[hade1223]

Hello, I recently cleaned out my DT 990 Pro's drivers because there was a rattling noise which was annoying the hell out of me when it got slightly bassy and I managed to remove some hairs which seemed to be causing the rattling noise. However, now that I have put them back together I have noticed that the bass is actually weaker in the side which I cleaned out. Why may this be?
Thank you very much in advance for any help.

 

[MalVeauX]

Quote:

Hello, I recently cleaned out my DT 990 Pro's drivers because there was a rattling noise which was annoying the hell out of me when it got slightly bassy and I managed to remove some hairs which seemed to be causing the rattling noise. However, now that I have put them back together I have noticed that the bass is actually weaker in the side which I cleaned out. Why may this be?
Thank you very much in advance for any help.

 
Heya,
 
Sounds like you either didn't quite reassemble it completely or maybe you potentially damaged the damping material or stressed a wire or solder point.
 
Very best,

 

[rsxboy]

what do you guys mean by hairs? do you mean the dampening material that the manufacturers put in the headphones?
 

 

[hade1223]

http://www.head-fi.org/t/250313/simple-dt990-mod
On the last picture in the explanations done by that guy you can see the driver under the white plate. I removed the silicone that was attached and took out some of the hairs that were in the drivers. After I did this, I put everything back to how it was supposed to be, and now the bass on the right channel is definitely weaker.
I just tried to reassemble the headphones, however I didn't notice any improvements.
What is damping material by the way?

 

[conquerator2]

Quote:

http://www.head-fi.org/t/250313/simple-dt990-mod
On the last picture in the explanations done by that guy you can see the driver under the white plate. I removed the silicone that was attached and took out some of the hairs that were in the drivers. After I did this, I put everything back to how it was supposed to be, and now the bass on the right channel is definitely weaker.
I just tried to reassemble the headphones, however I didn't notice any improvements.
What is damping material by the way?

 
Damping material can be anything that serves as damping for the driver (coil) when it is moving back and forth,etc...
Usually in form of cottonwool or foam, stored under the driver.

 

[Danmao]

I was going to post something, but I'm pretty sure everyone is already thinking it.

 

[hade1223]

I was going to post something, but I'm pretty sure everyone is already thinking it.

What would that be?

 

[jackwess]

As the guys said, seems like something is damaged. Try re-assembling carefully and check if everything is on place. 

 

[Kodhifi]

Quote:

Hello, I recently cleaned out my DT 990 Pro's drivers because there was a rattling noise which was annoying the hell out of me when it got slightly bassy and I managed to remove some hairs which seemed to be causing the rattling noise. However, now that I have put them back together I have noticed that the bass is actually weaker in the side which I cleaned out. Why may this be?
Thank you very much in advance for any help.

I went through the exact same thing with my 880's. You'd think with the 5mm thick felt pad protecting the driver a hair couldn't make it through, but they do. First off, clean your earpads monthly taking special care to pluck any hairs out. And secondly you likely have the same problem I had. I put them back together and the side I cleaned was weaker than the other, not just lack of bass, but it didn't sound right and wasn't as loud.
 
The issue was that I had unseated the voicecoil. The difference between seated, and unseated, is only a few millimeters, it might 'look' like it's okay but it won't sound like it's okay. Since you've already disassembled them you know how to reach the driver. Gently work the diaphram and it's voice coil at the center back down into the magnetic enclosure. If you make any dents in the membrane, just gently use a little cellophane office tape to pop it back out. Try them on before putting the driver back in and make sure it sounds okay.
 
I nearly had a heart attack when this happened the first time, thought I'd broken them, but the driver went right back in with a little delicate care and they have been working tip top since then.

 

[hade1223]

I went through the exact same thing with my 880's. You'd think with the 5mm thick felt pad protecting the driver a hair couldn't make it through, but they do. First off, clean your earpads monthly taking special care to pluck any hairs out. And secondly you likely have the same problem I had. I put them back together and the side I cleaned was weaker than the other, not just lack of bass, but it didn't sound right and wasn't as loud.

The issue was that I had unseated the voicecoil. The difference between seated, and unseated, is only a few millimeters, it might 'look' like it's okay but it won't sound like it's okay. Since you've already disassembled them you know how to reach the driver. Gently work the diaphram and it's voice coil at the center back down into the magnetic enclosure. If you make any dents in the membrane, just gently use a little cellophane office tape to pop it back out. Try them on before putting the driver back in and make sure it sounds okay.

I nearly had a heart attack when this happened the first time, thought I'd broken them, but the driver went right back in with a little delicate care and they have been working tip top since then.

Before I do it, please could you explain to me what part is the voicecoil? I am not entirely sure what it is I am meant to be doing and I really don't want to further damage the headphones.
By the membrane, are you referring to the really thin layer of plastic which lies over the top of the driver? Because I think that I may have dented or pushed it inwards out of position. Would it be this causing the problem?
Thank you very much for your help. I just want to be very careful before I do anything else, and if it would be at all possible pictures would really help me.