In general, my impressions of these headphones line up pretty well with the other people who have reviewed it. In general, I’m really happy—no, maybe “thrilled” would be a better description—with how they sound and think Audio-Technica has a winner here, though there is some room for improvement, particularly on the ergonomics front. What is definitely not in my review is a detailed comparisons with other headphones, as I don’t own/haven’t recently heard very many other things in a similar price range.
I’m also not going to bother with pictures of the unboxing, either, because this already been done very well by previous reviewers: @earfonia, @twister6, @hakushondiamao all have good pictures of it. I will have a couple pictures later on, though, when I discuss build quality.

General Sound Signature
To echo the other reviews: these are very neutral-sounding cans. That is, there’s no particular frequency range that seems either pushed or recessed. I’m really looking forward to seeing good measurements on this because the impression I have is that the frequency response is very flat. Not bright, not dark, just neutral. Well, maybe just a small touch of warmth, but it’s pretty subtle. I’m very familiar with the Audio-Technica V-shaped “house sound” and these do not have that. It’s a whole new sound signature for AT.

Bass is very tight, well-damped, and clear. Not muddy at all. Extension is very good. They are not, however, particularly bass-heavy. For example, if you’re familiar with the AT M50s, well, these don’t sound at all like that. If you want a lot bass, you should look elsewhere or be ready to hit the EQ. On the plus side, these deliver more bass than my HD595s, and that’s a good thing.

Highs are not harsh and again very well-controlled. Good clarity, in good balance with everything else. @earfonia has commented that he’d like more treble for classical recordings, but I don’t find that to be the case. However, my classical tastes are more for quartets and chamber music, not full orchestral music, and that may be a factor. I generally find bright headphones to be a little too much for me with violin-heavy recordings, which is what you typically get in string quartets. However, I haven’t heard the HD800s that earphonia prefers for classical, and those are out of my price range anyway. I’m perfectly happy with the R70x for classical, though I will concede that it isn’t their absolutely best genre. (I will guess, though, that these are, in fact, really good for opera. I personally can’t stand opera, but these do such a great job with vocals that I would think they should do well there.)

Where these cans really shine is in the midrange. Good articulation, very natural tone. Vocals and guitars sound particularly good. If you really live in the midrange, but don’t want to really compromise the highs and lows to get them, then you should definitely give the R70x a listen.

Now, the danger with with some transducers is that, in an attempt to get something that sounds flat in terms of frequency response, everything sounds kind of washed out, or sounds too analytic. AT did not go that route here: these are involving headphones that really draw you into the music. They are neutral without being boring, which I think is a real achievement for $350.

Imaging and Soundstage
These are not detail monsters but they image very well. Great separation between instruments, everything distinct from each other. These headphones have a particular property that I’ve never really heard in other headphones that’s a bit difficult to explain. They render acoustic instruments very well and in such a way that the difference between real and synthesized instruments are particularly noticeable, especially drums. I am much more aware than usual when a drum machine is being used, and I find myself wanting to listen more to music with natural percussion.

Soundstage is nice and wide with good clear placement, but maybe a little less deep than would be ideal. They do have the strange property that sometimes—not often by any means, but every once in a while—things stage such that they actually sound like they’re coming from the back. It’s a little weird, but not unpleasant.

Smoothness
This is another place where these headphones really shine. Smoothness vs. detail is a place where non-kilobuck headphones typically struggle. My HD595s, for instance, were pushed too hard to try to get more detail than I think they could really manage, and the result was grainy. Detail retrieval for the R70x is very good, but it’s well within the capability of the headphone, meaning the sound is very smooth. (This is the single biggest improvement over the HD595s I’m used to: dramatically improved smoothness while at the same time with better detail). Silky smooth. They really get out of the way and let the music come through.

One of my earliest sessions with these headphones was a “well, I’ll just listen to my standard test tracks and then stop” and ended up listening for three solid hours before noticing that it was 2 a.m. High marks for being involving, non-fatiguing headphones.

Driveability
They are 470-ohm headphones; you’re going to want an amp. To be honest, I expected these to sound absolutely horrible without an amp and was somewhat surprised. Sound quality is definitely compromised, no doubt about it—bass response and detail retrieval definitely suffer—but it’s not a total disaster. Still, if you are planning on listening without an amp, I’m sure there are better choices than the R70x.

Comfort
They are light, they have comfy pads, they don’t make a lot of head contact, and they don’t clamp particularly hard. So, as you might guess, they’re very comfortable. However, I don’t think they’re more comfortable than my HD595s, even though the HD595s are heavier. I think the 595s have better cushions. Still, though, I’ve always thought the 595s are the most comfortable full-size headphones I’ve worn, so being tied with those is still high praise.

Sizing
I have a pretty average-sized head, and there is not a lot of clearance left on the top of these headphones. I can easily imagine that people who have somewhat larger heads would not find these headphones comfortable at all. So, if you do have a larger-than-average head, definitely find a pair of these and try them on before you buy, because they might not work for you.

Labeling
If your goal was to label left and right on a pair of headphones, but do so in a way that would be the most difficult possible for someone looking for those labels to find them, you’d probably end up doing something close to what they actually did. It’s a terrible location with horribly low contrast—simply inexplicable. Seriously, someone should lose their job for this. You will either need to mark the headphones in some way or rely on some other aspect of them to know which one is which. It’s not like that’s the end of the world or anything, but this would be so easy for AT to fix. Bad design is bad.

Cable
Other reviewers have complained about the fact that these only come with one cable, and it’s rather on the long side. This isn’t an issue for me, but I can see how it could be for other people—if this is the kind of thing that bothers you a lot, be warned. My only real beef with the cable is that it’s a Y-cable, and I much prefer a single-side cable.

Isolation
I think it’s really weird that people comment about this for open-back headphones, but I’ve seen it. Here’s the scoop: they’re open-backed headphones. They isolate almost not at all. That’s how open-backed headphones work. I guess maybe some isolate a little, but that’s not to be expected, and these don’t isolate much at all.

As of this writing, there aren’t many reviews of the R70x on Amazon, and the overall score isn’t very high because of a couple reviewers who have issues with the build quality. I think it’s hard to really know exactly how well-built something really is until it’s had to face the test of time, though if something feels bad right out of the box, that’s not usually a good sign.

The R70x certainly don’t feel particularly substantial. I don’t take that as them being flimsy or poorly-built, instead it strikes me as an intentional design decision to save weight. AT wants these to feel light on the head, and one way to do that is to make them, in fact, light. So they aren’t very substantial. They don’t feel particularly fragile, so I don’t have any immediate concerns about build quality, but I do think there might be cause to put them in the “wait and see” category.

That cause, as raised by one of the Amazon reviewers, is the stitching on the pads. When viewed from the front, these actually look fine:



However, when viewed from the back, well, things aren’t quite so neat and tidy:



Now, I don’t think pad stitching is in and of itself a huge deal. However, it does make me worry that other parts of quality control that are less obvious may also be compromised. So, I’m going to wait and see how they hold up. Now, I’m not particularly rough with my at-home cans (different story for the mobile stuff), so the bar doesn’t have to be all that high, but still, it is at least a potential concern.

So, the ergonomics are less than ideal on some scores, but the sound signature and overall sonic performance are pretty much exactly what I was hoping for. These are, for my money, terrific headphones. Now, I haven’t ever heard any of the modern flagships (e.g., the HD800 or the HE-6) and I’m not looking in that kind of price range anyway, so I can’t say how well they compete with the top end, but I don’t think they’re really intended to.

I think these are aimed more at the midrange, like the HD650 or the Beyer 880/990 or the AKG K701. It’s been a while since I listened to anything like those, but from what I remember, I’m pretty confident that I’d take the R70x over any of them, simply because the neutrality of the R70x is so appealing to me. So if that’s what you’re looking for and have $350 to burn, I’d highly recommend giving these a listen.

Review Equipment
My primary listening rig is:

• “Wastebasket” style Mac Pro running iTunes and BitPerfect (almost entirely lossless 16/44.1 with some 256AAC and some high-res stuff as well)
• Optical out
• Schiit Bifrost Uber
• Schiit Magni 2 Uber

I also gave them a whirl unamped from my iPad Air (256 AAC) and amped from the Air with a FiiO E11.

Review Music
I listen to a moderately but not extensively wide variety of different music, mostly rock, electronica, classical, new wave, new age, and world. I detest country and opera, and while I don’t dislike blues and jazz, I own almost none. There’s a little rap/hip-hop in my collection, but not a ton of it. Here’s my current “test gauntlet” that I put all new gear through multiple times, which has a good mix of different genres as well as different things I’m looking for when I listen. Some of these are fantastic recording and some are, on purpose, somewhat subpar, because I want to know how things perform there as well:

• The Art of Noise, "Il Pleure (At the Turn of the Century)" from The Seduction of Claude Debussy (1999)
• Nine Inch Nails, "Into the Void" from The Fragile (Right) (1999)
• Tool, "Stinkfist" from Ænima (1996)
• The Cult, "Wild Flower" from Electric (1987)
• Tears for Fears, "Start of the Breakdown" from The Hurting (1983)
• Michael Hedges, "Breakfast in the Field" from Live on the Double Planet (1987)
• Rodrigo y Gabriela, "Hanuman" from 11:11 (2009)
• George Winston, "Spring Creek" from Summer (1991)
• Janine Jansen, "Concerto No.2 "L'estate", RV 315; III. Presto" from Vivaldi - The Four Seasons (2004)
• Hahn/LA Chamber Orchestra/Kahane, "Concerto for 2 Violins, Strings and Continuo in D minor, BWV. 1043: I. Vivace" from Bach • Concertos (2002)
• The Power Station, "Some Like It Hot" from The Power Station (1985)
• Underworld, "Little Speaker" from A Hundred Days Off (2002)
• Thomas Newman, "Root Beer" from American Beauty (2000)
• Shadowfax, "Oasis" from The Odd Get Even (1990)
• Tori Amos, "Precious Things" from Little Earthquakes (1991)
• The Police, "Every Little Thing She Does Is Magic" from Ghost in the Machine (1981)
• Propaganda, "Strength to Dream" from A Secret Wish (1985)
• Pink Floyd, "The Happiest Days of Our Lives" from The Wall (Disc 1) (1979)
• Zoe Keating, "Escape Artist" from Into the Trees (2010)
• Rene Lacaille & Bob Brozman, "An Dio" from Dig Dig (2002)
• Fleetwood Mac, "The Chain" from Rumours (1977)
• Paul Simon, "Homeless" from Graceland [Bonus Tracks] (1986)
• Sting, "Driven to Tears" from Bring on the Night (Disc 1) (1986)
• Nine Inch Nails, "Came Back Haunted" from Hesitation Marks (Audiophile Mastered Version) (2013)
• Deepsky, "View From a Stairway" from In Silico (2002)
• Pink Floyd, "One of These Days" from Delicate Sound of Thunder (Disc 2) [Live] (1988)
• Moby, “Bodyrock” from Play (1999)

Reviewer’s Background
I will admit that I am first and foremost a speaker guy. My most prized possession after my car are my Ascend Acoustics Sierra-1 NrTs. Nonetheless, before I had those, I first got into headphones back in 2004 when my second child was born. I like to listen to music while I work in the evenings and he was a light sleeper, so I got into headphones a little—only a bit, as my budget was a little tighter than it is now. At the time the big battle in the Head-Fi world was Sennheiser vs. Grado, though Beyer and AKG and Audio-Technica were around, they weren’t the big noise at the time.

I auditioned the HD600s and whatever the similarly-priced Grado was at the time (I want to say 325s). I couldn’t stand the Grados—far too aggressive and bright, horrible bass roll-off, and also really uncomfortable. But, to be honest, I wasn’t really thrilled with the HD600s, either. A little too dark. My ideal audio setup is completely neutral and accurate everywhere. No coloration. I want to hear what the engineers recorded, not some modified version of that. The best amp, as far as I’m concerned, would be “wire with gain.” (I don’t like tubes for this reason.) I want speakers/headphones with as little coloration as possible. I don’t want them to be “fun” or “laid back” or “bassy” unless that’s what’s on the recording. I listen across several genres and I’m not interested in having one set of cans for genre X and another for genre Y. The best way I can see to do that is to be as neutral as possible.

Now, unsurprisingly, I’m not alone in wanting this, but unfortunately it’s probably not quite achievable at what I consider to be realistic price points. There are always compromises. What I’m usually looking for is the least compromised piece of equipment I can get at any particular price point. That’s not for everyone—and that’s fine. I just want folks who reads this to know where I’m coming from.

Anyway, back in 2004, as far as I could tell, the best compromise for under $250 at the time was the Sennheiser HD595s. Not as dark as the HD600 family, certainly less bright than the Grados, and very comfortable to boot. The compromises: grainy, a little plastic-y, and not quite enough bass—but great for the money and for what I wanted at the time. We ended up moving to a new house in 2006 with my study not so close to the young one’s bedroom (and he grew into a sounder sleeper), and I spent dramatically less time with my headphone rig and invested in a pair of speakers that I adore.

However, for a variety of reasons, I’m back to headphones for a while every night, and have a little more spending money, so I wanted to jump back into something nice. The R70x had just come out, and the early reviews from @earfonia and @twister6 suggested this would be a headphone I’d like, so that’s how I got here.