I haven't seen graphs for either. Sadly manufacturers numbers are never more than marketing gibberish.
If it helps, I did saved CK10/CK100's FR graphs from Sonove's japanese blog on my computer previously so I have uploaded them for you, because sometime around Christmas last year through a japanese friend's kind gesture I came across a chance to purchase a new pair of CK100 for just 25,000 yen (approx. 310 USD), when brand new boxed ones in Japan (lowest retail according to Amazon Japan's prices) are still retailing typically for close to 33000 yen (approx. 410 USD) excluding of overseas shipping fees from Japan to Singapore. IMO it was a no-brainer question to me as I had a chance to audition the CK100 sometime back in Taiwan during one of my vacation trips there back in 2009 and was very infatuated by the magical and lush sound coming from this pair of IEMs, but ultimately I still had to do my own homework and contemplated really deeply on whether I should purchase the CK100, since back at that time I just bought the DBA-02 from Fischer Audio, and was pretty satisfied with its sound. (which has a rather similar and analytical sound presentation same as what the CK10 offers) Below the CK10/CK100's FR graphs are the Westone 4's graphs also taken from Sonove's blog, since he did wrote
a blog entry about it earlier in March shortly after its domestic release in Japan. (for W4, red & blue lines are the L/R channels of Westone 4, grey line belongs to Etymotic ER-4P as Sonove is a fan of Etymotic Research IEMs, so he will always reference using them as a guideline against newer IEMs) AFAIK, Sonove's FR graphs can be reliably used as a form of reference guideline as it's has been brought up for talk discussion on many japanese BBS such as 2chan before, and from what I understand he does use proper microphones to record each individual IEMs for each respective frequency response test.
I can't really advise or comment on whether the Westone 4 or ATH-CK10 would be a better choice for your case, because as someone else had already mentioned on this thread, most of us hear things rather differently and we have our own subjective tastes when it comes to sound preferences, how one hears an IEM may not be exactly the same experience as what someone elses hears when it comes to the same model of phones. What I can only provide is my personal experience and sound perspective, on what I feel personally regarding the CK10 and also coming from someone who had owned the DBA-02 before (just sold them off not too long ago actually).
I can probably elaborate abit on both the CK10 and DBA-02. Both of them do share quite similar sound signature traits, but I won't say if they are similar enough to be considered twins separated at birth though. In my own words, CK10 probably has more subtle and able to reveal more micro-details than DBA-02, having more of that neutral response across the frequency range (in respect, I would say the CK10 is much more similar in genes when compare to phones like CK9/ER-4S/ER-4P if you would like a direct comparison from me) while the DBA-02 is a much more balanced phone that allows you to enjoy your music more, with more quantity of the lower-end response in regards to bass (the quantity amount is still no-where near dynamic-based IEMs like IE8/FX700 though) but definitely sufficient in my books, that makes it a much more pleasant IEM to enjoy if your music do showcase them such as R&B rap and hip hop genres, compared to the CK10 which has quite lean bass (but still tight and controlled in my books) or probably to some people, a rather lackluster quantity of the bass impact in order to be able to enjoy those genres that requires a considerable amount of bass in order to be enjoyable/listenable.
In terms of mids, both CK10 and DBA-02 have rather neutral and flat mids, terms of frequency response. They have this aggressive, Grado-ish, in your face upfront treble probably akin to phones like RE0, so if you hate this kind of forward mids sound signature, with an energetic crisp highs with treble spike then both phones are probably not your kind of IEM. In terms of upper-mids and highs, the CK10 was able to demonstrate a much more airy, clean and articulate in terms of the sound texture compared to DBA-02, but that's only according to my own pair of ears, as your mileage may vary. Both phones have quite an impressive transparency, instrumental separation and precision speed, probably only second next to phones like Etymotic Research's ER-4S/ER-4P, which still gets mentioned in some of the well-known reviews benchmarked by the regular contributors on this forum these days.
Does that make either one a better choice over the other? Not really in my books, both IEMs are actually very enjoyable choices according to my own ears, but the reason I went for Fischer Audio DBA-02 instead of the CK10, was because I was already using the CK9, and was surprised at how similar the CK9 and CK10 were in terms of sound signature upon listening, except for the difference in that CK10 has a much better ability in showcasing better imaging, instrumental separation and those refined highs in terms of treble, some of these features which the CK9 was quite lacking of when compared to its newer dual-driver BA successor. Also for the fact the DBA-02 was much cheaper to acquire in my country when I was looking at new phones to upgrade over my CK9 back last year, so the modest street price really helps when I was making my choice over the CK10. (even though I'm a self-professed Audio-technica fan myself)
Anyway regarding CK10's build quality, I would just like to touch on abit more regarding this matter. From my previous findings on Head-fi according to
AwakenedBeing's review of both the CK10/CK100, both him and Happybuns did elaborate on some issues regarding CK10's poorer strain relief in comparison to CK100, also in the case of Happybun's scenario it seems that his own pair of CK10 did suffered from some exposed rubber sleeving on the strain reliefs near the housing shell, which seems to concide with some of the cabling build issues that I had read and
came across on
Kakaku.com, a popular japanese community BBS discussion forum. Not trying to say that this will definitely happen to your pair of CK10 should you go ahead and purchase it, but just something to ponder upon since from the time I had did my research on both the CK10/CK100, I had never came across any forum discussion or blog entries by japanese users regarding broken strain reliefs or cabling build issues on their CK100, but there was indeed
more of such issues happening to the CK10, if you actually do a proper search around Head-fi though I suspect it's mainly due to the lack of a proper strain relief on the CK10, and as current owner of the CK100 I have to say it does have a better strain relief design compared to CK10, so probably just something to ponder about in case you are considering buying the ATH-CK10.
Can't really comment anything on the Westone 4, as the only Westone IEM I had personal experience with is the UM3X and as far as I know, sound signature is considered to be quite different from the Westone 3/4. (just like how in my personal perspective, I would say that CK10 and CK100 both in terms of sound signature are actual polar opposites of each other)
Cheers.