# Determining tweeter polarity



## FoxPro5 (Feb 14, 2006)

I've always used a AA battery to check for polarity on mids and assume the same test works for tweeters also. 

Is there a better method? 

Is a AA ok to use for a tweet?


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## npdang (Jul 29, 2005)

I can't think of an easier method. Usually I just take an impulse response measurement.


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## FoxPro5 (Feb 14, 2006)

npdang said:


> I can't think of an easier method. Usually I just take an impulse response measurement.


Ok, thanks. I wasn't sure if a AA was too much for a tweeter.


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## joey_kev (Mar 12, 2006)

sorry for the noob question
but what is the purpose of checking polarity of speaker drivers?


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## B&K (Sep 20, 2005)

really just verifies that the little +/- labels were put on the right terminal. i have seen a few drivers where this isn't the case.


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## FoxPro5 (Feb 14, 2006)

Well I my case, the cup that holds the tweeter is marked but the tweeter itself is not. I removed the cup and now have no idea which is which. I don't want to have to guess if they are playing in phase with each other. Thus the solution is to check.


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## slow2.2sonoma (Jul 9, 2006)

tweeters have such limited xmus id think you wouldnt really be able to clearly see the movement anyways? id agree with npdang and just take the impulse response measurement.


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## slow2.2sonoma (Jul 9, 2006)

correct me if im wrong, but i think it'd be smarter to hook them up then reverse one or the other and see which sounds better because depending on your placement wiring one backwards may actually imporve the stage. but if you are using time delays then id just go ahead and wire everything correctly and let the time alignment take care of it all.


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## FoxPro5 (Feb 14, 2006)

First off all, the AA battery is enough to see it move. Problem solved!!

Second, I have no idea what an impulse response is...let alone how to measure it.

Third...like I said....I had NO IDEA which side is plus and which is minus. I understand phasing!! To phase correctly I have to know which phase they are playing in the first place. Thus the need to determine polarity!!


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## joey_kev (Mar 12, 2006)

so how do you use AA battery to test the polarity?


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## sqkev (Mar 7, 2005)

IMO, it really only matters when 2 tweeters are installed and one is out of phase. Or when installed with a mid and there is a null or peak.


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## Exalted512 (Jul 23, 2006)

joey_kev said:


> so how do you use AA battery to test the polarity?


put the speaker wire on the negative and positive side of the battery. The speaker will either move in or move out. If the speaker moves out, then the lead touching the positive side of the battery is positive and vice versa for the negative. If the speaker moves in, then the lead touching the positive side is negative and vice versa.
-Cody


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## FoxPro5 (Feb 14, 2006)

sqkev said:


> IMO, it really only matters when 2 tweeters are installed and one is out of phase. Or when installed with a mid and there is a null or peak.


Correct...but how would you know the phase if you did not know how they were wired in the first place? Good lord what have I started here


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## chad (Jun 30, 2005)

Exalted512 said:


> put the speaker wire on the negative and positive side of the battery. The speaker will either move in or move out. If the speaker moves out, then the lead touching the positive side of the battery is positive and vice versa for the negative. If the speaker moves in, then the lead touching the positive side is negative and vice versa.
> -Cody



Ahhh except for Some old Altec and most JBL Pro stuff  A positive impulse makes it move bakkids! Mr. Lancing made it hell for some of us! Go pop an old GTi series  SUPRISE! A JBL VGC Coil and basket on a re-designed cone.

Chad


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## FoxPro5 (Feb 14, 2006)

Well this is a Dynaudio MD100, sooooo.....


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## slow2.2sonoma (Jul 9, 2006)

ive never tested the polarity of a tweeter with a battery, but i was just thinking that since the tweeter doesnt move very much at all then it will be really hard to see whether the dome went in or out simply because the movement is so subtle...


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## Exalted512 (Jul 23, 2006)

its not that hard to tell, I have more trouble testing the polarity on my 3" DLS dome midrange than my 1" DLS tweeter
-Cody


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## sqkev (Mar 7, 2005)

B-Squad said:


> Correct...but how would you know the phase if you did not know how they were wired in the first place? Good lord what have I started here


I don't think you read into what I said.
With 1 tweeter playing, the only difference by reversing the polarity is the time arrival of the sound. When you install 2 tweeters with one out of phase with the other (both are from the same distance), you might hear a difference. 
When 2 tweeters and 2 mids wired together and one or 2 is out of phase (of the opposite driver), you will hear a difference.


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## evident (Apr 10, 2009)

npdang said:


> I can't think of an easier method. Usually I just take an impulse response measurement.


how do you do this? with a digital multimeter? what is the response supposed to look like?


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## chad (Jun 30, 2005)

Let me google that for you


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## falkenbd (Aug 16, 2008)

wow, super old thread bump.

an impulse response is done using a microphone and computer based RTA setup. (not a cheap mic) 

if you search you can find the threads on computer based RTA setups in the tutorials section.


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## 14642 (May 19, 2008)

Accurately measuring the impulse response of a tweeter isn't as easy as one might think. Use the battery. If it's relative phase, measure both tweeters together, reverse the polarity of one, measure again and compare the overall output--in phase will provide more output.


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## VP Electricity (Apr 11, 2009)

FoxPro5 said:


> Well this is a Dynaudio MD100, sooooo.....


I knew that when I read the original post - I've seen this movie


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## dashan (Apr 7, 2009)

FoxPro5 said:


> Well this is a Dynaudio MD100, sooooo.....


Could someone please verify how an MD100 and MD102 would move (which direction) when connect to a AA battery (+to+, -to-)? 

Thanks


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