I now have HD650s with 1 old and 1 new driver

So the left driver on my 4-5 yr old HD650s died, and to my bemusement they came back from Senn's UK repair centre with a new type driver in the left can. This is despite me raising my concern that they would sound unbalanced. (Which may of course mean that my concern was unfounded)

Anyhow, right now I find the sound odd. I am delaying more in depth judgement for at least another week.

I would appreciate any input and anecdotes relating to similar experiences any of you guys have had. Also any comments on the burn-in and Old vs New HD650 debates would be cool. I am guessing if you believe in either of those phenomenons the only natural conclusion would be that my drivers are now missmatched?...

Thanks

Oh, and by the way: AAAAAAAAAAAAAAAAAAAARRRRRRRRGGHHHHHHHHH

Thanks for the reply, I am starting to really wish I had done that.

For all their quirks I really loved the sound of my 'phones the way they were. Is it likely that a person who loved the HD650s for their warmth and musicality could find newer HD650s a bit cold and clinical sounding, or do they more or less sound the same? (or better all round)

Sometimes people find it hard to move on from what they know, right?... This is scary for me because these are the only high end headphones I have ever owned. So while my head is being logical and reminding me that there are loads of other headphones I may get on with even better, my heart is saying "noo! I will never love a pair of headphones as much as I loved those Senn's" (A bit like getting dumped really, but more traumatic lol)

But from what you have said it appears the new Senns retain or improve upon everything I like about my old phones, so hopefully the transition will be painless. The reason I thought that the new ones may sound a little clinical is that I always assumed that the veil was a symptom of the warmth and laid back presentation of the old model.

I now feel able to comment on the strange sound of these 'phones. It is all in the imaging. I cant help the feeling that I am hearing two of everything. Everything sounds fragmented, some notes (mainly treble) dont sound "clean". The sounds feel more "hollow" compared to before where everything had a lovely weight to it, like solid objects I could visualise just in front of my eyes.

Another interesting thing comes up when I switch on/off the crossfeed on my amp. Before, during most songs, it was easy to distiguish exactly what happened when it was put on (image moves towards centre more, bass weight increases slightly and sound becomes warmer). Now switching it on just creates another kind of muddle (e.g the sound changes but it is very hard to work out exactly how)

I see what you mean... If I were to come to a conclusion from that thread it would have to be that the new ones are bassier but more bass lean; have more treble, but less treble; are darker and brighter and less veiled (but with more veil)

I guess this is a descision I will have to make on my own.

The thing that worries me is that if I send it back to sennheiser and ask for two new drivers (basically a "new" HD650) I may end up with a headphone that I like less, although probably more than what I have at the moment. One other slight issue is that I wonder if they have the same capacity at their repair centre to match two drivers as they do at their factory (if that makes sense). All the time just buying a new pair is looking more and more attractive (although £200 + isnt) 

It annoys me that on this forum there are hundreds of threads like this that get politely bumped, until suffering eventual death a couple of days down the line, but if someone posts a thread like "The bass on headphones sucks!!" it gets 300 replies in one day.

Also, do Sennheiser not have a representative on this board? I can't help feeling they should have.

Anyhow, thanks for the replies Kingtz :)

Thanks for the replies :) 

Do you know who it was that ended up in the situation I am in? I would love to talk to them

I dont really understand this whole driver matching thing... but I'm guessing that it is the most likely cause of what I am hearing right now. Would anybody be able to explain to me how two drivers can either "work" or "not work" together, and what the practical implications are for me right now. 

I am currently bidding on an old pair of HD650s on Ebay, so if I will tell you how that one goes.

Thanks

The bass on headphones SUCKS!!!!!!!111111