Speakers wired correctly, but play out of phase

[chadbang]

I have a pair of Dahlquist speakers. When I wire them correctly to the amp (positive amp terminal to positive speaker terminal; negative amp terminal to negative speaker terminal) they play out of phase? I determined this using my Stereophile test CD. When I change the wire arrangement on ONE speaker (positive amp terminal to negative speaker terminal; negative amp terminal to positive speaker terminal) the speakers are now in phase. How could this happen? I think someone refoamed the woofers. Would mixing up the woofer wires (they're not color coded) do this to a speaker?

 

[krmathis]

Yeah, mixing up the woofer wires may indeed get it out of phase. The tweeter may be in phase, but masked by the much bigger woofer.
So I suggest you open up and fix it. Making sure all transducers are playing in the same phase.

 

[chadbang]

Damn, I opened it up and the woofers appear correctly wired. So now I'm stumped. It's such a pain opening up my Dahlquist DQ10s (lots of screws and chicken wire). Only now did I just think about a FACTORY mistake. I wonder if they could have goofed up the crossover/woofer connections? Arrrrggghhh! I guess I need to take them apart again and trace the leads. What a pain. Is there any disadvantage to me leaving them wired "wrong" to keep them in phase?

 

[Headdie]

If the speakers are completely out of phase (tweeter and woofer), then connect one of them in reverse. Now, if you have a second pair of speakers, you should make sure the problem is not the amplifier's output. This way, you won't mess up in your speakers when the problem is in the amplifier.

 

[Headdie]

By the way, the problem could be anywhere along the chain. It could simply be your CD player that is plugged out of phase...

 

[mrarroyo]

I sure hope you get it fixed, the DQ10 are among the best speakers I have ever listened to. Good luck.

 

[sahwnfras]

Quote:

Originally Posted by Headdie /img/forum/go_quote.gif By the way, the problem could be anywhere along the chain. It could simply be your CD player that is plugged out of phase...

...what, like a bad interconnect? Iv never heard of a CD player being out of phase, or in phase or anything like that.

 

[SiBurning]

Even the data on a CD or vinyl can be recorded out of phase. If it's 180 degrees out, maybe you have one of those legendary components that was built on a Friday afternoon when someone connected a pair of wires somewhere backward.

 

[mulveling]

Most tube preamp circuits are phase-inverting by design. If you don't have such a preamp, it could still be any number of things as mentioned above.

 

[chadbang]

Quote:

Originally Posted by SiBurning /img/forum/go_quote.gif Even the data on a CD or vinyl can be recorded out of phase. If it's 180 degrees out, maybe you have one of those legendary components that was built on a Friday afternoon when someone connected a pair of wires somewhere backward.

I'm wondering about this. Going to open them up and do some testing.

 

[sahwnfras]

Quote:

Originally Posted by chadbang /img/forum/go_quote.gif I'm wondering about this. Going to open them up and do some testing.

Before you do something like that. Why not just try a diff CD player on the system. As I said I have never heard of a CD player having this kind of problem, and if so how do you plan on finding this fault.

If someone brought in a CD player to my work saying that the CD player was out of phase i would think their crazy. I would test it out, but most likely it would work just fine.

 

[9pintube]

STUPID QUESTION MAYBE, but have you tried the old battery trick???? Just hold a wire from the positive post of your speaker to the pos. side of a Battery and do the same for the Neg. side....... This should cause your driver to move out, not suck in....Do the same on your other speaker......If they are both moving in the same direction (outwardly) while touching the battery as mentioned above they're in phase if not try to perform this test on the drivers before they enter their crossover....on each speaker..good luck.....

 

[Pricklely Peete]

Here's a useful page that may help answer some of your questions Dahlquist

Peete.

 

[SiBurning]

Since the speaker was refoamed, that's obviously the place to look carefully. I'd also compare the crossovers. Maybe one of the channels blew and this was a repair with a different crossover or a different woofer or who knows what they may have done. Just using a different value capacitor is enough to affect the phase, and you can get a different value if the capacitor is stressed or aged compare to the other. Same with resistance.

I've read about components being built with a channel out of phase. It's obviously very rare because most people never notice. How many people hook up a test disc? It's pretty rare anyway. Might be more common in stuff manufactured in the 1970s and earlier when things were still hand wired and soldered. It was common to have all kinds of problems from unpolarized power plugs, and phase seems like a potential problem, although both channels would be affected equally by this. Anyway, this is kind of besides the point. Just curious, and like to hear about stupid stuff like this.

Thinking some more... was the cone refoamed? That could affect its mechanical resistance. If it was more than the foam... what would happen if the cylinder on one were inserted backward? I don't think the direction of the wiring on the cylinder would change the direction of movement, but maybe I have that wrong. (Assuming it's that kind of cylinder.)