SeeAudio Yume IV

Mostly liked, variously described. Western reviewers and r/iems owners call it clean, balanced and neutral; Japanese reviewers more often call it warm, soft and mid-centric ('kamaboko'). The rigs explain both: bass is flat and the ear gain is low, so nothing is boosted except the vocal band and a treble peak. The dissent is that this reads as laid-back and unexciting (Gizaudio) or as an odd, vocal-only presentation (bisonicr, and an owner who later sold theirs).

“it's clean it's basically a straight line”

Jay Audio, YouTube

“全体的な音色として、私自身のイメージは「暖色寄り」だと感じました。”

Uni Sonia (“Overall, my impression of its tone is that it leans warm.”)

“nothing harsh but nothing stands out either so this is not my style to be honest”

Gizaudio, YouTube

The set's main strength for most sources: close, smooth, dense vocals, female vocals especially, with enough body for male voices and cleanly separated instruments. Japanese reviewers and owners rate it a standout for vocal and anime-song listening. Two dissenters hear it differently: Gizaudio finds the midrange recessed and laid-back, and one Japanese owner found voices so close that they sounded diffuse and unreal.

“Femail vocals are best part of mid-range.”

MD Rohit, Head-Fi

“ボーカルの距離は近めで、耳元で歌ってくれている様。”

イソシン, e☆イヤホン owner review (“Vocals sit close — like they're singing right by your ear.”)

“the mid-range here is a bit recessed a bit laidback and relaxed”

Gizaudio, YouTube

“声が近すぎて頭の中に響くような、もはや自分が声を発しているような感覚です。”

izumi, e☆イヤホン owner review, 3★ (“The voice is so close it echoes inside your head — it feels as if you're the one singing.”)

Sources split. Everyone agrees on the facts — tight, quick, mid-bass-led BA bass with little sub-bass rumble — and disagree on whether that is enough. One camp, mostly Japanese reviewers and owners, finds the punch surprisingly lively for two BAs and well judged for vocals. The other — Gizaudio, two Head-Fi reviewers and r/iems owners — hears the sub-bass as falling behind and the slam as close to absent. The measurements side with the second camp on quantity; the split is about taste.

Mostly praised as smooth, airy enough and free of sibilance — 'safe' to some, which is the point for treble-sensitive listeners. The dissent is about range rather than harshness: bisonicr hears the treble shaped around high vocal notes and other treble rendered inaccurately, el-snow hears a narrow frequency range, and one owner found it a little peaky on a piano-and-voice track.

“それでいて、サ行の刺さりが感じ易い楽曲で試しても刺激感は皆無。”

鴻池賢三, kakaku.com professional review (“Even on tracks prone to sibilance, there is no harshness at all.”)

“Yume 4 have a very well-controlled and smooth treble response.”

MD Rohit, Head-Fi

“逆に言うとそれ以外の高域はあまり正確に表現されません。”

bisonicr (“Put the other way, the rest of the treble isn't rendered very accurately.”)

Average at best. Head-Fi reviewers call it moderate or slightly better than average; Japanese reviewers call it narrow side to side, with some front-to-back depth, and say busy mixes make the narrowness obvious. Nobody calls it wide.

“Yume 4 have moderate soundstage, not too big or too wide, but well-balanced.”

MD Rohit, Head-Fi

“横の音場は狭く、上下の帯域レンジは狭めの前後に立体感のある音です。”

el-snow (“The stage is narrow side to side and the frequency range is narrowish, with depth front to back.”)

Generally good: precise placement and clean separation for a two-driver set, good enough that two reviewers recommend it for gaming. Images cluster toward the centre, and two Japanese listeners found the separation ordinary rather than a strength.

“The Imaging is distinctly precise.”

RK Turan, Head-Fi

“ただ全体的に解像度、分離が控えめで他の音に埋もれがちなのが残念。”

izumi, e☆イヤホン owner review, 3★ (“But resolution and separation are modest overall, so things tend to get buried.”)

Sources split evenly. One camp — a Japanese professional reviewer, two Head-Fi reviewers, Uni Sonia and most e☆イヤホン owners — hears clear, detailed vocals and good micro-detail. The other — Jay Audio, bisonicr, el-snow, Mitir, a self-paying Japanese blogger and two owners — finds resolution behind newer hybrids and planars at the price, most of all in dense, heavily layered tracks. The split tracks the music: praise comes on vocals and acoustic material, and the complaints on busy modern mixes.

The few sources who address it agree it is gentle rather than punchy: light slam, and loud passages that don't hit as hard as expected. Owners describe it as delicate, not dynamic.

“The words aggressive, dynamic, or thumpy do not belong in it’s vocabulary.”

Bobjonez98, r/iems (owner)

A strong point: small, light, smooth shells that several reviewers compare to a custom or semi-custom fit, comfortable for hours. The one recurring caveat is pressure — the shell is fully sealed with no vent, so some tips create a suction or pressure feeling, which four reviewers flag.

“小型軽量でフィット感は良好です。”

鴻池賢三, kakaku.com professional review (“Small and light, with a good fit.”)

“But since there is no proper ventilation, sometimes it create pressure inside the ear.”

MD Rohit, Head-Fi

“there is pressure built up with these because this is an unvented design”

Gizaudio, YouTube

Strong passive isolation from the sealed all-BA design — strong enough that one reviewer found it awkward for wearing outdoors. A Japanese professional reviewer rated it merely typical for an in-ear.

“Having only BA drivers meaning it doesn't have any vents, making it a beast in isolation.”

RK Turan, Head-Fi

The handmade, resin-filled shells are near-universally admired, and reviewers report no shell or nozzle problems. The complaints are around the edges. The stock cable is thin, light and 3.5 mm only. Several owners find the 2-pin socket so stiff and tight that pins slip or scrape on the way in, and one Japanese reviewer thinks the contacts hold the sound back. One video reviewer's unit arrived with a channel imbalance — all five measured units are within about 2 dB.

“The stock cable that come with this IEM is quite good in quality, but it feel very thin and look little cheap.”

MD Rohit, Head-Fi

“It slips because the connector protrudes a little in the recess so when trying to get the pins to line up the pins slip to the outside of the hole.”

calpis, r/iems (owner)

“mine also came with a channel imbalance but luckily I was able to fix it”

Jay Audio, YouTube

Sources split almost evenly, and the split tracks the price paid. At $199, Jay Audio calls it poor value for two BAs, Icy calls the MSRP too high, and a Japanese owner who sold theirs called it underwhelming for the money. A Japanese professional reviewer, Uni Sonia and most e☆イヤホン owners think the sound justifies it, and Uni Sonia ranks its vocals among the best in its price class. Both critics add that it makes sense on sale, and it has been listed for about $120.