For measurements, I am using the IEC 60318-4. I am posting raw measurements, which means I have not compensated them to any target. The curves are smoothed according to psychoacoustics in REW.
Please note that especially the high frequencies are inaccurate and/or difficult to read. I mark the coupler‘s resonance on the frequency response which might not be audible. Furthermore, tips and positioning can change the treble response significantly, more so with some IEM than with others.
Even without the issues described above, the in-ear coupler cannot replace or fully represent actual hearing impressions. There are several sonic factors that the frequency response does not show but that do translate to the quality of an IEM. Please be careful when trying to judge the quality of an in-ear system by the measurements alone.
I am not holding the frequency response against any target. Instead, I add a basic triangle which roughly shows where the frequencies should be amplified to be perceived as neutral or natural. If you compare the different available research on this topic, you will notice that all of them roughly follow the triangle in one way or another.
- 64 Audio A18t CIEM | warm monitor with a soft midrange and some added sparkle | ****°
- 64 Audio Fourté | fantastic bass, exciting treble, but a very unique midrange | ***°°
- 64 Audio Fourté Noir | minimal changes to the treble, Mundorf soldering is not enough of an upgrade | ***°°
- 64 Audio Nio (mX) | m20 | Apex mX modules recommended for a natural and soft sound | ****°
- 64 Audio Trió | arguably the better alternative to tia Fourté, but treble needs some tweaking | ****°
- 64 Audio U12t | 64’s best IEM, a bit bassy with a noticeably cut in the mid-treble transition, but overall great | *****
- 64 Audio U18s | very warm and bassy interpretation of a reference model, outmatched by older U18t | ***°°
- 64 Audio U18t | a bit too compressed sounding for a reference monitor, custom A18t is better | ****°
- Aful Performer 5 | fun and dynamic sounding, but smaller issues in the midrange | ***°°
- Astrotec AM850 | warm and bassy, bloat covers information in the midrange | **°°°
- AZLA Horizon | strong v-shape, carefully balanced, similar to A8000 | ***°°
- Beyerdynamic DTX 101 iE | typical consumer IEM, bassy, warm, not resolving | **°°°
- Beyerdynamic Xelento | not a high-end IEM, far too colored and fatiguing | **°°°
- Beyerdynamic Xelento 2nd Gen | big improvement over the original but very warm, dull mids | ***°°
- Binary Acoustics x Gizaudio Chopin | good mid-highs, but bass feels quite disconnected | ***°°
- Blon BL-03 | budget-fi wannabe MoonDrop Kanas with too much heft and sharpness | ***°°
- Blon BL-05 | very similar to BL-03, just nuanced changes that don’t improve treble enough | ***°°
- Brainwavz B100 | clouded and muddy, forgettable tuning | **°°°
- Brainwavz B400 | intimate and warm, not good use of driver count | **°°°
- Brainwavz M3 | relaxed-sounding budget IEM that lacks on both ends | **°°°
- Campfire Audio Andromeda | warm IEM with dull midrange, just not up to date anymore | ***°°
- Campfire Audio Andromeda S | nth revamp of the same design, no technical improvements | ***°°
- Campfire Audio Atlas | painfully exaggerated dynamic bass | *°°°°
- Campfire Audio Comet | decent approach to a balanced signature, but wonky tonality | ***°°
- Campfire Audio Solaris | probably Campfire’s best, yet recessed midrange and disappointing treble tuning | ****°
- Campfire Audio Vega | if you enjoy stupid amounts of bass, I can’t tell you if you’d prefer Atlas or Vega | *°°°°
- Cayin Fantasy | Final E | foam | violent upper mids and highs, useful to compensate for hearing loss | **°°°
- CCA C16 | budget-fi for fans of excessive w-signatures | **°°°
- Custom Art FIBAE 3 | CIEM | this is not a measurement error, though it looks like one | *°°°°
- DUNU EST 112 | balanced signature, deep bass, accurate mids, one of the better EST implementations | ****°
- DUNU Falcon Pro | transparency nozzle balances the musical bass nicely | ****°
- DUNU Luna | very mid-focussed tuning that excels with Rock music | ***°°
- DUNU Zen | Zen Pro | well-balanced tuning with good bass heft and forward mids, treble needs improving | ***°°
- Earsonics ES5 | very difficult tuning, makes any genre difficult to enjoy | *°°°°
- Etymotic ER3 XR | much-appreciated softness for the mid-forward ER tuning | ****°
- Etymotic ER4 PT | the original Etymotic was not off by much, but off enough to not matter anymore | ***°°
- Etymotic ER4 S | good base design troubled by anaemic bass and very forward mids | **°°°
- Final A8000 | excessive v-shape but excellent technicalities, can shine with a mod to improve midrange | ***°°
- Final B1 | fatiguing tuning, enjoyable only in short bursts and only if the music has soft treble | **°°°
- Final B2 | good body, a hint too much mids, severely lacking treble extension | **°°°
- Final B3 | v-shaped with too much focus on mid and upper bass | ***°°
- Final E1000 | well-balanced lo-fi budget solution, lacks the comfort of E2000 | ***°°
- Final E2000 | punchy bass and crunchy treble are fighting for your attention | ***°°
- Final E4000 | excellent for fans of warm tonalities, if only bass were less elevated | ****°
- Final E5000 | similar to E4000 but more expensive | ***°°
- Final F4100 | not really an alternative to ER4, has very specific use case for speech only | *°°°°
- Fischer Amps FA666 | foam | double-flange | decent warm IEM but drowns a lot of midrange resolution | ***°°
- Fischer Amps Rapture | very thick and dull-sounding midrange, though the highs are nice | **°°°
- Fostex TE-02 | good until 2kHz then falls apart | **°°°
- iBasso IT00 | quite okay if you want a warm-sounding IEM, nothing special | ***°°
- InEar ProMission X | hifi-tuned “upgrade” to PP8, but technically not really an improvement | ****°
- InEar ProPhile 8 (default) | I throned it best IEM for many years since 2017 and it’s still up there | ****°
- InEar ProPhile 8 VS | v-shaped version of PP8 (or switches on), decent bass but slightly sharp highs | ****°
- InEar StageDiver 2 | adequately natural and warm sounding, but lacking higher frequency information | ***°°
- InEar StageDiver 4 | really distant mids, artificial soundstage with awkward timbre | **°°°
- InEar StageDiver 5 | if you like the Andromeda, consider this one too, it’s the better w-shape | ***°°
- JVC/Drop HA-FXD1 | great bass, slightly bright midrange, treble doesn’t work for me | ***°°
- KBear KB06 | would do well with tamer bass, still lots of fine-tuning needed | **°°°
- KBear KB10 | sadly the tonality of the midrange is just awfully off and hollow sounding | **°°°
- KBear Neon | considering the tiny shell and single BA, this is a good effort | **°°°
- Kiwi Ears Quintet | one of the better Chi-Fi balanced signatures, but comes with expected fatigue | ****°
- Letshuoer S15 | warm and full sounding with good detail, but treble is more often miss than hit | ***°°
- MMR Homunculus | price and comfort aside, the tuning is actually ok | ***°°
- MMR Thummim | this cocktail of different drivers, phase issues and bad crossovers gives me a hangover | *°°°°
- MoonDrop Kanas Pro | biggest surprise of 2018, excellently tuned dynamic IEM | ****°
- MoonDrop S8 | very good neutral Harman-esque tuning, though slightly mid-focussed | ****°
- NF Audio NA1 | fairly decent for a single driver, but treble fatigue is very high | ***°°
- NF Audio NF6i | enjoyable bass, excellent highs, but suffers from a little dryness in the mids | ****°
- NiceHCK EP10 | suitable for Pop music, but sadly nothing else | **°°°
- Noble Audio Kaiser 10 | enjoyable sound thanks to w-signature, quite resolving but not true to source | ****°
- NuForce HEM4 | very congested sound, forward yet unexciting mids | *°°°°
- Oriolus MK2 | MK II or V2 has decent bass and mids, but treble can still be improved | ****°
- Oriveti Grand Supremacy | excellent warm and musical tribrid with a lush and soft midrange while preserving details | *****
- Oriveti OD200 | enjoyable and saturated tuning from a single DD (silver nozzle) | ***°°
- Oriveti OH300 | great value IEM for a dynamic and exciting w-shaped sound | ***°°
- Oriveti OH500 | enjoyable, natural and dynamic sound that cuts out any unwanted harshness | ****°
- Oriveti OH800 | the best Oriveti, non-hybrid design, lacks a hint of warmth | ****°
- qdc 4SS | forward bass, warm mids, best used on-stage or treble-sensitive users | ***°°
- qdc Gemini CIEM (default) | strong competitor to A12t, not as warm, but also not quite as refined | ****°
- Reecho x Peacock Spring | overall balanced, but it just never sounds right | **°°°
- RevoNext NEX202 | so much bass drowning everything, with small treble cues popping out in-between | *°°°°
- RevoNext NEX602 | what’s worse than the treble peak is its abundance of bass bloat | *°°°°
- rhines Stage 3 CIEM | at the time of UE and Westone, the Stage 3 was superior, but not anymore | ***°°
- Shure SE215 | for its age the mids are quite impressive and the strong bass suits an active lifestyle | ***°°
- Softears Cerberus | another take on tribrid designs with DD+BA+EST, sadly flawed by a deep 6kHz-cut | ***°°
- Softears Enigma | the warm high-end tribrid that Cerberus wants to be | *****
- Softears RS10 | technical marvel, very neutral and transparent tuning like near-fields, just a hint bright | *****
- Softears RS10 CIEM | at point of review, by far the most refined IEM I have ever experienced | *****
- Softears RSV | SpinFit | colourless, lets the music talk by itself, especially with SpinFit ear tips | *****
- Softears Studio 4 | dampened version of the RSV without a more papery timbre | ***°°
- Softears Turii | one of the best single-DD IEM, added musicality and excitement on top of neutral clarity | *****
- Sony MH1 | The MH1 and MH1C were from the future, but the terrible cable ruined the experience | ***°°
- SoundMAGIC E11BT | ok budget solution if you need wireless with neckband | **°°°
- ThieAudio Clairvoyance | strong sub-bass and highs, works well as a hifi-tuning | ****°
- ThieAudio Monarch | refined for what it is, but ultimately disjointed with excessive lows and shouty mids | ***°°
- TRI Audio i4 | ok-ish Budget-Fi with still a lot of room for improvement | **°°°
- Ultimate Ears Reference Remastered | the UERR is not much of a reference except for Westone | ***°°
- Westone W40 | terribly outdated design, sound challenged by the comfortable but tiny shell | **°°°
- Westone W60 | minimally improved over W40 but ultimately useless tuning | **°°°
- Westone W80 | unless you have special hearing, you should not consider this IEM | *°°°°
- Bonus: My Personal Optimal Frequency Response
