[BrianPeppers]

I have both of these headphones in my possession now. I'll probably be selling the DT990 soon so anyone want a detailed comparison before I sell them? Quick comparison:
HD600 is full, lush mids, sound feels closer to your head, more intimate and relaxing. Not as exciting for some music. Tone is much more accurate - they sound very natural and realistic. It sounds like an old, but expensive hifi set your grandfather has. These are brilliant but there is something "old" sounding about them.
 
DT990 has great soundstage, good bass, highs are great with some music. Recessed midrange and vocals sound distant. Very harsh highs - hard to listen to for extended sessions. Color/tone is off - these headphones sound very mechanical, which is great for some music (bassy electronic does well), but for most music there is something "off" about them. They sound very cold and German, in a sense. Brilliant for music and games - the soundstage is great and the mechanical sound of them does well for machine gun fire. Overall the sound is like you're in a movie theater. 
 
Also I have DT770 Premium 32 ohm. I can summarize them by saying that they are crap, but with better midrange than the DT990.

 

[rids57]

My old, well worn DT990s went back in their box within a day of my HD650s arriving, the relative harshness in the highs was too much to bear.

 

[BrianPeppers]

  My old, well worn DT990s went back in their box within a day of my HD650s arriving, the relative harshness in the highs was too much to bear.

That's right. Putting on the DT990 after the HD600 makes me cringe.

 

[brandonlyz]

Actually I beg to differ.
 
The DT990 pro does have a pretty sharp treble, but I'd say its more detailed than harsh. From my personal experience, the sibilance only comes about when low quality music files are being played. Even 320kbps does pretty well with these cans. 
 
The midrange may sound recessed but I've found that only to be due to the incredibly wide soundstage which pulls the mids further away, and coupled along with the more intense bass and treble responses may cause the midrange to sound slightly less present. However, I've found that if coupled with the right amp [especially tube amps or the Ifi ican amp], the mids gain much more body, which leads to an extremely pleasant listening experience.

 

[BrianPeppers]

  Actually I beg to differ.
 
The DT990 pro does have a pretty sharp treble, but I'd say its more detailed than harsh. From my personal experience, the sibilance only comes about when low quality music files are being played. Even 320kbps does pretty well with these cans. 
 
The midrange may sound recessed but I've found that only to be due to the incredibly wide soundstage which pulls the mids further away, and coupled along with the more intense bass and treble responses may cause the midrange to sound slightly less present. However, I've found that if coupled with the right amp [especially tube amps or the Ifi ican amp], the mids gain much more body, which leads to an extremely pleasant listening experience.

I think the amp has a lot to do with it. I've used these with Schiit Magni + Modi stack and that doesn't seem to be the best pairing.

 

[Shaffer]

I think the amp has a lot to do with it. I've used these with Schiit Magni + Modi stack and that doesn't seem to be the best pairing.

Agree 100%. The better the amplifier - source excluded for the moment - the smoother the 990s sound. My gear is listed in my profile. The only amplifier I have that matches less than well with the 990s is a Fiio E7. This being said, it acts as a sonic eraser with everything else I own, too.

 

[KG Jag]

The DT 990 is a well built mid-fi can with a "fun" "V' shaped sound signature.  It's good at what it does.  It is bright--too bright for many.  It's bass is EQed up, something that many, especially in the younger demographics, like.  It's Achilles heal is it mids, which are very recessed.  If you happen to like things like vocals and guitars, there is a significant problem.  If you want to hear a track the way it was laid down, you won't get that.
 
On the other hand, the HD 600, originally the Sennheiser Flagship, as been around since 1997.  It has been called the most important headphone ever made.  After more than 15 years on the market, it still sells in great numbers, even while being cannibalized by its sibling, the HD 650--which has been around and selling strong for more than a decade.  This grandpa of modern headphones is on Tyll's Wall of Fame.  The HD 600 registers close to neutral, with a slightly warm sound signature produced primarily because its treble is dialed back a bit from neutral.  It ably handles almost any genre of music you throw at it, although if you need a fast headphone there are better choices.  It scales up with better amps.  It just sounds damn good.  I own two of them.  See:
 
http://www.innerfidelity.com/content/very-important-sennheiser-hd-580-hd-600-and-hd-650
 
and
 
http://www.head-fi.org/t/634201/battle-of-the-flagships-58-headphones-compared-update-audeze-lcd-2-revision-2-6-4-13#user_HD600 
 
P.S. I also love the former Beyer Flagship the DT 880, especially the 600 Ohm flavor.  I own two of them (plus a 250 Ohm version I keep at my Aunt's home) too.  See:
 
http://www.head-fi.org/t/634201/battle-of-the-flagships-58-headphones-compared-update-audeze-lcd-2-revision-2-6-4-13#user_DT880

 

[Shaffer]

I can only comment based on my own listening experience, having lived with the cans for over a year. Others are free to derive their impressions in any way they wish.

Edit: ATM, I'm listening to DT990 via a Vio V200 using an Oppo105 as the source. There's no way anyone with a degree of perspective can refer to the sound as overly bright. FWIW, I own the HD600, as well.

 

[Xerber]

Agree 100%. The better the amplifier - source excluded for the moment - the smoother the 990s sound. My gear is listed in my profile. The only amplifier I have that matches less than well with the 990s is a Fiio E7. This being said, it acts as a sonic eraser with everything else I own, too.

How does the 990 perform with e.g. your LD MK3? I can imagine a tube amp can counter some of the harshness, no?

 

[Shaffer]

How does the 990 perform with e.g. your LD MK3? I can imagine a tube amp can counter some of the harshness, no?

The tubes I chose for the LDIII offer a relatively neutral tonal balance, not unlike [my] Corda Concerto. The LD, however, delivers more air, a greater sense of depth and separation. It can be more alive sounding, if you will. The Vio V200 is a much warmer sounding amplifier. In terms of harshness, I find it to be a product of poor amplification (and source material) - as in driving the cans with my laptop - or even with a Fiio E7, which in itself is a pretty mediocre performer. Too, keep in mind that I don't play lossy media at all - zero MP3.

Edit: In terms of personal preference, I like driving the DT990 with the Corda and the Vio. Mostly, I use the LD with HD600.

 

[Xerber]

The tubes I chose for the LDIII offer a relatively neutral tonal balance, not unlike [my] Corda Concerto. The LD, however, delivers more air, a greater sense of depth and separation. It can be more alive sounding, if you will. The Vio V200 is a much warmer sounding amplifier. In terms of harshness, I find it to be a product of poor amplification (and source material) - as in driving the cans with my laptop - or even with a Fiio E7, which in itself is a pretty mediocre performer. Too, keep in mind that I don't play lossy media at all - zero MP3.

Edit: In terms of personal preference, I like driving the DT990 with the Corda and the Vio. Mostly, I use the LD with HD600.

Thanks. That clears up quite a bit.
I was ogling the Beyer DT 990 manufaktur on their website. Oddly enough they are about the same price as a normal pair here in the Netherlands. Given that my LD is set up for warmth, I might go for it now.
Thanks again.

 

[MorrisL]

The harshness of my DT990 Pro has made me hate it with a passion. Always leaves me with a headache, and now I've realized that I can only tolerate warm sound signatures. But the question is: Is HD 600 warm enough? 
 
To be fair, on some music DT990 seems to be OK - usually well recorded rock stuff. I have yet to hear a classical piece that sounds enjoyable on these things. 

 

[mikey1964]

I have the DT990/600 which is the Premium version, listening to music using Foobar and an iFi Micro iDSD, I don't hear this treble harshness I see people talk about. I figured it has to do with two things, the Micro iDSD has a tubey or warm sound, negating some of the treble harshness of the DT990 or, this is more likely, my hearing is shot to hell....guess there's an advantage to being older than the demographics of the average forum members.

 

[Kalavere]

  The DT 990 is a well built mid-fi can with a "fun" "V' shaped sound signature.  It's good at what it does.  It is bright--too bright for many.  It's bass is EQed up, something that many, especially in the younger demographics, like.  It's Achilles heal is it mids, which are very recessed.  If you happen to like things like vocals and guitars, there is a significant problem.  If you want to hear a track the way it was laid down, you won't get that.

 
 
This just about sums up the DT 770's, I love 'em for gaming and media and I find them quite smooth for listening to music with, but I plan to pair my Lyr 2 with a Bifrost Uber in the New Year and shortly after the Q701 or K702's exclusively for music listening.

 

[brandonlyz]

  I have the DT990/600 which is the Premium version, listening to music using Foobar and an iFi Micro iDSD, I don't hear this treble harshness I see people talk about. I figured it has to do with two things, the Micro iDSD has a tubey or warm sound, negating some of the treble harshness of the DT990 or, this is more likely, my hearing is shot to hell....guess there's an advantage to being older than the demographics of the average forum members.

Agreed, I'm listening to it using the Ifi ican, and absolutely love them. However, I do hear bad experiences from guys who drive them using other amps, especially solid state ones. I guess that the Ican has a warmer sound signature which suits the DT990 perfectly.