[rhythmdevils]

Give them some time.  The purchase will be useless if you just sell them before giving them a chance.  Even if you wind up selling them, you should get to know them better first. 
 
If you like the general sound of the HD650, but want less bass and more treble and more "clarity", you should definitely try the HD600.  Since you like the ath-M50, it seems you like a balanced sound signature, which is pretty rare in headphones, so I think trying the HD600 would be a good bet. 
 
But if you want a brighter sound than the M50, then you have lots of options.  Like a Beyer DT880 or an AKG or a Dennon.
 
I'm mystified as to why the HD650 doesn't sound more open than the M50.  Listen to the 650 for a while, and I bet you'll start seeing how the M50 sounds closed in.  But the M50 is very open and spacious for a closed can.

 

[NapalmK]

Definitely give it some time but if it ends up being meh then consider the Ultrasone Pro 750, Denon D2000, and Ultrasone HFI-780. All of these cans do exceedingly well with my trance and dnb.

 

[Kuze]

Definitely giving them time, i didn't really get them at first but over time i really started to like them, if the headband gets too tight there's a guide around you can read up on, plan on getting a good amp for mines soon.

 

[High_Q]

Does your amp have impedance settings?  For the longest time, I didn't like the sound coming out of my 650 with my tube amp which is Elekit TU882.  Until I read the long thread about my amp, and there was a really important information that totally changed my views on HD650.  I thought since the impedance of the HD650 is around 300ohm, it should have been set to high impedance(my amp has impedance setting switch on back).  Until I found a comment by the designer of my amp.  here it is:
 
[size=medium]Here is the comment from TU-882 designer Mr.Fujita : [/size]


Matching the impedance is important only to convey the power of the amplifier to the headset in most effective manner.

However, having the best sound quality is another story.

Matching the impedance could cause distortion and low damping. You need to see the balance of the impedance matching and good sound quality. 

As the said headphone, Senn HD650, seems to convey the power very effectively, it no longer has to be connected to high impedance. Connect it to low impedance and get the best sound out of it. Low distortion and high damping.

As you know, the vacuum tube amplifier has very low damping, 5 or 10 at most, compared to a semiconductor amplifier having 100-200 damping. Connecting it to low impedance could lead to high damping and low distortion, a better sound quality, which must be something that all users want to achieve. 

Also, TU-882R/AS is designed to best match commonly used headsets, and focusing only on those high-impedance headsets is not a good idea.

Could this explanation help the situation? I hope so...

Cheer!!
 
^I tried this and my HD650 is my favorite headphones now.

  I don't believe it is veiled anymore.

 

[tdockweiler]

With me, if I don't immediately like a headphone ( I give it a week usually), I sell it or return it. No point in wasting so much money for something you don't like. Of course this is after burning it in. Sometimes I'm so disgusted with the sound quality of a headphone that there is no way a burn in will make it sound that much better.
 
I remember buying the Sennheiser HD-650's and hating them. This was supposed to be an "upgrade" to my Beyer DT-990 and AKG 701 I had at the time and had been using for several years.
 
I basically gave up on the HD-650 and stuck with my Triple Fi 10's for three years since I was tired of buying so many headphones.
 
Once I got tired of the Triple Fi's I tried to find another good headphone. I ended up with the HD-600. I actually decided to try them out and felt that it was a huge risk. Strangely it was the very last headphone out of maybe 6-8 i've tried!
 
I actually based my decision on some frequency charts! I compared them side by side to the HD-650's charts and I like how the upper frequencies were not toned down (not as much as the HD-650 I mean) so much and that they had much less bass. I could have written down exactly what I wanted in a headphone and the HD-600's ended up fitting exactly what I wanted. One thing I love about them is that they almost never make my ears tired when listening to them for hours. Most headphones fatigue my ears in just a couple of hours, if not faster.
 
Anyway, based on the frequency charts, the HD-600 sounded like something worth checking into.
 
I think this is the first headphone i've had that made my want to invest in a really good headphone amp and not just use my expensive receiver.
 
It seems that a lot of people dislike the HD-650 and prefer the HD-600. Sometimes it's the other way around though. I honestly don't think I could stand any more bass then what's on the HD-600 for long listening sessions. I have the M50's and the bass can get tiring. I might end up selling them if I try out the Shure SRH-750DJ and like them. I've found the Shure SRH-840 sounds much better then the M50's but the fit is terrible.
 
My suggestion is to return the HD-650's and try out the HD-600!

 

[High_Q]

Although I finally figured out the right setup to get the 650 output its potential(I can't imagine being better), I think is kinda rediculous that such searching is needed to get it to sound right.  Instructions should come with the headphones for what is the optimal setup for the headphones.  It sounds incredible when the setup is right, I am so happy that I am able to hear HD650 at its potential.

 

[Shahrose]

1) Your source is really limiting the HD650s. Get a proper DAC. If you don't want to spend a whole lot of money, go for the Musiland 02US, which I found mated well with the 650s. So well in fact, that I believe it sounds comparable to setups costing 3-4 times more.
2) Listen exclusively to the HD650s for a few weeks and then switch back to your M50s, then you'll realize just how much better the Senns are. It takes time to pick up on the subtleties of audio. My impressions of headphones are usually quite different 1 month after owning them than they are at day 1.

 

[catscratch]

I'd say get a headphone that you like, and then try to max it out with associated components, rather than keeping a headphone that you don't like and trying to turn it into something that it isn't. I did some of that and it was ultimately wasted time and money. Granted, the HD650 is a headphone that can sound exceptional or terrible solely based on what rig it's in, but still, I would suggest moving on.

 

[Ro-amp]

OP, I hear the same thing as you...flabby & muffled, I removed the earpad foam not much of a change, I'm selling them.
Headphones makes the biggest difference in sound, if they don't sound right to you from the start, move on, don't waste time & money!
My SHR840 are such a great can, I'm looking for the equivalent open can for classical & jazz listening, I honestly don't know where to go from here, DT880, HD595, HD600, AKG 702???
Good luck
Cheers

 

[Mescalamba]

As I had them before for some time..
 
1) they need burn-in period.. long one .. they sounded quite nice after two-weeks (Im listening to music kinda non-stop). You dont need to listen to them, when they are in burn-in, you can load your system with your favorite music and simply let it play for 48 hours or so.. Or use pink noise.
 
2) they need proper amp or proper soundcard .. they are supposed to sound good with tube amps
 
3) cable should help, you dont need to buy something super-expensive, but better cable helps as that one which comes with them isnt really "top notch" quality
 
I think that they depend most on 1 and 2 points. They are "true" high-end headphones, which means they scale well as you upgrade your system. Unfortunately, they dont sound that well, until you do so.. I returned them back and maybe I will buy them again when I get Woo 6 SE or something similar. Or simply get another phones.. theres lot to choose.
 
Btw. Sennheiser have quite a bit of personality, so ppl who likes them usually dont like other cans and reverse.. I cant for example stand AKG 701, but HD 650 were much more to my liking.. not mentioning HD 800.

 

[Mescalamba]

Quote:

OP, I hear the same thing as you...flabby & muffled, I removed the earpad foam not much of a change, I'm selling them.
Headphones makes the biggest difference in sound, if they don't sound right to you from the start, move on, don't waste time & money!
My SHR840 are such a great can, I'm looking for the equivalent open can for classical & jazz listening, I honestly don't know where to go from here, DT880, HD595, HD600, AKG 702???
Good luck
Cheers

Sorry, but higher end (or high-end) headphones always need burn-in, for example AKG 702/701 needs LOADs of burn-in to sound good. There is only few headphones from higher-end that sounds good at first listening.

 

[SillyHoney]

The DAC will dramatically change your headphone (or more accurate, push it to its potential), not amp. I don't know about Thinkpad T500 headphone out but that of my Sony Vaio FW sounds ridiculous. But actually I only realized that after I hook up a Gamma-2.



And by the way, why your HD650 is $500? Isn't it $330-ish?

 

[High_Q]

Quote:

The DAC will dramatically change your headphone (or more accurate, push it to its potential), not amp.

I don't think that is true.  Amps are very important. Since amps cause distortions because of extra harmonics in the spectrum. Even with good DAC, bad amp will make DAC output signal sound really bad.  Assuming the output has decent headphones, the order of importance should be get good amp, then get good source(DAC). 
 

 

[Shahrose]

Quote:

Quote:
I don't think that is true.  Amps are very important. Since amps cause distortions because of extra harmonics in the spectrum. Even with good DAC, bad amp will make DAC output signal sound really bad.  Assuming the output has decent headphones, the order of importance should be get good amp, then get good source(DAC). 
 

I disagree. I've done a lot of amp and DAC swapping with the HD650s, and it wasn't until I got a good DAC that I heard a big improvement in its sound. A tubey tube amp can colour the sound enough to hide the flaws of a bad source, but getting a high-end transparent amp with a crappy source will result in crappy sound.

 

[Mescalamba]

You need both.. good AMP and DAC. Its called synergy.. if one part fails, it simply fails.. But even quite bad headphones can sound quite good with perfect DAC/AMP.