I absolutely love my ATH-M50 headphones, but I was able to take a quick listen through the new ATH-M70X. They sounded fantastic. Really clear sound with their ability to separate the instruments spatially in the mix something I noticed immediately. They also sounded much flatter with less of the deep bass that the M50 has.

So, is anyone using this regularly as their reference/monitor headphones when mixing? I'm in an unavoidable situation where I have to mix through headphones and am curious what others think of these. Most, if not all, of the reviews from people online are from casual listeners, not people who mix music. Any thoughts on these? Worth the upgrade from the M50?

I bought them. They sound great. Now I have to spend some good time with them while working, not just listening. I can already tell they will be a huge improvement over the ATH-M50 due to their increased clarity and sound separation. :)

Interesting.
 
I've been using the ATH-M50 almost daily for years, it's like my Adam Audio A7 I don't think I could do without them.
 
The M70x have less sensitivity though and cost double as much as the M50. I think I'll wait for a special offer.

Well, you guys have me beat, I've been using the M40x and even these are great sounding for the modest price. I'm not mixing with these as a general rule, but they are great for monitoring when you're at the mic. They also extend my working curfew  when everyone else in my house are asleep!

I've been using them for 2 weeks now and I absolutely love the ATH-M70s. The M50s served me very well, but there really is a huge difference in sound separation and clarity between the M70s and M50s. Unfortunately, I live in an apartment complex that requires me to use headphones at all times so I have no choice but to mix through headphones. After years of doing it I've gotten used to it, and I felt like I was doing a pretty good job through the M50s. But after writing and mixing my first full track using the M70s, I have to say that it feels like these things make decisions for me. I'm not guessing as much when making EQ choices, or panning choices, since I can hear everything so clearly now. I really recommend giving them a listen if you can find an audio place that has a set out that you can try. Just bring in your iPhone or whatever you have loaded with a couple of tracks you're intimately familiar with (preferably something you wrote and/or mixed yourself) and take a listen. :)

I use the ATH M50's too, I like them, but I struggle to wear them for any long duration, a little fatiguing on my ears and not super comfortable as the as when I first put them on. I've been wondering about open back headphones, especially when the weather is hotter here.
 
The ATH R70's (their open backed option) look well out of my price range an so will probably be between the AKG K610's or Beyrdynamic DT990's. Then using the ATH M50's more for mic work.

Depends on what you are using them for. If critical listening is your thing (such as when mixing) open backs are generally fine. You just have to be a little more careful if you are using them to monitor while laying down any tracks that involve an open mic and the headphones in proximity to the mic element. I ruined a good take once doing the "one headphone in your ear the other hanging in space" like I was in some 70's TV show ,playing rock star. The bleed through made some weird pseudo flanging phase thing, that was just present enough to be irritating. closed back provide better isolation from that.

I got my first pair of open-back headphones a couple years ago, and it makes even the best closed-back cans sound like mud.
 
Sennheiser HD280Pro is still my favorite for tracking, and the ATH-M50s remain my everyday headphones for editing, but no mix is declared "done" until I've tested it on the open-back Sennheiser HD-580s. They are so comfortable that I regularly fall asleep wearing them.
 
However, I have yet to hear ANY headphones at any price point that I'd consider neutral enough to serve as my sole reference.