Tips: Small silicon tips
Build: Colored resin.
Comfort: Perfection. 5.6mm at the lip.
Isolation: Fantastic.

Bass: Low sub bass, solid mid bass, BA bass, missing DD tactility and dynamics. 6/10

Test tracks:
Chameleon - Trentemoller
Sadness, Pt. 1 - Enigma
They Just Haven't Seen It - San Holo

Midrange: Good lower midrange, uneven upper midrange, big dip in presence region. Vocals are recessed and muffled. 4/10

Test tracks:
Crazy - Daniela Andrade
My Work - JFDR

Treble: Peaky mid treble, low air. Presence dip makes it stand out. 7/10

Test tracks:
Red Light Zone - Colonia

Tonality: 5.66/10 (B-)
Tonality is flawed but wholly listenable without EQ, if not fully enjoyable.

Detail: Solid details, probably helped by 6kHz peak. 6/10

Test tracks:
Midnight (Kygo remix) - Coldplay

Imaging: 7/10 Precise. Very good. Soundstage: 5/10 Somewhat narrower.

Test tracks:
No Excuses (MTV Unplugged) - Alice in Chains

Dynamics: 6/10 Solid. Bass is good for a BA.

Test tracks:
heartsigh - Purity Ring

Technicalities: 6/10 (B)

Score: 3.0/5 (B)
Value: * (at €160)

It's a cool set with relaxed tuning that works without EQ. Surprising good mid bass, despite being BA. Great fit and isolation. Unfortunately, there was some technical issues (tweeters connected out of phase) and IEM died in less than a year. So in the end, I won't recommend it.

Tips: Small silicone tips.
Build: Resin body, metal faceplate and nozzle. Solid and light.
Comfort: Despite fat looking nozzle, comfort and seal is good.
Isolation: Very good.

Bass: +13 dB at sub bass (20 Hz). Gradual slope into lover midrange. The bass bleeds into mid and is uncontrolled. However, it's power and dynamic is unrivaled. 7/10
Test tracks:
Chameleon - Trentemoller
Sadness, Pt. 1 - Enigma
They Just Haven't Seen It - San Holo

Midrange: Harmanesque rise with a 4-6kHz dip. Clean but recessed. Allows higher volumes to accentuate the bass. 5/10
Test tracks:
Crazy - Daniela Andrade
My Work - JFDR

Treble: Dark. Touch of sibilance in mid treble. Recessed in air. Tinny, gritty treble, typical of biodyna drivers (ala Fostex). It doesn't obtrude the bass. Don't need EQ. 4/10
Test tracks:
Red Light Zone - Colonia

Tonality: Bassy. Impressive midrange clarity, despite mega bass tuning. Very inspired tuning. 5.333

Detail: Bass detail is great. I've heard things in bass parts, I haven't on any other set/ Midrange is very good and clean. Treble is bottlenecking it. 4/10
Test tracks:
Coldplay - Midnight (Kygo remix)

Imaging: Good. 5/10 Big soundstage. 6/10
Test tracks:
No Excuses (MTV Unplugged) - Alice in Chains

Dynamics: Great dynamics. Bass is really pushing this up. 7/10
Test tracks:
heartsigh - Purity Ring

Technicalities: Surprisingly technical for the price point. 5.5

Score: 5.42/10

Value: ***/3

Unique sound at the price point. Most fun bass I've heard in audio. Sound puts you in the drummer seat while still keeping midrange clear and audible. You will hear details in the bass parts you've never heard on any other set. Tuning is inspired, doesn't need EQ and loves high volume.

Worth the blind, if you are bass head or already have a budget neutral pair and want something fun.

Build: Light but strong. Nice, polished look.
Comfort: Light. Small. Great fit, they don't fall out. Seal is great.
Isolation: Vented. Isolation is very good, despite the vent.

Bass: +11 dB at sub bass (20 Hz). Gradual slope in the mid bass. Boost in the sub bass area so it doesn't impede the mids.
Midrange: Lower mids are perfection. Slightly relaxed upper mids.
Treble: +10 dB 8kHz peak. Fantastic air unheard of in many 50x more expensive sets. Too sharp in the presence region, bound with big midtreble peak gives piercing sharp sound, especially with larger volumes.
Tonality: B-

Tuning is very good in general. Boosted in the sub bass, great mids and great extension. Two peaks cause sibilance with higher volumes. Treble sounds thin and unnatural. Cymbals sound plasticky.

Detail: Very smooth sound. Controlled and precise.
Imaging: Somewhat veiled, which impedes with the imaging.
Dynamics: Wonderful dynamics. You really feel that bass. Rarity, especially with budget sets.
Technicalities: B-

Clear, detailed and dynamic. Fantastic for the price. Game changer.

Score: B-

Value: 14.57 EUR with the mic. Worth the blind.

vs Olina
------------
Two recent giants in their price category. CRA is new king of the budget v-shapes ($15), Olina is the interesting new entry in the $100 bright neutral category. They are in the very different price categories, but let see how they are compared one to another.

Tips
----
1) Narrow bore S stock tips
2) S stock tips

Build and look
--------------
1) Olina is medium size and light, very beautiful with marble plate and shine, blue aluminum shell.
2) CRA is small and very light, with nice see trough resin.

1) > 2)
Olina wins it for me. Good build and I really like the look.

Comfort
-------
1) Good. Comfortable. Has some movement which needs readjustment.
2) Perfect. Small, very light. Plug n' play.

1) < 2)
CRA wins it here, but it's not that the Olina is uncomfortable. CRA is really small, light and achieve fantastic seal. Everything you expect from IEM.

Isolation
---------
1) Very bad. 2 vents per shell. Almost open back.
2) Very good. Despite having a tiny vent on an inner side of the shell, it does a solid block of the oustide noises.

1) < 2)
CRA wins it easily. It is in fact one of the best isolation on a vented design I've heard, yet.

Tonality
--------

Bass
====
1) Gradual fall from +6dB. Perfectly tuned. Warm, punchy, boomy bass.
2) Gradual fall from +13dB. Big, fun sub bass tuning. Not impeding into mids. Impactful. controlled, but overly boosted.

1) >= 2)
Olina is better in tuning and naturalness. Somewhat lacking in control. CRA would have impressive control, but that is mitigated by overly boosted sub bass. Olina is better by less exaggerated tuning and warm timbre. However, CRA bass is not far behind.

Test tracks:
Chameleon - Trentemoller
Sadness - Enigma
They Just Haven't Seen It - San Holo

Mids
====
1) Great. A little pronounced in upper midrange.
2) Great. A little tamed in upper midrange.

1) >= 2)
Both have greatly tuned mids. Olina wins on clarity, but not by much.

Test tracks:
Crazy - Daniela Andrade
My Work - JFDR

Treble
======
1) Excellent. Nice extension. A little hot in the presence region.
2) Problematic. Nice, uniform extension. Too sharp in the presence region, bound with big mid treble peak gives piercing sharp sound, especially with larger volumes.

1) > 2)
Biggest CRA issue. Despite achieving great treble response, tuning issues make it sharp, sibilant and unnatural. Olina can get hot in treble, but never crossing into sharp, sibilant territory.

Test tracks:
Red Light Zone - Colonia

Overall
=======
1) > 2)
Olina has great tuning over all registers. CRA has exaggerated sub bass, but done in a tasteful manner. Real problem is treble which, while extended, is sibilant and unnatural.

Technicalities
--------------

Detail
======
1) Very good.
2) Good.

1) > 2)
Olina is clearer and more detailed.

Test tracks:
Dire Straits - Love Over Gold

Imaging
=======
1) Solid.
2) Very good.

1) > 2)
Olina imaging is more precise and soundstage is much bigger.

Test tracks:
Nils Frahm - An Aborted Beginning

Dynamics
========
1) Very good. Bass punch is excellent.
2) Good.

1) > 2)
Olina wins it with refinement and excellent bass punch. CRA is very good with authoritative bass hits.

Test tracks:
Dire Straits - The Man's Too Strong
Chemical Brothers - Leave Home


Overall
=======
Technicalities are clear on the Olina side, but CRA is very good in detail and dynamics.

Value
-----
1) redefines the price bracket
2) worth the blind

1) < 2)
CRA is the greatest value in HiFi currently. At it's price it managed to make so much of that good, that nothing can be compared to it. Tuning, comfort, isolation, detachable cable, optional mic. Olina is great new contender in the $100 arena, it gets most of the stuff right and very little wrong.

Overall
-------
Olina
Pros: really big soundstage, great punch n' slam, comfortable build, great looks
Cons: abysmal isolation, which makes it unusable in the noisy environments, hot upper mids. Hot upper mids would be manageable on medium volume, but with low isolation this makes them unusable outside

CRA
Pros: comfort, fit, very good isolation, fun but clean, controlled and detailed bass, excellent mids, fantastic treble extension (rarity with single DD), very good dynamics (rarity at the price point), very detailed sound (unavailable previously at the price point), easy to drive, microphone (optional)
Cons: too sharp in the presence region, big mid treble peak, piercing sharp sound, sibilant, unnatural plasticky cymbals

Olina mostly wins easily in every category, which is to be expected at almost 7x the price, but it is surprising how much CRA gets right for so little money. If they managed to control treble a little more, it would easily be an end set for many.

Build: Wonderful, robust headphone, au pair or second to only DT770. Nice, industrial look.

Comfort: Excellent. Medium weight (at cca. 300g) but comfortable. Soft headband and pads. Robust and flexible mechanism. This is how headphone should be designed.

Isolation: Open back. You'll hear the environment and they will hear you.

Bass: Almost perfectly neutral. Open back that goes down to 20Hz without roll-off. About 1dB rise in upper bass.

Midrange: Very good. About 2dB rise in lower mids and big 6dB drop in the upper mids about 1.5kHz, but with little audible effect on tonality.

Treble: Excellent. 3.5 dB drop at the lower treble and 2dB rise at 6 kHz and 1dB in upper treble and air. Adding air while cutting hard edge on vocals. It can get sibilant, though.

Tonality: Bright neutral. S-

EQ: Not necessary. Great with Optimum HiFi. Add bass per preference. I love it with 4 dB boost.

Detail: Hard, fast transients. Fantastic clarity. This redefines the price bracket. There is no such a resolving driver under 1000 EUR. (Maybe LCD-2?)

Imaging: Good soundstage, precise imaging.

Dynamics: Fantastic, almost Fostex level punch n' slam.

Tech: A

Score: A

Value: Worth the blind. Best of Hifiman tuning, Focal technicalities, Beyerdynamic build and Sennheiser QC for the price of HD600. What are you waiting for?

Build: Solid.
Comfort: Excellent. Very light. Leather strap can pull hair, though.
Isolation: Open.

Bass: Roll off under 50Hz. Bloated midbass. 1.25/3
Midrange: Lower mids emphasis with upper mids fall decreases clarity of the mids. 1.5/3
Treble: 6k peak gives sharpness to the sound. 1.25/3
Tonality: Above average. 2.50/5
EQ: Needed. For my preferences, mandatory. Try Serious SBAF or Optimum HiFi +4dB.

Detail: Good. 2/3
Imaging: Fantastic soundstage, probably second only to HD800. 2.5/3
Dynamics: Below average. 1/3
Tech: MidFi soundstage king. 3.25/5

Bias: 3/3
Interestingly, this is probably my most used headphone. Why? 1) Comfort. Light, open and breathable. 2) Soundstage. Loving the openness of the sound, it is high on my enjoyment list. 3) It is clear and detailed headphone when EQd. With EQ fixing tonality issues, it really shines.

Score: 2.5/5

Value: Worth the price. In Europe you can now get it for about 200 EUR, which is great price for what it offers. In my local shops, price is more like 350 EUR, which is a different proposition. Of course, you have to value soundstage and comfort and be prepared to use EQ.

At last I managed to demo R70x. Balanced sound with dark tilt. Nice bass, solid soundstage. Feather weight, great comfort. Cups are smaller, then they look in photographs. Only long cable included. Hard to identify left-right cup. Somewhat insensitive, need stronger amp. Very enjoyable sound, but not on the detailed side.

Build: Heavy, robust IEM. Nice, industrial look.

Comfort: Heavy. (20g) It causes to break seal. Below average.

Isolation: Vented. You'll hear the environment, which interferes with the quality of sound.

With green filter:
Bass: +5 dB at sub bass (20-80Hz). Gradual downslope in mid bass. Great.

Midrange: Excellent. Perfect lower midrange. Slightly recessed lower midrange between 1.5k and 4k. Small 4.5k peak.

Treble: Very good. Small resonance peak. Air is recessed, though.

Tonality: Relaxed neutral. Fantastic. Sub bass could be more pronounced. Treble could be more extended. A

EQ: Not needed.

Detail: Hard, fast transients. Fantastic clarity. This redefines the price bracket. There is no such a resolving DD driver under cca. 600 EUR.

Imaging: Average soundstage, precise imaging.

Dynamics: Average.

Tech: A-
Bias: A-
Score: A-
Value: Worth the blind. At $200 they are unbeatable.

Wonderfully built, great look, great cable and case. JVC's 11mm DLC driver is a masterpiece. Price is fantastic, I got them at $200 and nothing comes close to it. ER4XR you can maybe get at $300 but has a BA bass and ety fit. Blessing 2: Dusk is $320 with better technicalities but FDX1 beats it at coherency and bass and Dusk has an even bigger nozzle. HS1650 has similar tech and coherency but at triple the price. Resolution of FDX1 is great with fantastic clarity that beats anything close to it. Tuning is great, wonderfully balanced. They look great with nice "industrial" design. Included case and cable are superb. At $200 they are unbeatable.

So is there any reason you should not buy it? No, but there are some caveats. They are heavy, which means if your ear canal is sweaty or oily, they will easily slip out. Nozzle is medium thick but if you rotate it right, they will fit even in small ear canal. (In contrast to B2, Variations, Monarch, etc.) Isolation is poor, which means you will hear the traffic around you which will somewhat defeat the wonderful sound and technicalities of the IEM. If I could change the one thing about them it would be the isolation.

Great build, robust, 2nd only to DT770 Pro. Love the looks. 3.5mm to 3.5mm cable with locks on both sides. Nice and practical. Medium to light weight at 315g. I have often found advices that these “need nuclear powerplant to drive”. I guess that probably sprung from the specification that they can take up to 3 Watts of power. However, I found them relatively easy to drive. I found no issue driving them from phone, tablet or laptop to impressive loudness. Sound is, there is no other word, smooth, comparing to the dynamic drivers. Like it’s missing the kind of grainy background that I notice on the dynamics. This model is exceptionally tuned, between 80Hz and 5kHz it has great adherence to the target. Sub-bass is rolled off and treble attenuated, but that is almost wholly fixable with EQ. They also sound great without any EQ. Bass sounds impressive, big and strong, maybe a little boomy but without overwhelming mids much. Thin pads puts the driver near your ear for best sound quality. Unfortunately, this bring us to comfort. Thin pleather pads and headband coupled with strong clamp makes them somewhat uncomfortable and sweaty, especially during hot months. Great entry to planar headphones and probably the best closed back HP for the price.

Build and package is great. Lots of tips, great cable, mic, ear hooks. Cable can be microphonic so use ear hooks and clip-on. This was my daily driver for more than 4 years, every day in pocket. Very sturdy. The sound. V-Moda V shape. Isolation was great, no port on this one. Bass was the best I heard on any IEM. But the price was recessed and unresolving midrange.

Bought it locally for a reasonable price. It's nice looking, solidly build, surprisingly comfortable and lightweight headphone. Pleather pads are comfortable, but not breathable. You will sweat, if wearing outside. It comes with detachable cable with microphone, stop/start button and analog volume slider. Nice. The sound. Well, this one's famous for it's Foster biodyna drivers. Bass impact is best in class. However, tuning on this model is far from balanced. Think something along the V-Moda M-100 line. Fun, but overwhelming bassy sound. While it can get fatiguing for music in general, for EDM / modern pop the bass performance is fantastic. Really, no other models I heard come near it. It is a big, physical, club-like experience. Higher frequencies are recessed, grainy and somewhat grungy.

When EQ'd it became a solid headphone. Somewhat dark tilt remains, however. Mids stay somewhat recessed. Soundstage gets wider and is solid for a closed back. Solid smooth sound, maybe missing detail a little because of the dark tonal bent. Higher frequencies stay coarse.

However, there was a problem, the connection on the 2.5 mm jack was cutting. I've returned it to the store, where they fixed the issue. Other than that, there were no issues.

Interesting model, it made me appreciate the Foster biodyna drivers. It is a specialist headphone, but for its narrow subset it really is incomparable.

This is a classic studio headphone. They have medium size soundstage, which is fantastic for a closed back headphone. There are not many closed backs with wider soundstage and good isolation, certainly, none in its price range. These are among the rare audiophile headphones that are not rolled off at sub-bass. Most of the open back and a lot of closed backs are having this issue. Not this one. Sub-bass is not only present, but boosted at 5dB which gives very fun sound. Unfortunately, this brings us to the main issue. The treble. Treble is piercing and fatiguing over longer listens. It's the infamous Beyer-peak at 6kHz. It gives the illusion of clarity and help catch sibilance during studio monitoring, but without EQ it is very hard to enjoy this one. With both elevated (sub)bass and treble this gives us a U-shaped signature which makes mids (hence, vocals) recessed, a common issue with V and U shaped signature headphones. All these issues are fixable with the help of EQ. Bass has a boomy quality to it which gives it power but takes away the resolution in the lower range. Velour pads are very comfortable, as is the headband. Build quality is outstanding, these headphones are indestructible, while still lightweight (270g). Isolation is very good. Unfortunately, cable is non-detachable which is the only build objection. However, cable is robust and extensible. One more, this is one of the hardest headphones to drive, so don't expect high volume from the portable sources.

Vintage AKG from the early 80s. Classic studio phones of the time. Clear mids and great imaging are the reason these were beloved by the studios of the time. Imaging makes them surprisingly good for gaming. They are light and relatively comfortable and surprisingly easy to drive, despite high impedance. You can easily drive them with mobile phone or laptop. Probable reason for that is abysmal bass extension. Sub bass is almost not existing. Soundstage is so narrow, it is almost nonexistent. However, this results in an extremely forward presentation. It sounds like you are on the stage with instruments right next to you. Despite overly boosted lower mids, sound is enjoyable during longer listens. The sound has somewhat plasticky timbre, not sure if it is caused by the tuning or the passive radiator system. Leather cups can get hot and uncomfortable during longer use under summer conditions. Cable is non-removable, as typical for the headphones of the time.

Perfection in comfort. Light, perfectly placed around the ears. Easy to drive. You can drive them from laptop, phone, tables to great loudness without any issues. Great accessories, one short 3.5mm cable, one long 6.35mm cable + 6.35mm to 3.5mm converter. Balanced sound with slight v-shaped signature. Little mid-bass bloat, little treble peak, but that's nitpicking. Resolution, unfortunately is mediocre. It's not on the HD6xx nor HD560S level, but it's the best of the rest of the HD5xx series. If you find them under $180, don't think twice. Great set!

Overview:

The CX 400 is high quality, noise-isolating ear-canal earphone with a powerful, bass-driven stereo sound for listening on the go. It's feature a short cable, perfect for use with mobile phones or MP3 players with a remote-control and/or microphone. With the included 1 m extension cable the CX 400 can also be used with a player carried in your pocket.

General Information
Technical Information
Miscellaneous
Earpiece
Physical Characteristics
Interfaces-Ports
Warranty

Review:

Solid, small, light, comfortable IEM. Ergonomics are really fantastic. Fit is great so reproduction easily goes to sub bass frequencies. Bass is elevated but not overwhelming. Veiled sound, lacking details.

Nice lightweight hands-free set with big bass emphasis. Unfortunately, everything else about the sound is bad. Dark, muddy sound drown by a big but bad sounding bass.

Recently, I've sent them to Oratory1990 for measurements and EQ. With this, T200A was transformed from the dustbin item to a contender. The bass was reigned in, midrange got presence and clarity. Treble is maybe a little hot, but never sibilant. Coupled with fantastic isolation, size (small and light) and comfort, it entered my regular IEM rotation. Also, it's bass impact is best of all my IEMs (probably thanks to it's unvented design). With EQ, I would give them 3.0 rating.