Apos x Audio Technica ATH-R70x Refine Headphone Review

edit: pretty sure that's a flat plate measurement (I could be wrong), but is it raw or is it comped to B&K 1dB/oct curve?

Distortion surface is always fun to try and draw correlations with but I'm a fair bit more curious about burst response for this one TBH, the more open designs of those A-T headphones have always been pretty lithe sounding to me, just lacking that sense of massive momentum you get with the Focal kids. Curious how well this one scales going up the ladder because I know one person who mainly uses these and prefers them to the HD600s and is currently lurking this thread (sup hah), but they're more "objectively inclined" so shame that these benefit from tubes (unsurprising though, the ADX headphones always seem to have a bit of an edge that need blunting).

How much brighter is the treble relative to a stock (JAR?) HD600 though, and how well does it do depth *layering* compared to the same on a setup that can actually do spatial presentation? Kinda curious if these have the same sort of responsive feel that the higher-end supra-aural Grados-- I figure you'd be the best judge of that.

LMAO that sharpening effect sounds familiar. Guessing less heavy-handed in how it does that compared to the old HP-3? No microdynamic compression going on with these, though, or loosey-goosey flabbiness in the driver transients?

Shame this is just a limited run of 1k, wonder how close you can get pad rolling the originals to approximate these.

 

@purr1n oh hold on: https://www.superbestaudiofriends.org/index.php?threads/audio-technica-at-r70x.678/

 

I fully agree with @purr1n that this is a great product--nice saturated but non-fatiguing tonality, open sound (impressive soundstage width), plus the absence of HD650's veil. It has effectively diminished my desire to get JAR650. Additionally, it is quite light and comfortable to wear. Overall, the sound signature is like that of an MJ3 in the headphone realm.

 

I'm out of the loop... is "Apos" a rebranding of their lineup? a designer/massdrop style collab?

 

Apos is primarily a retail company but has recently started doing collabs somewhat in the style of Drop:

https://apos.audio/collections/apos-x

Somewhat unfortunate name - have to remember it's Eh-pos, not a-POS

 

I just remembered there's also Epos that's done stuff with Sennheiser. Mildly confusing.

 

I liked the OG R70x back in the day. Felt pretty bass-light but reasonably neutral and it imaged better than the HD6XX-series. Good to see that someone's resurrecting them. And they had super high impedance/sensitivity combo which would make them interesting for OTL drive.

 

@purr1n This is a purely selfish request borne of curiosity thanks to chats I'm having with other folks at the moment but have you ever tried checking differences in distortion at the transducer level out of different amps? The Piety v Midgard comparison showed no difference in distortion put out by the JAR600 but that's not too shocking because it's -90dB vs -115dB THD+N i.e. pigeon fart-levels.

ONLY IF you have the time and inclination and this won't hold a tour up: I'm kinda curious how distortion surface or even just the old 2D distortion visualisation on the R70x might change between a measurements-first amp and e.g. an OTL.

 

Too bad it’s North America only. This headphone ticks a lot of boxes for me

 

Nice to see that the R70X is still getting some attention. I'm really curious to hear this revised version. I owned the original and I really liked it. I sold it for a dumb reason though. There was very little aftermarket cable support and I could not find any balanced cables. I honestly wish I still had it. I might pick the Apos version up.

 

Hah! May be worth spinning this convo off to another thread but really, this all does tie in with the few times I've gotten to try "horrible" measuring tube amps over the years (nevermind that some nonetheless sounded alarmingly clean, moreso than a lot of well-measuring SS amps I've tried).

This is honestly just more just me being a proper butthead and asking whether there were graphs and measurements I could present to folks who can't demo stuff for themselves or, even then, use that selfsame confirmation bias to decide for themselves even before listening to something that it'd be a distorted mess when the topic of tubes comes up.

In other words: feel free to ignore. I just figured the R70x was a particularly interesting headphone to try and test that out because of how it's effectively suspended in free air with that open baffle, and I was genuinely curious whether the original R70x's high D2 rise in the low bass (not sure how the new one will compare) might be exacerbated by a lower damping factor.

I might try and be useful generating my own measurements of the HD600 out of an OTL if I can get hands on one, just none too familiar with places where I can demo one (at least a quiet enough space that I can get somewhat useful distortion measurements, even if only on the MiniDSP EARS rig).

Sorry for the off-topic, back to lurking this!

 

The burst response is probably some of the more intriguing things that I think warrants more exploration, much more correlatable with how things sound than the old steady square waves InnerFidelity used to publish stuff with and yeah this seems to track well with your old subjective impressions of the older R70x and other folks' impressions of the same.

Your conjectures about red circled points' implications seem to hold up when looking at another open baffle design but one that seems to kick a bit more readily. Have never heard an Elex but the Elear and Clears I've gotten to demo seem similar in that they aren't shy about smacking you upside the face but don't necessarily over-linger (at least out of the amps I got to pair them with at assorted points, can't remember details). The Elex has that point in attack at basically all points sans circa 1500Hz :



Kinda reminds me about this actually, yeah you actually want a bit of overshoot that's quickly damped:



SOURCE: https://www.stereophile.com/content...-dt-880-250-ohm-and-dt-880-600-ohm-headphones

 

These showed up a lot quicker than Apos promised in their pre-order process, so kudos to them for that. The ZMF Caldera pads I ordered at the same time weren't in the box, so presumably those will arrive later.

Just to get this out of the way up front, the stock cable is nads. It's super microphonic across a regular cotton t-shirt, and I really don't like how it sounds either. I ordered a set of these adapters up front and I'm glad I did. Once the cable situation was sorted, the sound profile is... fine, and I suspect that breaking in either the drivers, the stock pads, or both will be beneficial. Comfort is exceptional, in part just because it's so light.

Plankton/micro-detail is present but takes a step back compared to more resolving headphones like the Clear OG or HE6se. Whether that's actually a loss of resolution or just a matter of the presentation not being as in-my-face about it is something I'll have to determine over longer listening sessions. Bass is fairly well controlled for a dynamic driver but doesn't have physicality to it, nor is it as precise as the Clear or HE6se, or even the DT 1990. Vocals have a hint of shout in the higher ranges and are otherwise reasonably natural. Upper mids into lower treble are fairly energetic, too much so with the stock cable to the point of fatigue. Upper treble/"air" sounds like it has some unevenness to it, which probably correlates to the present but not accentuated transients. Soundstage is great but not exceptional, and imaging takes a bit of a hit due to the more relaxed presentation of details/transients.

I'll keep these at my desk for the week, and hopefully by the end things will have loosened up a touch and the positives will start shining through. Right now I'd summarize these as being a bit like a dynamic Edition XS but without the crap build quality, which is very reasonable for the asking price as it is.

 

I'm going to take exception to this. The important thing to remember about distortion is that it is nonlinear. That means that it's introduced by processes that don't obey the laws of linearity, and you can't assume that it remains linear under composition either in the voltage or the frequency domain. Even putting aside the non-compositional nature of it, the two systems might also be introducing counterphase distortion, meaning that you could actually end up with less distortion overall instead of more.

This is why measurements of distortion are just that: measurements in one particular scenario. They can't be used to characterize a system unless you know and can model the mechanism by which the distortion is introduced.