[bassophile]

I'm not suspecting I've been sold outright fakes because the sound quality is still actually good in itself, but I used to own a pair of HD650, and the pair I've bought (2nd hand) now are much brighter - I think on the bright side of neutral. The bass is less, the treble is more and the midrange is more forward. They are not much darker than my SR60!!
 
I don't think I believe in 'old' and 'new' versions of the HD650 - and both my present pair and my older pair of HD650 were the silver backed types anyway but I'm sure there is still a marked difference in sound signature.
 
This leads me to conclude that there must be HD600 drivers in th HD650 as HD600 are known precisely for being like the HD650 yet with more forward midrange, increased treble and reduced bass - which perfectly describes my present HD650. The HD600 and HD650 drivers are the same size and shape so fitting them in could go relatively undetected.
 
So, how common is the practice of re-selling HD650 fitted with HD600 drivers - and how do you confirm it if you suspect you have bought one of these pairs?

 

[Uncle Erik]

There was a lengthy thread here about how Sennheiser revised the HD-650 so it isn't as dark as it used to be. I'd recommend reading through it and weighing the evidence.

I'm not sure why someone would replace HD-650 drivers with HD-600 ones. Don't they cost about the same from Sennheiser?

Also, what are you driving these with? The HD-650 changes character depending on what you plug it into. If you've changed amps since you last heard the HD-650, it could very well be showing you the character of your new amp.

 

[dcpoor]

sennheiser charges more for hd600 drivers last time i checked. selling hd650's with hd600 drivers as means of a scam makes no sense.

 

[olor1n]

I agree with the highly adaptive nature of the HD650 based on what they're plugged into, but I never understood criticisms of an overly laid back and boring headphone. Mine were purchased new in December, and while they are certainly smooth and impart low listener fatigue, they can also be very aggressive (if present in the recording). Although more refined, with more body and extension in the low end, I find them to be just as forward and energetic as my MS-1i. Great cans for sizzling distorted guitars with crunch, dispelling another myth that they aren't suited for rock.

 

[Uncle Erik]

It all depends on what you plug the HD-650 into. I found them fast and tight on the Zana Deux; very enjoyable. But that's more a characteristic of the Zana that the HD-650 shows off.