D-MAN Posted August 15, 2005 Share Posted August 15, 2005 This is profoundly strange - I thought that I'd post this experience with trying out different woofers in my horns... 4 different pairs of woofers tried and only ONE pair that is not out-of-phase when wired correctly!!! The "correct" pair? Klipsch K33E's. All of the others (from 2 different manufacturers - one being Eminence) cancelled each other out when wired correctly (pos to +) in each horn. Believe me, there was no error in the wiring. I would naturally have assumed that it had to do with the actual room if it wasn't for the K33E's being "correct" in phase when wired "correctly". That is the clincher, and eliminates all other potential wiring mistakes! I have to ask, how is this possible? What are the chances of getting the voice coils wired "backwards" in manufacture? Is this widespread or just my luck? I am assuming that it is a condition with the drivers, not the room itself (that would be excessively and unexplainably weird). DM Quote Link to comment Share on other sites More sharing options...
BEC Posted August 15, 2005 Share Posted August 15, 2005 More likely the magnets are opposite. Easier for that to happen during manufactrure than voice coil being wrong. I have seen that on ceramic magnet tweeters. Hold two of them back to back. If the magnets are oriented the same, they should repel. Bob Quote Link to comment Share on other sites More sharing options...
D-MAN Posted August 15, 2005 Author Share Posted August 15, 2005 Bob, thank you - that makes sense! I was confused as to what could have been going on. But it makes one concerned about how many untested (in stereo)speakers are out there, put in the box and shipped. Until listened to in pairs (against each other), one would not actually know. Individually, each speaker sounds fine (it is actually hard to tell). I wonder how many people are listening to mismatched drivers right out of the box?! {edit} I'm going to do the back-to-back thing when I get home, and I'll post the results. DM Quote Link to comment Share on other sites More sharing options...
Malcolm Posted August 15, 2005 Share Posted August 15, 2005 I don't think there is an industry standard for polarity (whether the cone cones in or out when connected a particular way), but one would think that two speakers from the same manufacturer would be the same if the terminals are marked. Sounds like a quality control issue. Quote Link to comment Share on other sites More sharing options...
BEC Posted August 15, 2005 Share Posted August 15, 2005 An old EV spec says that when a positive signal is applied to the positive terminal, the result should be outward movement of the diaphragm or cone. I don't know how many manufacturers hold to that standard, but it seems a good place for all to be. Bob Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted August 15, 2005 Share Posted August 15, 2005 JBL sure doesn't. BLack is traditionally positive on their stuff, although I've heard that some of their new is conventional. Quote Link to comment Share on other sites More sharing options...
D-MAN Posted August 15, 2005 Author Share Posted August 15, 2005 I don't care as to which is which, as long as they are CONSISTENT from driver to driver. How many of us are going to open up a speaker cabinet one day, see wires apparently backwards on a driver and assume that they are wired wrong based on the other speaker in the pair? Messy, messy. DM Quote Link to comment Share on other sites More sharing options...
Malcolm Posted August 15, 2005 Share Posted August 15, 2005 How would you know which one was wired right (on a non-Klipsch speaker) if one went in on a positive signal and one went out? The only difference between a Klipsch Type D network and a Type E network is woofer phase. After releasing Heresys with 8 ohm woofers and the Type D network, Klipsch decided the speaker sounded better with the woofer phase reversed. Quote Link to comment Share on other sites More sharing options...
djk Posted August 16, 2005 Share Posted August 16, 2005 Woofers with ceramic magnets are charged after they are assembled. JBL (and others) do what they want to do. Use a battery if you really want to know. Quote Link to comment Share on other sites More sharing options...
CaptnBob Posted August 17, 2005 Share Posted August 17, 2005 According to legend, Jim Lansing was so annoyed at the people at Altec when he left he didn't want to have ANYTHING the way Altec did. So instead of a positive voltage making the woofer jump away from the magnet, he had his reversed. By the time he was no longer on the scene, it was too late to change things. Quote Link to comment Share on other sites More sharing options...
djk Posted August 18, 2005 Share Posted August 18, 2005 Lansing didn't 'leave', he sold his interest in the company and signed a 5 year non-compete. The polarity fiasco came from the old L1 L2 convention that made a difference in absolute polarity with different driver construction. Altec had problems with this too, later they standardized on red positive to produce positive pressure. Early drivers labeled L1 as red and produce negative pressure with positive voltage on the red terminal. Quote Link to comment Share on other sites More sharing options...
WMcD Posted August 22, 2005 Share Posted August 22, 2005 I agree that the convention is that whatever makes the diaphragm move away from the magnet is the "plus". Also it is convention that red is positive and black is negative. However, if only one terminal is marked by paint, it is most likely the positive, regardless of color. I was thinking about how to check for a reversed magnet without taking the units apart. My thougth is that a compass will react differently when brought near the woofer. This might also indicate whether a speaker has sheilded drivers. Being a bit flip: CRTs react to the magnetic field of unshielded drivers. So maybe a CRT would warp colors differently in reaction to a reversed magnet. Smile. Gil Quote Link to comment Share on other sites More sharing options...
formica Posted August 22, 2005 Share Posted August 22, 2005 ---------------- On 8/15/2005 3:29:45 PM BEC wrote: An old EV spec says that when a positive signal is applied to the positive terminal, the result should be outward movement of the diaphragm or cone. I don't know how many manufacturers hold to that standard, but it seems a good place for all to be. ---------------- Most of the recent drivers I've played with all seem to adhere to that... but I usually test them with a AA battery before closing up an install. ---------------- On 8/15/2005 2:17:44 PM D-MAN wrote: {edit} I'm going to do the back-to-back thing when I get home, and I'll post the results. ---------------- And... did you find anything? Rob Quote Link to comment Share on other sites More sharing options...
D-MAN Posted August 23, 2005 Author Share Posted August 23, 2005 Rob, yes, I tried it. They are round magnets and repelled on the edges if off center and attracted at the center (vented pole-to-pole) which confused me. I expected it to be clearly one way or the other and it is not. DM Quote Link to comment Share on other sites More sharing options...
formica Posted August 23, 2005 Share Posted August 23, 2005 I'd simply try connecting a AA battery to see if the cone moves outward when you apply a positive signal to the positive terminal... no grey zone with that test... Quote Link to comment Share on other sites More sharing options...
D-MAN Posted August 23, 2005 Author Share Posted August 23, 2005 Sounds like a plan. The results should be unavoidable. DM Quote Link to comment Share on other sites More sharing options...
D-MAN Posted August 23, 2005 Author Share Posted August 23, 2005 Guys - this is making me nervous! I swapped back to a pair of drivers that previously displayed phase problems, and of course, based on previous experience, I connected them with one being out-of-phase. Guess what! out-of-phase. So reconnected CORRECTLY and everything is fine. Now, I know what you're thinking - I originally screwed up on the wiring - NOT. I CAN ASSURE you that I did NOT make a mistake. I was scrupulously attentive. And I swapped them in and out more than once with the same exact results. I am now thinking that they sound out-of-phase before they are "broken-in" (yes, they DO relax a bit and become more efficient especially in the low end as time used increases). These have about 2 full weeks on them. Has anyone else experienced this? Is it even possible? If I swap them out with the other "new" pair and this happens, I'm going to do a #2 right then and there. The other "new" pair has about a full day on them, so if my premise is correct, then they should sound out-of-phase, that is, the low frequencies cancel each other out. DM Quote Link to comment Share on other sites More sharing options...
formica Posted August 24, 2005 Share Posted August 24, 2005 ---------------- On 8/23/2005 4:41:55 PM D-MAN wrote: Now, I know what you're thinking - I originally screwed up on the wiring - NOT. I CAN ASSURE you that I did NOT make a mistake. I was scrupulously attentive. And I swapped them in and out more than once with the same exact results. I am now thinking that they sound out-of-phase before they are "broken-in" (yes, they DO relax a bit and become more efficient especially in the low end as time used increases). These have about 2 full weeks on them. ---------------- Are we taking bets?? Drivers do break in, but their T/S parameters settle in within a short period (less than an hour if i recall). OTOH, "sounding" out-of-phase isn't necessarily actually out-of-phase... perhaps your testing was a little unscientific? Rob Quote Link to comment Share on other sites More sharing options...
D-MAN Posted August 24, 2005 Author Share Posted August 24, 2005 No, 3 different pairs of new drivers with the same results is enough for me. Wiring is not an issue, don't you think that I checked it, and that more than once, just to be sure?! That's the FIRST thing I checked! What I can't figure is why it would change. But it does - so I posted it for others, even though I know that it will sully my reputation. But: I am not making this up, and I made no polarity mistakes! I have a new pair of drivers coming in next month...I'll place a bet, I got a sure thing! Same thing is going to happen, and you can take that to the bank. I just don't know WHY it is happening. P.S., there appears to be quite a long break-in for them to "loosen up". Indeed, I am not scientifically testing anything, just listening VERY intently, as this is rather expensive. DM Quote Link to comment Share on other sites More sharing options...
formica Posted August 25, 2005 Share Posted August 25, 2005 ---------------- On 8/24/2005 12:28:51 PM D-MAN wrote: What I can't figure is why it would change. But it does - so I posted it for others, even though I know that it will sully my reputation. But: I am not making this up, and I made no polarity mistakes!... P.S., there appears to be quite a long break-in for them to "loosen up". Indeed, I am not scientifically testing anything, just listening VERY intently, as this is rather expensive. ---------------- What i was trying to say was perhaps your listening tests showed that there was some sort of deficiency with your new drivers, but they may not have actually been "out-of-phase". Rob Quote Link to comment Share on other sites More sharing options...
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