A kind of noobish question about headphone wire polarity

[bladeweaver]

I was taking apart my HD 555's to check them out for re-cabling today, and I found that (obviously) each driver had going to it 2 wires. Now, one of them has to act as the positive and one has to act as the negative, but how does that work? If someone could give me an explanation of the polarity of headphone cables, and how the whole ground/left/right thing fits in in terms of positive and negative charge, I would be very happy. Like are the channels positive and the ground negative? Or vice versa?
Thanks for helping a poor nooby out.

 

[ericj]

Well, the transducer consists of an axially polarized magnet and a coil attached to a diaphragm, right?

Positive voltage will move the voice coil along the axis of the magnet in one direction and negative in the other direction.

If you have an old speaker that you never plan to listen to again, and a battery, you can observe that behavior yourself. Don't do it to anything you weren't planning to throw away, though. DC is bad for voice coils.

I have to admit that i once used a half dead CR2032 3v lithium cell to hold a 5" speaker cone in place for about an hour while the glue between the cone and the foam surround cured.

This was from an old Boston bookshelf speaker and the foam surround had literally neatly detached from the cone all the way around it's circumference, but was still 99.9% intact.

Lacking any better ideas of how to apply even pressure between cone and surround for an hour, and knowing that the speaker was a throwaway if i didn't find a way to do that, and not worth much in the first place, I figured it was worth the gamble.

Worked. Sounds fine. I only use those speakers as rear surrounds anyway. Don't try this at home, trained professionals on a closed track, results not typical, etc.


AAAAnyway . . . .


Audio signals are AC, modulated positive and negative voltage. If you hook up the transducer backwards, the diaphragm will be moving out when it should be moving in, and vice-versa.

It'll still make sound, but it'll sound a little funny.

How do you tell what the polarity is? You hope that somebody marked it, that's how. I have some old Braun speakers where someone literally marked one side of the magnet with an X in red sharpie. Generally + is for signal, - is for ground. If there is only one mark, hand made, it's probably "signal here" even if it's a dash. You hope.

In headphones, two of those four wires will be connected to the same conductor on the plug - those are ground. As for the transducer end, best of luck to ya if they're already detached.

 

[Garbz]

actually things sound the same regardless of polarity. It's when the left tranducer is in the opposite poarity to the right on that things sound like you are on drugs.

 

[Jeff Wong]

Quote:

Originally Posted by Garbz actually things sound the same regardless of polarity.

I would disagree - Inverting polarity will affect compression and rarefaction as ericj noted. This is audible, especially in instruments like bass. Many Ryko and Impulse CDs are mastered with inverted polarity for some strange reason, and you can hear the difference when switching from 0 to 180 degrees. You might find the following interesting reading:

http://www.positive-feedback.com/Iss...woodeffect.htm

 

[DaKi][er]

Quote:

Originally Posted by Jeff Wong I would disagree - Inverting polarity will affect compression and rarefaction as ericj noted. This is audible, especially in instruments like bass. Many Ryko and Impulse CDs are mastered with inverted polarity for some strange reason, and you can hear the difference when switching from 0 to 180 degrees. You might find the following interesting reading: http://www.positive-feedback.com/Iss...woodeffect.htm

On my newly finished DAC I put in independent switches that invert the polarity of the channels and I have yet to be able to hear any difference if they are both inverted or not, yet invert one and it completely stuffs the sound up

Though I could see it having an effect on a certain few recordings, just nothing i have tried

 

[DaKi][er]

On second listen, I do think I can hear something different in the bass

I'll have to look into this a bit more....

 

[robzy]

My understanding is that reversing polarity makes no difference what so ever.... but i have no knowledge what so ever to back that up with. Sorry.

Rob.

 

[DaKi][er]

Quote:

Originally Posted by robzy My understanding is that reversing polarity makes no difference what so ever.... but i have no knowledge what so ever to back that up with. Sorry. Rob.

When you come to the meet that is coming up, I'll have to let you decide for yourself

 

[bladeweaver]

thanks for the help guys =)