After rereading the review and taking in to account some comments it received, i realised that some very important parts were rather vague. Like the neurotic i truly am, i decided to rewrite the parts that concern the sound, trying to be more precise and thorough this time around. I am looking forward to more of your opinions and constructive criticism.
Although Audio Technica is a well known and respected brand here, not many head-fiers had the pleasure to give the ATH-CKM70 a try. I was lucky enough to get these as a gift from James, so i decided to post my impressions on this relatively unknown iem. I will also be comparing them to the more well known Radius TWF11R, to offer a point of reference.
So, in the left corner, wearing a silver/black housing, and sporting a 12.5mm dynamic driver, a sensitivity of 106db, an impedence of 16Ω and a frequency range from 5 to 24,000Hz, we have the Audio Technica CKM70 :
(the Silver Surfer ...)
In the right corner, wearing a red/black housing, and sporting a 15mm dynamic woofer, a 7mm dynamic tweeter, a sensitivity of 105db, an impedence of 24Ω and a frequency range from 10 to 18,000Hz, we have the Radius TWF11R “DDM” :
(... vs Optimus Prime)
Build quality, fit and comfort:
Well, it's plastic all over, but durable and of a good quality. The strain reliefs on the cable are well placed and do the job quite well. The cable itself is good for a nylon cable and that's the only nice thing I can say about it. It has more memory than my pc, and microphonics are present, although to a lesser degree than i was expecting, thanks to its rather light weight.
(good build quality, relatively poor usability)
(the nozzle has an air duct on its base, try not to choke it when wearing them)
The most controversial part about the Radius is the fit. The nozzle of the phone is long and thick, so large tips are uncomfortable with the DDM. It also pushes allot of air, so tips that offer a tight seal are a no go for the non bassheads. They choke the airflow, making the bass too prominent and boomy, overwhelming the mids and masking the treble. After some trial and error, i found out that pipe shaped tips with a big aperture and a thin rim offer a very balanced sound with reasonable bass, that doesn't bleed into the midrange and lets you actually hear the treble. With these tips, the Radius, ironically, are the most comfortable iem i have ever used. They unfortunately offer very little isolation without music playing through them.
(small single flanges like these are highly recommended with the DDM)
(comfortable fit that doesn't choke the air duct)
The build quality is simply OMG for a pair of phones you can get today for around 80$ (from Japan). Aluminum and scratch resistant plastic have been used to create one of the most good looking iems i've ever seen (pictures don't do them justice). The cable is fat and sturdy, but also heavy, so although there is no memory effect, you will get allot of microphonics. On the up side, you can wear them over the ear without looking like a cybernetic life form (Radius I am looking at you), greatly reducing the aforementioned microphonics. Fit is nice and comfy, and isolation is average.
(pretty and sturdy)
(straight down looks better, over the ear works better)
The TWF11R offer a relatively thick sound that is a tad worm but well balanced. They also are, to my initial surprise, rather flat, as can be shown by their frequency response graph:
(graph shamelessly stolen from mobile-review)
Dynamic range is good but resolution is average. Having average resolution, they don't play all that well with badly compressed tracks. Distortion , especially in the mids, sounds prominent, as it masks most other contents in the frequency range.
Transparency is another area where the DDMs are lacking a little. The main perpetrators are their recessed treble and an unconventional imaging (more on that latter). Still, the DDM manages to produce an extremely detailed midrange and low end, so it's not all bad.
The 24 Ohms impedance makes sure that these are very easy to drive, but the Radius do love the extra juice when available. Background hiss is surprisingly inaudible for a low impedance iem.
Soundstage varies greatly from recording to recording. Although it can be quite intimate sometimes, it always retains an out of the head feeling to it. On the other hand, there are times when the soundstage becomes very wide, with an unusual depth for an iem, conveying both space and distance very well. Imaging is similarly varied. Sometimes it's fairly precise, sometimes the Radius take some surreal liberties with the direction of the sound, resulting in sounds coming from behind or above you. This may not suit the analytical freaks out there, but it's quite pleasant and immersive when it happens.
Sometimes, more often than not with mp3 joint stereo, the separation is lacking and the positioning is fuzzy. Instrument separation is also done unconventionally. Instead of dissecting each instrument, the DDM blends them together, layer upon layer, and manages to do that without sacrificing detail. You will still be able to tell the instruments apart, but the presentation will sound more like a live concert than a recording, sacrificing some transparency to increase immersion once again.
The bass is very well extended and detailed. It's more polite than punchy, and reaches very low. Quantity is a little more than i would prefer, but since it is polite, well controlled and doesn't invade the mids, it's easy to get used to. Attack speeds are better than expected considering their sound signature. They may not excel with very fast metal or electro but they can handle them. Decay and reverb are just right for natural instruments, but not the best for electronic sounds that sometimes have next to no decay. Drums, double basses and bass guitars sound very detailed and natural.
The mids are the selling point of the Radius. Prominent, full, very detailed and textured. Vocals and most instruments reside here and they sound excellent, conveying detail, along with plenty of emotion and feeling. If you like string instruments, this is the iem to get. The tonality, weight, depth, texture and fullness of pianos, guitars, violins e.t.c. is probably the best you can get in their price range. Vocals get the same treatment, with the exception of female vocals in the soprano range, due to the DDM's frequency dip in the high mids.
What deserves a special mention is the extreme detail of the texture of the sounds here. Chorus, brutal vocals, distorted guitars and every other similarly complex sound is reproduced to perfection. The down side of this is that in some non ideal situations, like badly compressed music and/or low quality/underpowered dacs, the aforementioned detail can sometimes become a little grainy, detracting from the refinement of the sound. This isn't very noticeable though, and it can be completely avoided with good quality equipment and tracks.
The treble is plenty and well extended, but very polite (probably too polite for the treble freaks out there) and a little recessed. It's also very dry, demonstrating a difference between the tuning of the twitter and the woofer. This is probably a conscious choice, as the tweeter seems to be responsible for the minute details added in the texture of the mids. The side effect is that instruments like cymbals have little decay, and are positioned too close to the mids. Brash instruments and solo violins also lack sparkle. So if sparkly highs and airy cymbals are a priority to you, better look below.
The CKM70 produce a sound that is neither thick nor thin, neither cold, nor warm, if maybe a tad bright. They are also rather flat, neutral and balanced. Their frequency range, combined with a very good dynamic range, is impressive, allowing them to be a true all arounder. Transparency and resolution are two other areas the CKM70 covers very well.
Soundstage has a more fixed size to it compared to the Radius, and is on average a little wider but has less of a depth. Imaging is good and consistent, and the presentation is very airy. Stereo separation is also quite good, as is the separation of instruments.
The 16 Ohms impedance makes sure that these are very easy to drive, but there is a small quantity of background hissing. Amping them does offer some improvements, but the DDMs seem to benefit a bit more.
The bass is well extended, tight, punchy and well defined. Quantity is ideal, less than the DDM but more than something like the re0. Bleeding in the mids is non existent and detail is quite good. Attack speeds are greater than the DDM's and decay is shorted, but not too short. It can reproduce fast metal and electro well, without staying too far behind the DDM in tonality.
The CKM70 seems to also have a similar dip to the DDM in its frequency response, but this time it affects the low mids instead of the high mids. The mids in general sound smooth and clean. Where the audio technicas lack in texture compared to the DDM, they make up for with detail. An acoustic guitar might sound a little better through the DDM, but the CKM70 will allow you to better hear the sound of the plectrum plucking the strings. Timbre is also very good, close but not quite to the DDM's level.
The treble is simply great. Sparkly, with great extension and definition. The CKM70 manages to produce a good amount of detail here, without sounding piercing or harsh. Sibilance is also not an issue unless the recording already includes it. Saxes and violins are reproduced with a good amount of detail and the proper timbre. Cymbals sound wonderful, airy, detailed, with excellent decay.
Most iems in this price range, sacrifice some areas, in order to be great at some other areas. The DDM falls to this category. The good news are that despite some quirks, where the DDM performs it's truly excellent. If you are a performer of a string instrument, you will really appreciate the unbelievable timbre you get for the asking price.
On the other hand the CKM70 tries to serve equal portions of everything. The dynamic range required for something like this to work well, is not often found in iems that can be had for less than 100$. While the CKM70 can't quite reach the seer amount of detail of treble oriented analytical phones like the re0 or the CK10, it manages to offer a very good compromise between analytical characteristics and good presence in the low end. It may not truly excel in one single area, but it manages to be very good in all areas together. It won't alienate a basshead like a re0, or an analytical listener like an ie8 or even a DDM.
It's also carefully tuned to play well with everything you can throw at it. It's fast enough for speed/thrash metal and at the same time offers good enough decay for natural instruments. It sounds properly full when tonality and harmonics dictate it, without being too full for complex passages.
Which one do I prefer? It's hard no to like the CKM70, it is an excellent all arounder, that performs very well across the whole frequency range. Still, most of the time I find myself using the Radius instead of the Audio Technica offering. I just can't get enough of their awesome timbre.
Which one would I recommend? The CKM70 does everything right, plays by the book in both sound and fit, while offering an excellent build quality. It's the safest choice between the two, and an even better bargain than the DDM for its current asking price.
Edited by SkiesOfAzel - 10/17/10 at 11:44pm