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You know when you pull the headphone plug out halfway and the sound becomes kind of mono?

post #1 of 7
10/1/11 at 8:47pm
Thread Starter 

Is that actually a perfectly even signal to both earcups or is that lopsided to the right?  I don't care if it's the sum of both channels or if it's dropping one of them, but is it sending the same voltage and presenting the same resistance on each line?  Or is it different voltage and/or different resistance (thus potentially response)?

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post #2 of 7
10/5/11 at 1:42pm
Thread Starter 

No one?

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post #3 of 7
10/5/11 at 2:06pm
Quote:
Originally Posted by Reticuli2 View Post

No one?


I'm not this No One person you're looking for, but I'll answer anyway. biggrin.gif

 

That's what happens when the jack's contact for the right channel (ring on the TRS plug) bridges the little bit of plastic between the tip and ring contacts on the plug and contacts them both.

 

You're getting the sound for the right channel equally in both headphone drivers. The amplifier will continue to output the same voltage, but it sees the two headphone drivers in parallel, so instead of that amplifier channel seeing say, a 300 ohm load, it sees a 150 ohm load which draws twice the amount of current from that channel and the channel will dissipate four times the power.

 

se

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post #4 of 7
10/5/11 at 9:19pm
Thread Starter 

So then, that would mean this "method" could be used to check where the headphone's mono center image & channel balance would be, correct, independent of the amp/jack's own channel imbalances?

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post #5 of 7
10/5/11 at 9:59pm
Quote:
Originally Posted by Reticuli2 View Post

So then, that would mean this "method" could be used to check where the headphone's mono center image & channel balance would be, correct, independent of the amp/jack's own channel imbalances?



Interesting idea! I would suppose that it would work. In theory, of course. I've never tried doing it that way. 

 

There might be a slight difference because one part of the TRS plug will have a more secure connection than the other, but I don't think that would be significant or noticeable at the amperages we are talking about here. 

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post #6 of 7
10/5/11 at 10:20pm

 

What Chromako said.

 

se

 

 

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post #7 of 7
10/5/11 at 10:44pm
Thread Starter 

I've been doing that for over a decade for testing headphones postions (and IEM insertion) quickly, but the night I posted that I realized I could be wrong and it might actually be slightly imbalanced to the right, such as for reasons of impedance differences if the right contact is slightly weaker than the left in the jack.

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