[Tompie913]

I ordered an AKG K550 MkII a couple of weeks ago, and I loved it. However, one of the earcups clicked a bit when adjusted, which I found annoying in an otherwise perfect headphone. So I got an RMA from Amazon and decided to order a second pair in the meantime to use before I sent back the first pair. Then I tried it out and was amazed to find that the sound signature sounded a fair bit different. The first thing I noticed was that the new pair seemed a little bit quieter. Then after further listening I concluded that they had less soundstage and more bass. Overall, the new pair sound warmer to me, with noticeably more bass and less soundstage. So now I can't bring myself to send back the first pair, and I think I might just send back the second pair and live with the very minor quibble of occasional clicking from the earcup assembly.
 
I tried to figure out why they sound different. The first thing I noticed different when I opened the new ones is the earpads seemed a little bit more fully stuffed, so I swapped the earpads. That seems to have made a tiny bit of difference but they still sound different to me. Then I thought it must be burn in, but I think I have both pairs close in terms of usage time by now.
 
I've actually noticed this before with a super cheap pair of Griffin Woodtones. I ordered them in a Sapele wood finish, but then they broke and I got a warranty replacement in Walnut. The Walnut ones sounded considerably crisper to me, but I put that down to the different type of wood used. So basically, is this a thing, or is it all in my head?

 

[serman005]

  I ordered an AKG K550 MkII a couple of weeks ago, and I loved it. However, one of the earcups clicked a bit when adjusted, which I found annoying in an otherwise perfect headphone. So I got an RMA from Amazon and decided to order a second pair in the meantime to use before I sent back the first pair. Then I tried it out and was amazed to find that the sound signature sounded a fair bit different. The first thing I noticed was that the new pair seemed a little bit quieter. Then after further listening I concluded that they had less soundstage and more bass. Overall, the new pair sound warmer to me, with noticeably more bass and less soundstage. So now I can't bring myself to send back the first pair, and I think I might just send back the second pair and live with the very minor quibble of occasional clicking from the earcup assembly.
 
I tried to figure out why they sound different. The first thing I noticed different when I opened the new ones is the earpads seemed a little bit more fully stuffed, so I swapped the earpads. That seems to have made a tiny bit of difference but they still sound different to me. Then I thought it must be burn in, but I think I have both pairs close in terms of usage time by now.
 
I've actually noticed this before with a super cheap pair of Griffin Woodtones. I ordered them in a Sapele wood finish, but then they broke and I got a warranty replacement in Walnut. The Walnut ones sounded considerably crisper to me, but I put that down to the different type of wood used. So basically, is this a thing, or is it all in my head?

If they are both 550 Mk II's, they should sound very, very similar. They should not sound like two completely different headphones. My only thought is that one of the pairs is somehow defective (the second?). Nothing else makes sense to me, based on what you are hearing. I'd keep the first pair as well. FWIW.   ---)