[Lumos]

We Know that Sennheiser HD518/558/598 uses same driver. However I discovered slight differences, see the attached photos:
 
I don't know if sound characteristic has been changed. anyway it is interesting information... if anyone can illuminate this issue I would be happy. Now I am using old left and new right driver, but they pair each other very well.
 
HD558 driver purchased from Amazon.com manufacture date 05.11.2010 driver's part number: 93481B

 
New HD598 driver purchased from ebay.de manufacture date 16.02.2012 part number: 528480

 
I tore down damaged left driver also


 
cheers !!!
 
Lumos

 

[streetdragon]

How is the sound? did you detect any differences in them?

 

[Mad Max]

He said that they pair well, so probably not.
 
The printed number on the diaphragm is probably a batch number or something like that.

 

[Lumos]

streetdragon No significant change, I was thinking that new drivers are more deep in space but it could be my imagination!!! report back after some time but again they pair each other very well.

 

[kimvictor]

Interesting. It's not really much of a surprise though. Shure did the same for SRH840 and SRH940. Same driver, just different damping and materials. 940 is much better than 840 though. At least a class above. I think it's the same for Senn. 598 is a class above 558 imo, despite having almost identical drivers.

 

[joshwalnut]

Is it just me or do they look the same? I don't see any differences besides one is dirty and one is clean. Also, the photoes are at different angles and one has a flash right on it.... bad comparison is bad! lol j/k... well not really.
 
I still believe that both headphones are the same, just that one looks like an inside of a car and is supposedly more comfortable. All for $100 extra?? pffffffffff you can keep it sennheiser 

 

[streetdragon]

Quote:

Is it just me or do they look the same? I don't see any differences besides one is dirty and one is clean. Also, the photoes are at different angles and one has a flash right on it.... bad comparison is bad! lol j/k... well not really.
 
I still believe that both headphones are the same, just that one looks like an inside of a car and is supposedly more comfortable. All for $100 extra?? pffffffffff you can keep it sennheiser 

lol but the HD598 does sound more refine even after the HD558's extensive modding. Though the difference is slight, and it is more of just different than better. That was my old configuration though. I would like to try the comparison again with my new mods.

 

[joshwalnut]

Quote:

lol but the HD598 does sound more refine even after the HD558's extensive modding. Though the difference is slight, and it is more of just different than better. That was my old configuration though. I would like to try the comparison again with my new mods.

 
$10 cheese always tastes better then $5 cheese!  
 
You could be right though, i've never tried the 598's. Maybe the drivers from the 598's series are blessed by the sorcerers from audiophile university.... hence why everyone claims they sound better... THIS EXPLAINS EVERYTHING!!!!
 
If you did compare them (stock 598 and HEAVILY modded 558's)... it wouldn't be fair. You would have to mod the 598's at least HALF of what mods the 558 has got on it.... lmao

 

[kimvictor]

Even with same drivers, things like damping, soldering, cable, and driver placement changes a way headphones sound.

 

[streetdragon]

^ yeap, damping is the only difference between the T50rp and the Thunderpants.

 

[joshwalnut]

I have no idea what damping means and i'm too lazy to google it.... explain to me like i'm 5.... anyone? 

 

[streetdragon]

Quote:

I have no idea what damping means and i'm too lazy to google it.... explain to me like i'm 5.... anyone? 

in a nutshell: manipulating material placed in earcups to absorb/reflect/manipulate sound pressure waves 

 

[Lumos]

Update:
 
received brand new left driver from Sennheiser (from Germany) pictures here:
Different part numbers could be due to manufacturing for EU market and for USA market, (NOT SURE) NO sound-wise difference at all. ) Happy listening to which version you have

 

[Headzone]

Same drivers..? What makes the gap in sound quality difference then? Just worse quality/resonating plastic around the driver in the cheaper models?

 

[Lumos]

Yes the only difference is the grill

you can mod 518 like 598, inner cups are same also, you need to cut the plastic grill and install metal one like 598.