Mechanical ringing in right side of Ultrasone Pro 550

[Chunk3rs]

I'm wondering if anyone can help me diagnose this problem or if anyone has experience with this. I've searched to forums and can't find anything.
 
I have a pair of Ultrasone Pro 550 that produce a ringing sound anytime there is a transient (eg the volume 'tic' on an apple) or if they are physically bumped. The ringing is at about 875Hz and has made using these almost impossible. I've recorded the sound using a contact mic and by tapping the outer shell of the headphones lightly:
 
soundcloud.com/todd-beene/ultrasone-pro-550-headphones
 
Any ideas?

 

[davidsh]

Doubt you'll be able to fix it. If out of warrenty you could open it up and have a look just to see if there's an obvious reason for the problem you encounter.

 

[midihendrix]

Hi, I have the same exact problem in my Pro 750. I have never been able to resolve it. Please let me know if you figure anything out.

 

[Chunk3rs]

I haven't come up with anything yet, but I'll let you know if I do!

 

[Chunk3rs]

I've sent an email to the contact email listed on the Ultrasone website. I've also sent a message via the online contact form. We'll see ...

 

[Chunk3rs]

I haven't heard anything from Ultrasone, so I figured I'd open them up again and take a look. I mean, they're already unusable so what the heck.
 
I took it apart in stages and kept verifying that the ringing was still occurring. I had the inner plate with the driver attached in my hand and it was still making the noise when tapped. I even muffled the plate with my hand to see if that was the cause, but that only made the ringing even clearer. So I deducted that it had to be the driver itself, which is a major bummer. I took out the screws to remove the driver and try it by itself, but then I decided I didn't want to cut away the glue sealing it to the plate. So I put the 3 screws holding the driver on and tightened them right up until before they strip (heh heh). I re-attached the plate to the housing, re-attached the pads, checked for ringing, and lo and behold, the ringing had stopped. I think tightening down the screws on the driver may have done it. Anyway, as of right now, there is no ringing and I am elated. 

 

[Chunk3rs]

Wouldn't you know it, I received an email from Ultrasone today. I actually think their diagnosis of the problem is correct, I must have inadvertently muffled the diodes myself:
 
Here's what they said:
 
"Thank you very much for your mail.
 
First: Happy New Year !
 
Thanks for the recording. We think the ringing may be caused by the overload-protection-diodes. They are soldered on the speaker, maybe the wires are too long, so that they react like a “tuning fork”.
But that`s not a problem – the service center in your country could repair/fix it.
 
So where are you come from (which country)? USA ?
 
I am looking forward to your reply – later I will come back with contact details of the service center in your own country."
 
There ya go!

 

[midihendrix]

Thanks, that's great to hear! I will attempt to fix mine also.

 

[midihendrix]

And thanks again for your replies.