These are my first mid-fi headphones. An RME ADI-2 DAC fs (with ESS Sabre chip) is the source.

I listen to many genres, from reference classical recordings over jazz fusion to ambient and EDM. I often watch movies and series, and occasionally play games. I rarely listen to rock, pop or metal, but even that happens from time to time. If anything, my ideal headphone is an all-rounder.

I’ve had many lo-fi headphones (AKG K240 studio, AKG K271 mkII, Beyerdynamic DT-770 80 ohm, Beyerdynamic DT-770 250 ohm) and one thing they all had in common was a focus on the treble range. As long as I was using dark sounding sources (Lavry DA-10, SPL Crimson, SPL Creon) that wasn’t a problem. But when I upgraded my source, I could no longer stand the treble on the DT-770. I tried EQ but somehow I still got listening fatigue from them. So I was looking for a replacement that sounded a bit warmer and found many recommendations for Harman target headphones.

My first attempt was the AKG K371, and I was (and still am) totally happy with them. They are comfortable and play well with the ADI-2 DAC fs. The resulting sound is balanced, warm, fun, non-offensive, musical and involving. In short: easy listening. But coming from those treble monsters before it, I got used to hearing lots of detail retrieval, and in that regard I find the K371 lacking. And when listening to certain cutting-edge genres of EDM, I found the bass a little too relaxed and slightly sloppy. (Especially compared to the hard-hitting bass of the DT-770!)

Hence my search for an upgrade. Seeing as I am so happy with them, I’m keeping the K371 for those times when I need a closed headphone. (My surroundings get really noisy at times.) But I use headphones so often (8 to 14 hours a day) that I think they are worthy of a modest investment.

At first I tried Beyerdynamic DT-1770 and I was totally underwhelmed. Their tonal balance is totally dominated by the bass. The rest of the spectrum sounded quite refined but otherwise not very exciting to my ears. At the time when I tried it, I wasn’t into EQ and so I returned it. I then tried Beyerdynamic DT-1990 and to me, they presented a clear upgrade over the DT-1770. But try as I might, I couldn’t get used to the treble range. I used the balanced pads for their warmest sound signature, and oratory1990 EQ curves for Harman target response. This resulted in a highly engaging sound, at times hyper-realistic and very exciting. But I still couldn’t get used to the treble. Somehow the 5 to 7 kHz region sounded metallic, and 6 to 9 kHz sounded grainy to my ears. After half an hour of listening, I had to switch to the easy and welcoming sound of the much cheaper K371.

So I tried the R70x. And at first I wasn’t really impressed with them. I mean, yes, they had that same warm (Harman) tonal balance as the K371, and there was a lot more detail, much better instrument separation, a better soundstage, and somewhat better bass. They do everything quite right and nothing quite wrong - there is no doubt that it is the better headphone! It’s just that I wasn’t excited about it – I had expected a non-fatiguing DT-1990 and instead I got something more polite, somewhat softer and a bit slower. Applying Jaakkopasanen AutoEQ curves for the R70x made the bass a lot bigger and the treble a bit more exciting. Very nice, and exactly what I was looking for. And still, I’m not excited by what I’m hearing.

Meanwhile I’ve been listening for a few days and I’m still not excited by the R70x. They are extremely well-balanced, absolutely not fatiguing while still presenting a clear and detailed treble range, they have a big bass, and they really work well for any and all genres. But I have to say that I’m amazed by their ability to “disappear”. I’m totally absorbed in listening to my music collection, and I forget that I’m listening to headphones. I’m not gloating over “details that I never heard before” or “the club-like punch”, instead the whole of my diverse music collection is respectfully presented as just that: music. I’m hearing performances and compositions more coherently than ever before. I’m not analyzing the sound of this or that instrument, instead I’m analyzing the song structure and feeling the emotional impact of it. The recordings are presented with enough credibility to support suspension of disbelief, while at the same time not distracting me with unnecessary details. They get to the heart of the matter, and that's something that I've never heard before in a headphone.

I would therefore say that these headphones strongest points are their holistic ability to present the forest instead of the trees, that they just play nice with any and all genres, and their magic trick of getting out of the way so I can totally immerse myself in the music.

Some negatives: comfort wasn’t good at first, I have a big head and the clamping force was simply too much for me. So I bent the metal headband outwards, so that it clamps a bit less and now they are very acceptable. The earpads are on the small side for my ears, so someday I’ll probably upgrade to Brainwavz, but for now I can live with it and I’m wearing it for hours on end without much thought. And they sound really nice without EQ, but adding in that sub and a little air (20 kHz) does transform the listening experience for the better.

If I could change anything about them (apart from the earpads), I would definitely want a speedier bass response and perhaps a slightly snappier transient response. Otherwise, I think the strong points of these headphones absolutely warrant their price and I think I can safely recommend these to anyone looking for an open all-rounder with a neutral to warm tonal balance. (As long as they have a neutral and powerful source that can drive them.) Some people call these end-game and while I could still imagine a slightly better headphone, I get where it’s coming from and I totally see myself being happy with these and not feeling the need to upgrade until they break. But I’ve only joined Head-fi a week ago so we’ll see how that goes :-D