After about 12 hrs of listening and comparing to Clear OG and 5909, here are some additional impressions:
Sound:
it is a bit of a marvel how big the
soundstage is. After much listening, they are closer to Clear OG than to 5909. The IO-12 connected to my iPhone via AAC compare well to the Clear OG (plugged into Gold Go Bar with balanced wires hooked to my MBP listening to Apple Music lossless). The main improvement of OG is that they are a little more resolving. The IO-12 connected via USB adds a little more resolution. Frankly, I may sell my wired setup of I keep the IO-12. From 50s jazz (Kind of Blue) to Mahler orchestral music, the IO-12 have far more presence, stage, height, and are immersive in ways the 5909 cannot compete.
My favorite recording of Mahler's Symphony 6 "Tragic" is Szell and the Cleveland Orchestra (1966). The older recording loses power on the 5909. Re-listening to it on IO-12 I found the original thrill of the opening. I think that some older recording where details are a bit lost, the soundstage and dynamic range are crucial to make up for it. When it comes to
detail and
resolution, there is plenty in IO-12, but not at the expense of musicality. I think the 5909 sometimes serve details at the cost of musicality--there is a certain sharpness and clarity that is a strength, but also a weakness that makes some parts hurt your ears, forcing you click the volume down a bit. That has not been the case once with IO-12. With IO-12, everything seems detailed but round.
I never feel like an instrument is trapped in one ear cup with IO-12. On 5909, sometimes there is a beautifully detailed instrument that seems unnaturally stuck inside a spot in my ear cup. The IO-12 gets everything out of the ear cup.
There is one other thing that stands out for me: there are
no dead spots on the soundstage on IO-12, but there are some on 5909. Say, in the recent remaster of Ellington's Money Jungle, in the Fleurette Africaine track there are moment where at 3 o'clock there seems to be nothing on 5909, like a sound gap in that location, but on IO-12 you are surrounded by the music.
Listening to choral music like Messe de Tournai with Ensemble Organum (HarmoniaMundi, not on streaming it seems), there is an airiness that captures a bigger space. The IO-12 are more like a grand church and the 5909 like a chapel. On track 3, with the IO-12 the choir doesn't just get louder, it expands and fills the space. On 5909, it just grows louder.
Comfort:
Very good. They stay in place better than 5909 at about the same comfort level. The headband is a little more comfortable on 5909 as the cost of not staying in place. The earcups are a little more comfortable on IO-12.
Ergonomics:
Some may bemoan the absence of an app, or touch controls, etc... But these are the most ergonomic headphones I have had, except for H95. I realize, for instance, that I almost never use the headphone controls with the 5909, instead relying on my phone. With the IO-12, I only use the headphone controls. Power on and off is a breeze. Volume control and skips work perfectly). And tones/voices are perfect volume. (5909 tones are too loud, pausing doesn't always work on first press, and powering on and off is a pain leading to regular mistaken BT pairings or headphones staying on or not powering on because I did not hold buttons long enough.)
Multipoint:
It works perfectly. BT connection range is comparable to 5909, which were my previous the reference (Bathys have a substantially shorter range than either of those).
ANC:
Somewhat comparable to 5909, but a far cry from APM. Fine for home use. Did not test enough, but the fullness of the IO-12 allows is to better mask outside noise. TBH, I plan on just getting some Bose QC Ultra for travel when I find a pair on sale.
Early Conclusion:
The IO-12 make music I don't even like interesting to listen. In fact, it makes music I think more of as noise sound like music to me too.
@angelom 's post above is unlistenable to me on 5909. Just noise to me. The guitar section at the 3:41 mark is unpleasant and stuck in my ear cup on one side; there is no coherence. The IO-12 makes it music, albeit not my taste.
I think I will be keeping these, and possibly selling my Clear OG. These are the closest wireless headphones that feel like listening to speakers (and closest to feeling like open backs).
