After 3-ish weeks of living solely with my new 009s, I went back to my much loved 007 Mk1s to confirm the winner
(...)
The 009's have simply stunning lower mid to bass performance. They're pretty stunning higher up too, but the clarity and focus in the lower mid to bass regions really highlights the 007s main weaknesses IMO, making the latter seem thick and muddy in comparison - in fact, quite hard to go back to. It's not a tonal thing, it's about clarity, focus, transparency, dynamics.
Others have said that the 009s have a bigger sound stage, which is true, but what I particularly noticed was how clearly all the secondary images were laid out within that larger sound stage, which gave them more equal billing with the main central vocal image. This leads me to the one consideration: It's quite easy to get distracted by all that extra secondary detail - and thereby forget to listen to the actual musical performance. With the 007s (and just about every other 'phone I've heard) the secondary images recede relatively backstage to the central vocals, so are less likely to distract.
The solution is quite simple: stop marveling at the details and start following the musical performance - I've made this mental switch a number of times mid-track and the extra detail then merely serves to enhance the performance.
So, are the 009s perfect? Not quite. I'd still like them to have a slightly darker overall presentation, and I'm not the only one who's unimpressed by that over-sized plastic arc mechanism. And highly panned left or right images feel like they're being directly injected into my ear. But for the foreseeable future, they're perfect enough for me. My 007s have been long-term relegated to their storage case, as the best emergency back-up headphones ever.
YMMV. I listen at modest levels (mid-70s-80s db), my hearing tails off after 13KHz, and the rest of my system has been carefully chosen to control excessive brightness. As others have said, the 009s are transparent enough to show up deficiencies elsewhere in the chain.
This aligns with my impressions of the 009 vs the stock 007 Mk1. I really appreciate that you have spent long enough time with both for making a verdict, and I think this makes it quite valuable. Now the way you expressed the differences triggered a thought... You may remember that I am using 009 pads on the 007. The differences you describe here apply pretty well to the pad change from 007 pads to 009 pads. I am not saying that the 007 becomes like a 009 by using a 009 pad- the 009 has a larger and thinner membrane and different driver, and it's logically expected to have more resolution, better stage and better bass; what I am saying is if someone likes the 007 but wants it more open, with wider and more clear imaging, with a slightly different but still better bass, try the 009 pads. It's a move in the right direction. I know that it changes to volume the 007 membrane has to move, etc - but it just sounds better to me.
I didn't stop at that, and after some hesitation, I have changed the internal foam of the 009 pads to a similar shape carbon foam pad filling I "developed" for my Fostex TH900. This is a fully reversible mod on the otherwise horribly expensive 009 ear pads. The sound changed in the same direction it did with the TH900, a veil was lifted, and the sound became so open and detailed that it was almost too much midrange detail. I was fine with it, discovering new layers and lights of the music, and bass improved too, but I was missing the speaker-like physical low end punch of the TH900. I could trade-off some midrange for more and deeper bass impact. After many days, I managed to form a foam size/shape that does what I hoped for: the bass now had much more perceived low end energy compared to what it was, and the overall sound was still very transparent and open. What I want to mention here: in the process of cutting off half mm chunks of material from the carbon foam, I noticed a strangely big sound stage change around a certain threshold, and that I could describe it very much alike you did with the "secondary images": the sound stage just snapped open, as previously isolated lateral sound information blended into the whole, creating a huge, wide, deep and tall, contiguous, very enjoyable sound stage. The effect depends on recording, but with some recordings (e.g. Stockfisch label) the difference was kind of on/off.
I intended to make a post about this, with pictures, but let me still test it for a longer while.
The question begs to be asked, how far is now my modded 007 Mk1 from the 009, and it's no easy one - I hope to find out soonish, the nearest head-fi buddy is a flight away from me, but it's hard to find time. However, my 007 sounds so good now that I don't feel much inclination to just find out that I need to double my headphone investment
, when I am still in a new honeymoon with my 007. At least I would not like to trade this kind of bass I am hearing for what I remember from the 009, even though it was better than the stock 007... My TH900 and my speakers are not getting much listening time nowadays.
In turn, and that's likely even more interesting question: how would the 009 sound with my modded 009 pads? Both on the TH900 and 007, the carbon foam seems to change the sound in a similar direction, which most 009 owners may like: more extended, faster and even more transparent bass, bigger and much better defined sound stage, much improved microdynamics (small percussions attack/impact/decay, clarity of piano key hits, body of cello, etc), less muffled and more open sound (which may not be needed for the 009).
I have no idea when I will travel to England next time (I actively avoid traveling nowadays), but if any of you 009 owners come near Helsinki, remember you are welcome to an audition.