Written originally in http://www.head-fi.org/t/738635/new-audio-technica-iems-ckr7ltd-ckr9ltd-ckb50-ckb70/30 thread on 4th September 2015.
Silly me because I just found out how to add new item for review, discussion purpose.
I bought the CKB50 through Aliexpress for just 26USD, free shipping. They described it as original CKB50 and even blurred out the AT logo. Just received it 2 days ago of course without original box, just come with extra 4 pairs of silicone tip. I have Sony XBA10 as my sole balanced armature earphone before this so I am excited to try this CKB50 as a comparison. This is no ordinary earphone even the specs shows impressive features like 65ohm impedence and a strange frequency response of 20hz to 15kHz. Even with high impedence it is still easy to drive with my HTC Desire 820s. But surely I have to crank up the volume to about 20 to 25% of total volume. My other earphones normally will need up to 10 to 15% volume.
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There is only one seller with only single gold colour CKB50 currently sell in Aliexpress. I have no idea whether this is truly original Audio-technica products or not. It doesn't matter anyway. Out of box/ or package in my case it already sound impressive. It has big and tight bass sound. Definitely bigger than XBA10 or FXT90 but not as big as IM50. The vocal are clear and details are almost as good as XBA10. The treble is moderate at best not as sparklingly bright as FXT90.
Comparison with IM50;
IM50 is my 1st AT product bought BNIB at full price of 62USD so I am very sure that this IM50 is real original Audio-technica. It was my best earphone until I bought FXT90. The best thing about IM50 is the build quality. The cord is super tough but flexible. CKB50 cord is springy and not very flexible. Nevertheless there are not much different in SQ between these 2. Bass amount is slightly higher in IM50 but CKB50 is tighter. Details and treble are almost the same.
Comparison with XBA10;
XBA10 is my 1st ever balanced armature earphone. Bought BNIB but at a discounted price. Still very original Sony product. This is still my current king of details amongst my earphones. It sounds nicely balanced and details. CKB50 is only better in bass. Very surprisingly bassy for single balance armature driver.
Comparison with FXT90;
The 1st earphone I bought through Aliexpress. Same story selling as original FXT90 for 32USD. Sounds fantastic out of package. Moderate but tight bass, sparkling bright treble, good vocal and details. Good for any kind of music genre. CKB50 is better in bass amount and probably has slightly more details.
Addendum;
1. Fellow head fier in above mentioned thread suggested me to try Sony hybrid tip to get better bass response. I already tried that and the tip has been permanently stuck to the CKB50 nozzle until now. The tip is very comfortable and does really enhanced the bass until reaching the level of IM50 in term of quantity. But as I mentioned bass on CKB50 is tighter.
2. Comparison with Sony EX650 . My latest purchase after CKB50.
EX650 is rated as 2nd best currently amongst my earphones just below FXT90. But being built with solid brass means that EX650 is heavy and uncomfortable to use for long period especially for my right ear. If I happen to have long time to spend listening to my music surely I will pick up CKB50 or even FXT90 over EX650.
Conclusion.
A very good entry level balanced armature earphone. I only wish that Aliexpress has CKB70 and FXT100 selling at OEM price like this CKB50 and FXT90. Very secure and comfortable in ear even with half in ear design. Very fun sound signature. The cons are the springy and microphonic cable without any chin slider or shirt clip. Otherwise an excellent value at just 26USD.
