[B-Dawk20]

That is very interesting that one sounded so much different than the other. Maybe one was defective? If you get your new one, I'd try and test their frequency response if you can find someone with the equipment.

 

[Tuneslover]

Was the new HD650 the muddy one? Because my new HD650 definately sounded muddy in the bass when I got them but after burning in for at least 48 hours the sound improved and was no longer muddy. Nvm you bought them both new.

I agree with your comments as my 650's were rather dull sounding, almost boring straight out of the box so I decided to burn them in on continuous play for a week. Opened them up, nice tight bass and very satisfying treble and splendid mids. Further use (I've had them for just over a year now) and they continue to blossom.

 

[mikoss]

I found mine also changed in the first 100 hours. I attributed it to pad wear mostly... I'd have tried swapping pads and checked how they sounded.
Sennheiser has extremely good quality control between components. The 650 drivers are sold in matched pairs, so it's possible the FR was different... Maybe not like "Aww, these see!" though.
The 800's have FR graphs from the factory that can be downloaded by serial number. There are threads with owners posting their graphs... Neurotic audiophile behaviour.

 

[DavidA]

I must be the odd one here, my HD-650 didn't change from day one, they were great from the very first time I put them on.

 

[mysticstryk]

I must be the odd one here, my HD-650 didn't change from day one, they were great from the very first time I put them on.

Same here. I may have percieved a slight change, but I attribute that to my ears and brain getting used to the sound signature.

 

[a44100Hz]

I'm new to these and they're blowing away my other headphones for pure musical pleasure. Taking the black foam disc out from behind the drivers made them even better.

 

[fquails]

  I must be the odd one here, my HD-650 didn't change from day one, they were great from the very first time I put them on.

One of the two pairs I bought sounded fantastic right out of the box.  To be honest, the "muddier" one was pretty good, too.  If I did not have the other one to compare it with, I probably would have never known that one pair was indeed muddier. 
 
FWIW, I offered the Senn tech to "burn in" the muddy phones to see if it will improve.  The Senn tech said "our tests and measurements show that burn in has no effect on the sound quality".   He told me that listening to the phones over time may have a psycho-acoustic effect, where the user gets accustomed to the phones' sound, and the brain adapts to the sound signature.

 

[fquails]

Was the new HD650 the muddy one? Because my new HD650 definately sounded muddy in the bass when I got them but after burning in for at least 48 hours the sound improved and was no longer muddy. Nvm you bought them both new.

I bought both of them brand new, and one of them sounded fantastic right out of the box.

 

[FredrikT92]

Anyone heard the Meier Corda classic FF with HD650? 

 

[pietcux]

Anyone heard the Meier Corda classic FF with HD650? 

I am sure Jan Meier did. I have the Jazz FF and can say that the HD 650 sound superb driven by it. The veil gets lifted without any harshness added. Simply put it is a grat combo.

 

[FredrikT92]

I am sure Jan Meier did. I have the Jazz FF and can say that the HD 650 sound superb driven by it. The veil gets lifted without any harshness added. Simply put it is a grat combo.

How is the speed & transients? I know HD650 is not the fastest cans, is it possible to make them faster with amp?

 

[ButtUglyJeff]

  How is the speed & transients? I know HD650 is not the fastest cans, is it possible to make them faster with amp?

 
I wouldn't get your hopes up too high, its the nature of the headphone...

 

[FredrikT92]

True, but I like to get it more livly atleast  

 

[pietcux]

True, but I like to get it more livly atleast  

I will give them a go tonight.

 

[fquails]

Just bought two brand new HD 650s--one for the house and another for the office. Sadly, one sounded muddier and the treble more subdued. The other HD 650, however, is heavenly. I spoke with Senn tech support, and I was told there will be variations between individual units. Anyway, I am returning the muddier one, and will receive the replacement tomorrow. Hopefully the replacement will sound as great as my other 650.

Got the replacement, and it sounds amazing right out of the box--just like my other one.  I am happy now.  Too bad the storage box had some damage in one corner.  Unfortunately, I returned the muddy ones (and its perfect storage box) before I received the perfect replacement phones and its damaged storage box.  Oh well.