have a suggested crossover configuration for your setup, but it appears that you are doing just fine on your own.

Thanks Actually, the two components I am using are not a "stock speaker", so no configurations are available. The stock model (JBL 4722) has two 15" drivers (lower quality than the 2226H) which would overkill in my room! My own findings about the crossover is pretty close to 4722 config. They switch polairty too but I have longer delay than they have - but as my speakers are placed rather high, it makes sense.
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