I'm auditioning the AKG K712, Sennheiser HD650, and the Shure SRH1840. Any fans of these out there? I'm going to choose one (or none), and send the others back. I'll post what I think of these as well, along with which pair I keep. However, I'd like to know if anyone here has one or more of these and what your opinions are.

I use Sonarworks Headphone Reference 3,  as long as they have modeled the headphones you use... brand is not relevant. but that said.... ;) it has to be a personal choice.
 
Peace! 

you should throw these into the mix:
http://www.musiciansfrien...p;kwid=productads-adid^221957295803-device^c-plaid^323968794223-sku^J44355000000000@ADL4MF-adType^PLA
 

I don't think there's really anything such thing as a "reference headphone". They are all lacking in some regard, at least every one I've ever owned, tested or researched. Then again, I've yet to explore the $1000+ category.
 
That said, all three of those models do sound good, and I'd have no problem editing or kicking back in the dark with any of them. I love the sound of the HD650s, and my current favorite cans are their similar siblings, the HD558, which in turn are close to the sound of the AKG K712.
 
I just wouldn't trust them as any kind of reference, whether we're talking spectral balance or simply hearing what a mix might sound like on generic headphones. You might want to think about another of the 650's close cousins, the HD600, which is close but avoids the hyped bass (+9dB) of the 650.

I have just sold my AKG 712.
they didn't sit tight on my ears, and soundwise imo the low freq are not enough.
also AKG seems to be known for a midrange boost which does not help using them as reference, I think.
but for hearing mid and high freq detail they are fantastic I think, and they have an awesome space/width.
 
Now still using the Senheiser 280, and a new pair of Shure SHR840 which to my ears sound almost the same (suprisingly) and the Shure maybe has a bit nicer width and less bass farting at loud volume.
And liking a new pair of Audio Technica MH40's, although they have a quite too much around 80Hz (to my ears, just guessing it's around 80Hz) but I get used to it after a day or so,  they sound really great, super 'warm'.
For the money too they're killer headphones soundwise and for build quality, comfort.
 
Never heard the Shure 1840 or the Sennheiser 650 unfortunately.

So, I did my shootout this past weekend, and here's what I found.

But first!
As I was heavily criticized for using headphones as reference on my FB posting, I want to clear the air. My main monitors are not headphones, but rather a few different sources.  For Mastering, especially, and some mixing, I mainly listen to a set of 1989 set of Polk Audio 2.3TLs (the line that made them famous, along with the 1.2TLs) customized with Soniccraft crossover caps, Goertz flat ribbon speaker cable, powered by a Pass Labs X350 with a $150 hospital-grade power cord (just to be funny), and Star-Quad mic-cables with Neutrik connectors from an Apogee D/A. I also have a set of ver.1 Mackie HR824's, my '08 Acura TL with the Elliott Schiener ELS system, a 1982(?) Radio Shack/Archer boom box, a $10 Walmart BT mono speaker, and a set of ATM40fs headphones. It's not surprising how reviled one can be by even contemplating such a blasphemous farce as mixing, or worse, Mastering on a set of cans. So, yeah, I heard a lot of that over the weekend. 

Still, even when you truly get to know your speakers in your room, you still won't always hear literally everything you need to. I use head-phones for critical/clinical objective concerns vs. the more subjective. And what I can hear on these sets is pretty awesome. Listening for artifacts is much easier on a revealing set of cans without the distracting air between the speakers and your ears. But, what it also reveals is whether a certain mix appeals to me one way with the speakers, and a different way in the cans, thereby allowing me to stop and ask why. Reverb/delay decisions can better be made on good cans in some cases.

Shure SRH 1840 - These were the "best-sounding" of the three to my ears. They were also the most comfortable. I could hear every detail I was hoping to, and felt I was really part of the music. They were probably the most elegant design, the easiest to set down on a desk, and they provided hours of great listening comfort without fatigue. They were the most "hyped" sounding in the bass/treble of the three sets, and they felt more closed-back of the three---hyped is very relative. These aren't hyped at all when comparing to such disasters as Beats by Dre, for example. I felt I could make the best 'critical' choices on them, in cleaning up problems. Subjective choices, however, might lead me to produce a mix with slightly weaker deep bass or kick and perhaps a softer top. Still, I love them!

Sennheiser HD650 - These were more natural sounding than the Shure's. I felt a great balance across my hearing spectrum without listening fatigue and without any feeling of hype. Only the tight head-band made me take them off. Otherwise, I was perfectly enjoying them. They sounded more open-back than the Shure's, but less open-back than the AKG's. I wanted to give them their diligence in time as I did the Shure's, but unfortunately, they made my head and ears hurt. Even so, they are superb!

AKG K712 Pro - Probably the most natural of the three, if not distant. These are designed to be more relaxed in a way where the audio you hear is more like listening to actual speakers and less like listening to headphones. Some find the audio a bit weaker in bass, and a little brighter on top. I found them, not weaker in bass, but rather un-hyped. If you listen to the final chorus of Close To The Edge (live) from Yes's Keys To Ascension II, when Chris Squire uses the sub-frequency bass pedals, the AKG's produce those frequencies clearly and un-hyped, but still powerfully. The Shures would vibrate my ear lobes. I also found them less bright than the Shure's, but on par with the Sennheiser's, if not a little less present. There are some areas of bass and treble I have to focus a little harder to hear as clearly as the Shure's, but again, I felt this merely to be less forward, allowing me to concentrate more fully on the midrange frequencies. These were the loosest comfort in wearing them, and the cans were rather large but they never felt flimsy or as if I would fling them off too easily. 

What did I choose? Actually, I haven't yet, although I heavily leaning towards the AKG's. The reason I gravitate to them the most is that, when I take them off and listen to my room speakers, these are the closest approximation of that experience of the three sets. And yes, they do sound more like listening to speakers vs. head-phones. The Sennheiser's are out only due to the uncomfortably tight head-band. The Shure's are truly good, but I can't really get past the more hyped sound I experience from them.

For tracking, I swear by mt ATH-m50x's. I recently bought a pair of Beyerdynamic T1's. OMG, they sound so awesome, but I would never mix with them.
 
Regards,
Dan

Found those AKG's for drastically less than other retailers:
 
https://reverb.com/p/akg-...w_wcB&hfid=6345585

brconflict
 

Shure SRH 1840 - These were the "best-sounding" of the three to my ears.  They were the most "hyped" sounding in the bass/treble of the three sets

the biggest mistake you could make,
would be to insist that headphones that are 'hyped' are good for 'reference'

batsbrew

brconflict
 

Shure SRH 1840 - These were the "best-sounding" of the three to my ears.  They were the most "hyped" sounding in the bass/treble of the three sets

the biggest mistake you could make,
would be to insist that headphones that are 'hyped' are good for 'reference'

You may have read too much into that. I did try to clarify that my use of the term, "hype" is very relative, in that they aren't hyped when compared to headphones that are notably and deliberately hyped. However, the Shure's did exhibit a slightly fuller bass and slightly hotter treble than the others. Again, these differences are quite subtle. If you read a lot of articles regarding Reference headphones, no doubt you will come across a few that state speakers, headphones, monitors, amps, mics, pre-amps, cabling, and yes, even electrical cords exhibit some difference, where the buyer subjectively will hear a difference more than objectively.
 
What could sound more natural to my ears, such as the AKG's, might sound distant or veiled to some who might find the Shure's more accurate. The choices are quite subjective. One can swear by one brand/model, while another won't touch them. But that's what makes this process so fun.