Summary – When it comes to reference neutral IEMs, I casually like to classify them in 2 different categories –
- The kind that present songs dead neutral, like how they were recorded, without any of the extra spice or sugar added from their side. In short, I like to call this ‘True Reference’, something that mimics flat frequency response studio monitors in a well treated room.
- The other kind that presents the songs very accurately with correct tonality and a reference balance but with a little added zing and sparkle that infuses energy, throwing you into the songs as if you’re watching the band perform right in front of you or even better, performing alongside the band. I like to casually call this ‘Live Reference’ because it creates an illusion of one listening to or performing the music in a live setting.
In my opinion, CE6 does the latter. It has a ‘very realistic’ reference-ish kind of presentation & tonality with a prominent upper treble lift. It follows the Harman Target curve till the upper midrange but with the same twist as the CE4, which is 64 Audio’s tia driver style of upper-treble. The upper-treble lifted character of CE6 which has even more amplitude than the peaks of tia drivers themselves makes CE6 very intriguing, lively and exciting with great clarity, realism and micro-detail retrieval but in some cases also highlights hi-hats/cymbals and vocal air/sizzle if they are already prominent in a song with a brighter mix or in case of poorly mastered tracks, making CE6 a more enthusiastic and aggressive listen than warm or neutral. With most songs, CE6 is highly addictive and makes you get lost in the music, which I think is the main USP of Craft Ears tuning having tried and reviewed the CE4 as well.
Overall, this character of the treble along with the Harman Target-ish signature enables instruments to have a very realistic and life-like presence in songs. If you like listening to orchestral tracks/scores or acoustic/pop-rock songs which have a more organic/live performance feel, it’ll make you hyper-aware, like you’re right there in the room with the musicians performing, even if you’re just an air-drummer. Some records like Foo Fighters’ ‘Sonic Highways’, Green Day’s ‘American Idiot’, John Mayer’s ‘Continuum’ and songs like Coldplay’s ‘Broken’ and even Twenty One Pilots’ ‘Hype’ sound extra special with CE6 and I don’t think I’ve enjoyed them this much on any other IEM recently.
Alright then, let’s dig in deeper…
Bass – Rasen Bass is not just a fancy marketing term, the bass really is very well tuned with good quantity and quality. It’s as if a dynamic driver and a balanced armature had a baby with good DNA traits of both parents. What really sets it apart are the dynamics, resolution and isolated separation bass has in all songs. It’s the kind of bass that stays in its place shining really well without ever coming in your face. It can play fast paced bass lines clearly and still rumble the deepest notes in the song precisely. Kicks have very good thump and impact as per the song’s mix, with very good isolated clarity without getting lost in a crowded mix.
Attack is on the neutral side, neither too sharp nor too smooth. It has very good low-end extension with more sub-bass than mid-bass like the Harman Target curve. Overall it is definitely north of neutral in its presentation but very well controlled and tuned, like a well calibrated sub-woofer attached to a reference studio monitor. It is technical but even more musical and fun with good slam and sub-bass rumble. It’s probably one of my favourite bass tuning I’ve ever heard in an IEM in this segment or probably ever!
Mids – Bass to upper midrange region flows amazingly and is very well-tuned, following the Harman Target curve quite closely and as a result, midrange has a nice neutral reference presentation. Lower mids are very clean, clear and detailed. They are more neutral and accurate tonality wise than full sounding. Upper mid-range is forward which gives good definition to instruments as well as vocals, making them very clear and well defined. Snares too have good body and crack. Overall, I personally find this presentation accurate, close to how flat frequency response studio monitors sound in a well-treated production room and not shouty at all but in general, like-ability depends on the set of IEMs one has been listening to and the kind of tuning one likes. All in all, midrange is very well layered and has very good clarity, resolution and detail retrieval.
Treble – CE6’s treble has a slight perceivable dip in the 4-7 kHz region which keeps the stick attack of drums in check, then a peak around 8kHz and a major one around 16kHz. The field-specific horn-loaded tweeter’s 16kHz upper treble peak is even more in amplitude than the ones in 64 Audio’s Tia Trio, A6t and U12t, which are already noticeably above neutral. It was a little polarising initially with some songs and I did need an adaptation period to get used to it but at the same time enabled CE6 to be highly resolving, lively and exciting. Once I had adapted, it was easier but still on the bright side. This is definitely not a laid-back relaxed presentation and in some songs it does highlight hi-hats/cymbals and vocal air/sizzle more than neutral but is mostly the case with brighter mixed tracks which have them extra-prominent or poorly mastered tracks in general. It sounds good with well mixed and mastered rock and metal records like Karnivool’s ‘Sound Awake’ and Periphery’s ‘Select Difficulty’ that have a lot of hi-hat and cymbal work, which sound exciting but not too intrusive. There is a quick solution for poorly mastered tracks which might tickle one’s sensitivity – just EQ 16kHz down by a couple of dBs (as per taste) and then bring it back up with other songs that it works well with. As you start EQ-ing the 16kHz down, the presentation starts getting closer to that of U12t’s. The songs with which the upper treble peak works well with, it enables them to have a very good clarity, air, openness and micro-detail retrieval.
Special mention – I heard Coldplay’s record ‘Everyday Life’ again with CE6, which is a more organic, live performance feel kind of album and I was impressed by CE6’s realistic, life-like and holographic presentation of the album. It kinda made me appreciate the album more than I did before, especially Guy Berryman’s bass tone and playing. Bass re-production had great rumble without any bloat like some IEMs had. Since this is a well mastered record with a slightly warmer sound, the only thing that jumped at me was the tambourine in the song ‘Arabesque’. Everything else sounded great as is but the bass and realism of instruments in the record had me engrossed deep. Frankly, CE6 has a talent of breathing new life into records and songs that you might have otherwise overlooked in the past.
Pairing with CE6’s flat impedance tech.
If you aren’t aware, high impedance sources can skew the sound signature of some sensitive IEMs and that can be a troublesome affair if you like plugging your IEMs into a variety of different sources. CE6’s flat impedance design keeps CE6’s sound signature unaffected from impedance differences between sources and really allows the true sound of the source to shine regardless of its impedance. IMO, it sounds best with neutral to slightly warmer sources and I especially loved its pairing with my UAD Apollo audio interface.
Soundstage and Imaging.
CE6 has a nice wide soundstage and its overall character allows for a very lively and holographic experience in most songs. Depth is very good too especially when a song has good depth mixed in it. It allows you to hear snare and vocal reverb trails fade into blackness very well in slower songs like Coldplay’s ‘Up in Flames’. The dip in lower treble in the 5-8kHz does affect the pin-point precise imaging and as a result you hear the songs like a wide soundscape as if you’re watching the band in a concert hall or an arena, which to be honest is very interesting though not the most technically accurate.
Note – Added U12t comparison on popular demand.
Craft Ears Four – Both CE4 and CE6 have Craft Ears DNA in their tuning with Harman Target inspiration and an upper treble lift. Overall, CE4 comes off warmer in comparison because CE6 has a bigger upper treble lift. CE6 has a little more sub-bass whereas CE4 has more mid-bass. Even though CE4’s bass presentation is quite enjoyable, CE6’s bass tuning is on another level with an even more exciting life-like quality and dynamics. Both have similar clean lower-midranges but CE4 has a slight dip in comparison and CE6 is more resolving, detailed and layered. Both have similar forward upper-midrange but I hear CE6 being a smidgen more forward, layered and has stronger instrument definition in comparison. Both have a dip in the 5-8kHz range but CE6 has more prominent 8kHz and 16kHz peaks and as a result sounds brighter as well as more exciting and fun. CE6 has better overall resolution, space between layers, imaging and micro-detail retrieval. Both have wide soundstages but CE6’s is more holographic; wider as well as deeper.
64 Audio U12t – Right off the bat, these two have a lot in common. Overall, both follow a similar tuning philosophy but loosely, U12t is a slightly warmer reference style IEM with a nice bass boost and smidgen lesser upper treble lift compared to CE6. U12t has more sub-bass as well as mid-bass quantity compared to CE6. U12t’s bass can sometimes seem more upfront than required in songs but generally occupies good defined space in the mix while keeping everything clean and controlled than bass-head levels of bass. It is highly enjoyable and fun as the bass character highlights excellent bass playing really well. CE6’s bass on the other hand is a bit more towards neutral relatively, slightly more technical but still a lot of fun. With CE6’s upper treble character’s support, bass sounds more life-like with better precision, quicker transients and a bit more dynamism and energy. CE6 has good quality rumble too but U12t sounds fuller with more weight but in the end doesn’t have the snappy precision that the CE6 has. Which bass one would enjoy more completely depends on one’s preference and liking. I personally like both for how well they work for their respective sound signatures and I keep swaying between them depending on the song’s mix but I’d probably choose CE6’s bass presentation more for my liking and preferences.
U12t has a warmer and slightly fuller lower-midrange relatively and as a result, instruments have a bit more body. CE6’s lower-midrange sounds slightly thinner in comparison. Both have a similar forward upper-midrange presentation with very good pinna gain and don’t sound shouty to me but U12t has smidgen less forwardness in the 3kHz area. They both have very good instrument tonality and timbre, where U12t sounds a bit more organic and natural, and CE6 sounds a little more lively and exciting.
U12t has more neutral and even sounding treble range. U12t and CE6 have a similar upper treble lift but U12t’s is slightly lesser in amplitude. As a result, CE6 sounds a little more aggressive relatively because of more prominent upper treble and lesser fullness in the lower midrange but in return also sounds more lively, spacious and clean with neutral to warm sounding mixes in comparison. U12t’s nice Tia driver upper treble peak is definitely prominent but is better balanced and also sounds a bit more forgiving of bad mixes and masters and as a result, helps U12t sound a little more versatile. But then, CE6 has a great talent of infusing the required liveliness and excitement in warmer songs which don’t sound as fun or in fact probably even boring with other IEMs.
Both have good wide holographic soundstages but U12t sounds slightly fuller and richer whereas CE6 sounds cleaner with more air between instruments. U12t has better imaging qualities. Both have very good detail retrieval where U12t does have the lead but not by much. Overall, both are high enjoyable for me personally but CE6 is a more energetic listen. U12t isn’t a relaxed listen by any means but is slightly warmer of the two and better balanced overall, especially in the treble region which also makes it a bit more versatile.
BGVP ES12 – ES12 too is a neutral sounding reference style monitor. I think I’d classify ES12 in the ‘true reference’ category whereas CE6 in the ‘live reference’ category. CE6 has slightly more sub-bass presence as it follows the Harman target style of bass presentation whereas ES12 has a more linear sub-bass and mid-bass relationship and sounds fuller as a result. Both are well done but CE6 sounds more lively whereas ES12 sounds like you’re listening to proper full range studio monitors. Both have very clean lower-midrange and forward upper-midrange but CE6 is slightly more forward in the upper-midrange in comparison. ES12 has a more even lower-treble presentation. Both CE6 and ES12 have a similar peak around 8kHz. Post that ES12 is smoother and more neutral in upper-treble presentation whereas CE6 is more boosted for an energetic listen. Both have good wide soundstages but CE6 is a little wider whereas ES12 is deeper. Both have very good detail retrieval but ES12 is a warmer and easier listen in comparison than CE6.
CustomArt Fibae7 – CustomArt too is based out of Poland (Warsaw). Fibae7 takes inspiration from Diffuse Field and Harman Target curves too and is very well tuned. CE6 has more sub-bass but Fibae7 has a bit more mid-bass. Both bass presentations are very well done as per their signatures where Fibae7’s bass presentation is more neutral and sounds like one’s listening to a record in a studio whereas CE6 has a more lively bass presentation. Both have very clean lower-midrange as well as a similarly forward upper-midrange presentation with Fibae7 being just a smidgen more forward. Fibae7 has a smoother treble presentation with it being more even in lower treble with a nice upper treble peak that is very close to neutral whereas CE6 is smooth in the 5-8kHz range but is more boosted in the 8-20kHz than neutral in comparison. As a result, Fibae7 comes off warmer whereas CE6 comes off more lively and energetic. CE6 is more open and airy sounding owing to its upper treble presentation. Both have very good wide soundstages but Fibae7 has deeper depth. CE6 brings out more details at the cost of coming off as bright whereas Fibae7 brings out similar details by staying smoother and neutral.
Lime Ears Aether R with ‘Switch ON’ – Lime Ears is also a Polish brand based out of Warsaw. CE6 has more sub-bass whereas Aether R has more mid-bass presence. Aether R’s lower mids sound slightly leaner and cleaner in comparison to CE6. Both have forward upper-midrange presentation but have peaks at slightly different frequencies with Aether R’s being around 2.5kHz and CE6’s being around 3.2kHz. Aether R has a dip in the 3.5-5kHz range whereas CE6 has it in the 5-8Khz range. Aether R is brighter in the lower treble because of a bigger peak around 8kHz whereas CE6 is brighter as well as more open and airy in the upper treble range. Both have wide soundstages but Aether R’s has it slight leaner and deeper.
Campfire Andromeda Pre-2020 – They both have a starkly different sound signatures as CE6 has a reference, neutral, cleaner and energetic presentation whereas Andromeda has a warmer and fuller presentation with lower treble sparkle. CE6 has more sub-bass whereas Andromeda has more midbass. Overall, CE6 has more realistic and tonally accurate bass whereas Andromeda has a fuller, more present bass presentation. Andromeda’s lower-midrange sounds much fuller whereas CE6’s lower-midrage sounds cleaner and has better resolution. CE6 upper-midrange is forwardly presented and tonally accurate whereas Andromeda’s upper-midrange sounds recessed in comparison. Andromeda has sparklier lower-treble whereas CE6 has a much more prominent upper-treble presentation. CE6 is more layered, resolving as well as open and airy sounding. Andromeda is no slouch but its presentation is targeted to be more fuller and fun than tonally accurate or reference. Both have wide soundstages but CE6 has better dynamics and a more realistic holographic soundstage.
ItsFit Fusion – Fusion has a DD for bass and has more sub-bass and mid-bass presence compared to CE6 but CE6 has more life-like, tonally accurate realism in bass whereas Fusion has a smoother attack but bigger impact. Fusion has fuller lower-midrange in comparison but CE6 has it cleaner and more layered. Fusion isn’t as forward sounding as CE6 but is still forward enough for good instrument and vocal definition. Fusion has a peak at 5kHz which enables more stick attack definition in drums but then both have dips in the 6-8kHz region. Fusion’s lower treble is similar to CE6 but it depends on the fit as Fusion’s treble is a little tip dependent. CE6 is more open and airy sounding but also brighter in upper treble compared to Fusion. CE6 has better micro-detail retrieval owing to its upper-treble character. Both have nice big soundstages but CE6 sounds a bit wider and deeper.
Craft Ears SIX is highly exciting and engaging with great bass, tonally accurate midrange and a treble presentation that presents songs with a lot of character, liveliness and realism but also makes for a more critical listen with some songs. It has very good resolution and micro-detail retrieval to satisfy most audiophiles that love to focus on the smallest nuances in songs and has a remarkable talent of breathing new life into records and songs that you might have otherwise overlooked in the past. With its build quality, life-like presentation of instruments and a comfortable deep insertion fit which isolates extremely well, it serves as a very good option for musicians looking for a high quality CIEM to use for live monitoring at this price point. All in all, this is definitely one of the landmark IEMs for me at the $1000 mark and one that I highly recommend you to check out, especially as a CIEM!
Gear used for testing and review.
- DAPs – iBasso DX160 | Hiby R6 Pro
- Laptop – Apple Macbook Pro 15″
- Audio Interfaces – Universal Audio Apollo | Focusrite Clarett 8PreX
- Phone – OnePlus 7 Pro
Reference Songs list.
- Foo Fighters – The Pretender, Best of you, Everlong & Sonic Highway album
- Coldplay – Paradise, Up in flames & Everglow + Everyday Life Album
- Biffy Clyro – A Celebration of Endings & Ellipsis albums
- Ed Sheeran – Thinking out loud, Bloodstream & Galway Girl
- Dave Matthews Band – Come Tomorrow album
- Dua Lipa – Future Nostalgia album
- Chainsmokers – Somebody, Sickboy, This Feeling & Closer
- John Mayer – Slow dancing in a burning room, Stop this Train, Say & A Face to Call Home
- Gavin James – Always & Hearts on fire
- Switchfoot – Meant to live & Dare you to move
- Porcupine Tree – Sound of Muzak, Blackest Eyes & .3
- Our Lady Peace – Do You Like It & Innocent
- Linkin Park – Papercut, Somewhere I belong & Talking to myself
- Maroon 5 – She will be loved, Payphone & Lost stars
- Lifehouse – All in all & Come back down
- Breaking Benjamin – Diary of Jane
- Karnivool – Simple boy & Goliath
- Dead Letter Circus – Real you
- I Am Giant – Purple heart, City limits & Transmission
- Muse – Panic station
- James Bay – Hold back the river