[Ikarios]

Since headphone drivers have polarity, how noticeable would it be if during a recable, a builder flipped the signal and ground wires? Would it affect volume, presentation, etc? Would it just sound really "wonky" or would it be obvious that something was very very wrong? TIA!

 

[Avro_Arrow]

While I have not experimented with this myself and I'm sure someone will disagree...
I think you would be hard pressed to tell if one driver was in phase or out of phase
with the other. In the world of speakers, where one signal can interact with the
other "in the air", it would be really obvious. In the world of headphones, the signal
from one channel can not interact with the other (only inside your head...).
On the other hand, try a recording of one frequency in one ear and a different in the
other ear and notice the beat frequency generated inside your head...

 

[Ikarios]

So flipping ground/signal on one driver doesn't actually affect the sound, but rather affects the phase? Interesting. Both sides sound the same to me but the presentation is extremely peculiar for this pair of headphones - it's like the imaging is very "segmented" - guitars, vocals, cymbals all sound like they're coming from totally different locations. It's very strange and I haven't heard this kind of presentation in a headphone before, but I'm not sure if it's the headphones themselves or something that went wrong in recabling.

 

[digger945]

Quote:

So flipping ground/signal on one driver doesn't actually affect the sound, but rather affects the phase? 

Referring to both headphones and speakers, perhaps to some it may not make any difference to the sound presentation, but for me not only is it immediately noticeable, but unlistenable until corrected.
 
Try it and see(hear.)
 
 

 

[Avro_Arrow]

Here is an interesting article on the subject.

 

[nikongod]

 
Quote:

While I have not experimented with this myself and I'm sure someone will disagree...
I think you would be hard pressed to tell if one driver was in phase or out of phase
with the other. In the world of speakers, where one signal can interact with the
other "in the air", it would be really obvious.

To agree with digger945: IME doing this is BAD BAD BAD. Its very noticeable with headphones. It does not result in the same cancellation effect as with speakers, but still bad. (Negative * positive = negative = bad)
 
The effect of flipping phase in 1 channel is used as a sound effect in some music. If it happens with good quality Jazz or Orchestral music your headphones are wired wrong.
 
Wiring both drivers backwards (double negative = positive) is harmless. some people claim to be able to hear this, but Im suspicious at best. AKG does this on purpose to solve some funky thing with headphones causing feedback loops with microphones. 

 

[Avro_Arrow]

I quite agree with you. I did mention I had never been exposed to headphones that had been wired wrong and after
reading the article I will try it and see for myself how it changes the sound.
 
Quote:

 

To agree with digger945: IME doing this is BAD BAD BAD. Its very noticeable with headphones. It does not result in the same cancellation effect as with speakers, but still bad. (Negative * positive = negative = bad)
 
The effect of flipping phase in 1 channel is used as a sound effect in some music. If it happens with good quality Jazz or Orchestral music your headphones are wired wrong.
 
Wiring both drivers backwards (double negative = positive) is harmless. some people claim to be able to hear this, but Im suspicious at best. AKG does this on purpose to solve some funky thing with headphones causing feedback loops with microphones. 

 

 

[misformatt]

This may seem like a silly question, but how would you discern which contact/solder point on a driver is which?  I have some drivers that have been disconnected from their original cables, and I'm at a bit of a loss as to where to solder the respective wires.

 

[nikongod]

 
Quote:

This may seem like a silly question, but how would you discern which contact/solder point on a driver is which?  I have some drivers that have been disconnected from their original cables, and I'm at a bit of a loss as to where to solder the respective wires.

They are GENERALLY the same on both drivers. Look at them from the back. The left is + (or minus, but just do the same) and the right is - (or the opposite...)
 
If you REALLY care (as long as they are both the same it doesn't really matter) you can buy a little test device that tells you when you play a special CD or hook up some other special gizmo which is included with the thing. Look for "polarity checkers" at pro-sound shops. They usually sell for like $100, and it may be possible to DIY one but I haven't investigated much.
 
As a last ditch effort, if you have "known good" headphones to listen to, you can hear it if you do it wrong. Flip one, and your back in business. 
 
I should note now, that they are occasionally flipped. I have a set of beyers that are wired backwards on 1 driver (left is + on 1, right is + on the other). Dunno why it happened that way, but 1 headphone in the 30 or so I have cracked doesn't really phase me.

 

[misformatt]

Quote:

 

They are GENERALLY the same on both drivers. Look at them from the back. The left is + (or minus, but just do the same) and the right is - (or the opposite...)
 
If you REALLY care (as long as they are both the same it doesn't really matter) you can buy a little test device that tells you when you play a special CD or hook up some other special gizmo which is included with the thing. Look for "polarity checkers" at pro-sound shops. They usually sell for like $100, and it may be possible to DIY one but I haven't investigated much.
 
As a last ditch effort, if you have "known good" headphones to listen to, you can hear it if you do it wrong. Flip one, and your back in business. 
 
I should note now, that they are occasionally flipped. I have a set of beyers that are wired backwards on 1 driver (left is + on 1, right is + on the other). Dunno why it happened that way, but 1 headphone in the 30 or so I have cracked doesn't really phase me.

Thanks for the help.  I can't pick out any markings on the back of my HFI-780 drivers, though one solder point is green and the other is copper. 
 

 

 

[samsquanch]

here is a free way to check this.  Download Audacity, create a 100 Hz sine wave in the wave editor section, play the tone with your headphones off, but with both drivers held close and directed towards one of your ears, then invert the sine wave for one of the channels, then play through your headphones again.  If it sounds quieter without a channel inverted, then one channel is wired out of phase, if it sounds quieter with one channel inverted, then your headphones are fine.