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Speaker Phase Question

2string1

2string1

Super Member
Can I check the phasing of my speakers with a 9 volt battery or will that do harm to the crossovers and tweeters? I have all speaker wires in the correct position but for some reason my system sounds better when I switch the phasing switch to the on position. I'm thinking the connections are wrong in the cabs. Fisher 500B and JBL Apollo C51's
 
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9V is pretty steep. 1.5V "D" size battery will do just fine for looking to see if the cones move in or out. That will work for the woofers, but most likely not for the mid and tweeter because they probably have capacitors wired in series that will block the DC signal from those drivers.
 
2string1 said:
Can I check the phasing of my speakers with a 9 volt battery or will that do harm to the crossovers and tweeters? I have all speaker wires in the correct position but for some reason my system sounds better when I switch the phasing switch to the on position. I'm thinking the connections are wrong in the cabs. Fisher 500B and JBL Apollo C51's
Click to expand...

As the previous post said, a 1.5 will do the trick - but I think you answered your own question. If the system sounds better with the phase switch set to on (not quite sure what that means), then leave it that way. You wouldn't see any cone movement in tweeters anyway, as you would in the woofs. Besides, some designs intentionally wire the tweeters out of phase with the woofers for internal phase alignment. As long as each woofer moves the same way, you're OK.
 
OK I check them with a 1.5 volt... positive to positive... negative to negative on the battery and speakers. The cone moves in on both speakers. I thought they should move out.
 
Anybody know if this is right. My system is all disconnected and I would like to put it back together.
 
Some JBL's were wired out of phase and some had a backwards wiring convention. You'll need the product literature. I think it's downloadable at Lansing Heritage.
 
What about the cone which way should it be going when testing with the battery or does it matter as long as they both move in the same direction.
Lansing Heritage will let me log in but won't let me post.
 
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Indeedy. Over at LH there is my thread/post regarding the L 46's I rebuilt, surrounds and crossovers -- discovered the schematic, twisted my mind into a pretzel due to the different tweeters i used and totally unknown to me that JBL used reverse polarity on many models. I just wanted the 46's to be in synch with the L112's I was using. IIRC there is (somewhere) maybe my posts, not sure, at LH a list of the models that used this phase reversal. On mine I took a 1.5 v AA bat. positive side to pos (designated) post on the woofer and cone retracted. At LH even though you may not yet be able to post, you can search the various threads/posts. desull
 
Thanks,just got off the phone with a vintage speaker repair person and he said JBL did some weird things back then. Red is negative and black is positive. I switch the wires around and everything seems good so far. Speakers are now pushing air rather then pull in. I will do some searches on LH and read up on this a little more. Thanks.
 
I have a pair of JBL L80t's that are reversed like that. With just two speakers it wouldn't really matter, but mine are used in a 5.1 setup with 3 subs, so in my case it does matter. I've thought of reversing the speaker leads inside the speaker at the binding posts, just because the reversed wiring sort of irritates me, although if you know how they are, it's not a big deal really.
 
2string1 your post reminds me of a newbie parent going all paranoid over his baby if it has a fever or not. LOL :D

Can't blame you with those Apollos... wonderfull
 
Well I've had these speakers for sometime now(not newborns) and was reading up on the Fisher 500B. It has a phase switch on the back and I had to use it in the on position which is wrong according to the manual. So hence the questions. When I tested the phasing with a battery there where sucking in air rather then popping out. After talking to several people about this they say they should move outward not inward to get the best bass out of them. I reversed the cable on the speaker side and so far I'm hearing an improvement. Much cleaner open sound.
 
I always thought it was the same to connect the speakers in-phase or phase reversed, as both speakers were connected the same way... (talking about the whole speaker, not individual drivers and crossover)

I've read that the signal is an AC signal, so there is no "+" and "-" really... But I'm not an expert.

The usual battery test should move forward the woofer when connecting + of the battery to the woofer "+" (when the woofer is connected phase-reversed, you are connecting the + to the woofer "-" ...so you need the crossover schematic to check that)
 
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I've reconed/refoamed many JBL woofers. Some have their terminals marked with a red dot next to the terminal which clearly causes the cone to 'suck in' when a + signal is attached there. This is contrary to what is the case for most other woofers where the + signal causes the cone to move out when attached to the red dot terminal connection at the side of the woofer.

So, it's evident JBL did this by design. Exactly why? Well, if Zilch was still around, he would provide an explanation. :sigh:
 
Do you think JBL designed these cabs around having the cones move in or did they just make black positive and red negative? Because if you wire them in the conventional way the speaker go in. I have the positive on the amp going to the black on the speakers and they never sounded better. The cones move out now on the thump...
 
If you take any two speakers and play a simple sine wave through both of them at the same time you should be able to tell by ear if they're in phase.

To see what I mean, do an experiment with the simplest case, identical speakers at low volume in an area where you don't get much room reflection. When they're in phase the sound will appear to be centered between the speakers and bass frequencies will be strong. When they're out of phase the sound will appear to come from the sides and bass frequencies will be noticeably weaker.

Keep in mind that different crossover configurations will cause different phase errors. That's why some drivers are intentionally wired out of phase.
 
If you have an iphone, there is a free app that you can use to test speaker polarity. It's called JL Audio Tools (no affiliation). There are probably other apps for it too. You just have to download a "pop" audio file (the app tells you where to get it) that plays an asymmetric audio wave. It sounds a little like hands clapping. Then you can hold your phone's mic up to each component and find out which polarity it has. A quick test with my EPI 202's reveals that all of the woofers are wired for positive polarity and the tweeters are negative polarity--hopefully by design.

I also tested a pair of Monsoon planar speakers and they tested + from the front and - from behind, so this makes me think this app really works. It's not one of those phony apps like the ghost detector or the zit remover.

Just to clarify, it does NOT tell you directly if your speakers are out of phase but it tells you the ABSOLUTE polarity of each speaker, or speaker component. If the speakers have opposite polarities, then they are out of phase.

It also has cool stuff like an SPL meter and spectrum analyzer, although who knows how linear its response is. Still, its fun to play with.

I promise I am not affiliated with this app or its developers. I just think it's pretty neat especially since it's free... of course they want you to pay to get more features.
 
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Thanks for the links. I don't see my model listed but i'm assuming I have a negative transducer. When wired positive on the amp to the red terminal on the speaker my cone go in. I prefer the sound when wired positive to the black on the speaker.The speaker goes out. There is more bass when wired positive to red but it mushy to me. They say more bass means it's in phase but I'm not sure if I like the bass I'm hearing. I need someone else to listen to my system, I'm getting cornfused....I also have a phase switch on the back of my amp which doesn't help... Oh boy this is fun... Not... I just want to get it right.
 
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