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Anyway to check if my dt990 600ohm is broken?

post #1 of 13
8/21/11 at 4:08pm
Thread Starter 

I just put on my dt990s and started listening to music and I realized that the drivers aren't balanced any more.  The right one is about 30% more powerful than the left.  It seems like the highs are affected more. I plugged in my dt880's and those played fine, so its not my source or amp.  Any ideas on what just happened?

 

I hope its just a cable issue, not a driver issue.

 

Oh for what its worth, I got these used from a head-fier a couple months ago and they were bought new in april 2011. 

 

Any tips/tests would be appreciated :)

 

thanks guys!


Edited by rontruong - 8/21/11 at 5:37pm
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Gear mentioned in this thread:

beyerdynamic DT 990 Pro Headphones
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post #2 of 13
8/21/11 at 4:35pm
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Move the cable around. While playing music, get one inch seconds at a time and turn the cable 360 degrees

 

I know my receiver has a balance problem around 5%, but nothing at 50%.

 

Either you have a broken connection somewhere in you cable or your audio is faulty.

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post #3 of 13
8/21/11 at 5:00pm
Thread Starter 

Yup I already suspected the wire and started bending and twisting it random directions and tried two different source connections.  Nothing changed :(.  Oh well I'll look in to warranty thanks for the effort! :D

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post #4 of 13
8/21/11 at 6:10pm

If you have a multimeter you can check if they still read at 600Ohms. It could be a dodgy solder joint, and if it's that then I can easily repair it for you.

 

Also what amp are you using? If it's a tube amp they can sometimes become unbalanced if a driver tube is dying. 

 

Are you using the PC as a source? If so check the balance controls on your PC to make sure they are set correctly.

 

 

Lastly if it's the driver and beyer won't repair it, I can repair it for you for just the price of the driver. Driver's are $66 I believe and all you'd have to do is send the phones to me, I order the driver, repair your phones and then ship them back.

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post #5 of 13
8/21/11 at 6:24pm
Thread Starter 

thanks zombie_x.

 

with respect to this picture. http://en.wikipedia.org/wiki/File:Jack_plug.png

From 1-2 - 596 ohms

from 1-3 - 10.9 ohms

from 2-3 - 606 ohms

 

Shouldn't left to ground and right to ground be the same number?

 

My PC is currently the source.  Tube AMP is darkvoice 336c.  I have a dt880 600 ohm and everything plays perfectly balanced and normal through those.

 

I think the headphones are fairly new, bought them from a head-fier but I think the purchase date is april 2011.  If the warranty doesn't fall through, I'll definitely contact you.

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post #6 of 13
8/21/11 at 7:37pm

Hey,

 

The left and right numbers won't be the exact same, not unless you get the Manufaktur versions will they be the same. It could be a lot of things that's throwing them off. Most likely it's the driver though.

 

You could always just dial down the volume on the side that is louder so that the sound is even again.
 

Quote:
Originally Posted by rontruong View Post

thanks zombie_x.

 

with respect to this picture. http://en.wikipedia.org/wiki/File:Jack_plug.png

From 1-2 - 596 ohms

from 1-3 - 10.9 ohms

from 2-3 - 606 ohms

 

Shouldn't left to ground and right to ground be the same number?

 

My PC is currently the source.  Tube AMP is darkvoice 336c.  I have a dt880 600 ohm and everything plays perfectly balanced and normal through those.

 

I think the headphones are fairly new, bought them from a head-fier but I think the purchase date is april 2011.  If the warranty doesn't fall through, I'll definitely contact you.

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post #7 of 13
8/21/11 at 9:22pm
Thread Starter 

Oh, just to clarify.... according to the diagram and this picture also

http://img.photobucket.com/albums/v335/RnBdiy/sysplit21.jpg

 

What I meant was:

 

From 1-2 - 596 ohms  Ground (Sleeve) to Right (Middle)

from 1-3 - 10.9 ohms  Ground (Sleeve) to Left (Tip)

from 2-3 - 606 ohms Right( Middle) to Left (Tip)

 

Does this change anything?  If not then...

 

I tried digitally balancing the drivers on foobar but once I balance it, the left driver becomes slightly distorted.  Good to know what my problem is, thanks zombie_x.  I'll be sure to PM you if I need help repairing :).

 

Thanks!


Edited by rontruong - 8/21/11 at 9:27pm
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post #8 of 13
8/21/11 at 9:39pm

Doh! I misread your post, my bad man.

 

Something is wrong there. 1-3 should not register as 10.9 Ohms. It should read as close as possible to 600 Ohms. Measuring 2-3 should give you a value of zero as you would get no signal from joining left and right without the ground. 

 

It should read something like this:

 

From 1-2 600 Ohms (from ground to ring)

From 1-3 600 Ohms (from ground to tip)

From 2-3 0 Ohms (from ring to tip)

 

Has anything at all been done with the headphones? No cable mods at all? If what you're telling me is correct then you have something internally wired wrong.

 

The other alternative is that the jack got messed up somehow and that can be fixed easily with a retermination. It now does not look like a driver issue but a wiring issue. Most likely an internal short in the plug. I can easily and quickly fix this for you in under a weeks time.

 

 

Quote:
Originally Posted by rontruong View Post

Oh, just to clarify.... according to the diagram and this picture also

http://img.photobucket.com/albums/v335/RnBdiy/sysplit21.jpg

 

What I meant was:

 

From 1-2 - 596 ohms  Ground (Sleeve) to Right (Middle)

from 1-3 - 10.9 ohms  Ground (Sleeve) to Left (Tip)

from 2-3 - 606 ohms Right( Middle) to Left (Tip)

 

Does this change anything?  If not then...

 

I tried digitally balancing the drivers on foobar but once I balance it, the left driver becomes slightly distorted.  Good to know what my problem is, thanks zombie_x.  I'll be sure to PM you if I need help repairing :).

 

Thanks!


Edited by Zombie_X - 8/21/11 at 9:40pm
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post #9 of 13
8/21/11 at 9:59pm
Thread Starter 

At first, I thought I was crazy, because I was expecting 600 from L to G and R to G.  So I remeasured a few times w/ my multimeter.... then I was okay I'm not crazy.  Then I put on the 1/4 inch adapter and did it again, haha.

 

What confuses me is that sound still plays on the left, but not as loud of course.  Right still plays fine.  I haven't done anything to the cords, bought em used from someone who got them new in april.  Worked perfectly fine.  Then, I left it in my cabinet for about a month and then I pulled it out today and I heard something completely off.  I hope the drivers didn't get messed up from a weird short somewhere.

 

However, electrically... this makes sense right?  A full 600 isn't shown from L to G, which is the problematic side.  So we aren't able to send 100% the analog signal to the driver.  So that is probably why only a partial sound signature is sent through. 

 

I'm assuming since the L to G still gives out 10 Ohms, a possibility would be that the L to G got shorted w/ the Ground somewhere in the cable before the drivers.  Giving the L to G a shorter path of resistance by skipping the resistance load.  Then since L is connected to G now and doing a L to R measurement, we read the series measurement of the right side 600 ohm... Does this make sense? haha college intro to circuits for the win.......i hope.

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post #10 of 13
8/21/11 at 10:25pm

I'm sure the jack is messed up. It sounds like a short somewhere in the jack.

 

The Ohm rating wouldn't prevent any signal loss, bust a short can make the headphone sound thin, distorted, distant, and even have a lower volume. I am 100% sure it's a short somewhere.

 

My guess is the wires probably are touching in the jack and that's giving you this issue. Do you have anything else to try them on? You just in case I wanna test and see.

 

I am not sure on your last statement about skipping the load. I've never encountered this before.

 

Anyways contact beyer and see what they can do. If they can't help you I sure can.
 

 

 

Quote:
Originally Posted by rontruong View Post

At first, I thought I was crazy, because I was expecting 600 from L to G and R to G.  So I remeasured a few times w/ my multimeter.... then I was okay I'm not crazy.  Then I put on the 1/4 inch adapter and did it again, haha.

 

What confuses me is that sound still plays on the left, but not as loud of course.  Right still plays fine.  I haven't done anything to the cords, bought em used from someone who got them new in april.  Worked perfectly fine.  Then, I left it in my cabinet for about a month and then I pulled it out today and I heard something completely off.  I hope the drivers didn't get messed up from a weird short somewhere.

 

However, electrically... this makes sense right?  A full 600 isn't shown from L to G, which is the problematic side.  So we aren't able to send 100% the analog signal to the driver.  So that is probably why only a partial sound signature is sent through. 

 

I'm assuming since the L to G still gives out 10 Ohms, a possibility would be that the L to G got shorted w/ the Ground somewhere in the cable before the drivers.  Giving the L to G a shorter path of resistance by skipping the resistance load.  Then since L is connected to G now and doing a L to R measurement, we read the series measurement of the right side 600 ohm... Does this make sense? haha college intro to circuits for the win.......i hope.


Edited by Zombie_X - 8/21/11 at 10:26pm
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post #11 of 13
8/21/11 at 10:34pm
Thread Starter 

haha yup, I tested this on my external DAC/AMP, straight from DAC, and my onboard sound card and the results are consistent.  I'm waiting from a response from the original owner about warranty.  Will keep you updated :)  thanks for all the help!

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post #12 of 13
8/21/11 at 10:51pm

No problem man, keep up updated!
 

Quote:
Originally Posted by rontruong View Post

haha yup, I tested this on my external DAC/AMP, straight from DAC, and my onboard sound card and the results are consistent.  I'm waiting from a response from the original owner about warranty.  Will keep you updated :)  thanks for all the help!

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post #13 of 13
11/19/11 at 10:51am

Hello, 

i have exactly the same problem, although my dt-990 are slightly older(like 10 years or so). Recently I noticed that no matter of sound source or cable position one speaker is quieter or maybe even bass-less. As u may imagine this annoys me very much :(

Any ideas :'?

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Gear mentioned in this thread:

beyerdynamic DT 990 Pro Headphones
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