Letshuoer Astralis

The clearest agreement. Ten rigs measure a big sub-bass shelf with real mid-bass behind it, and nearly every source praises its depth, speed and texture. The dissent is about amount, not quality: a few listeners find it bloated or masking, and one measurer calls it soft rather than tight.

“The low-end of the Letshuoer Astralis is very big and hard edged with a meaty and bullish presence and it is clearly the focus of this iem”

Chris Love, Mobileaudiophile

“These have planar bass like in spades.”

Zeos, in-Ear Fetish (YouTube)

“it feels bloated and constantly bleeds into the lower mids”

blay, Head-Fi (2.5★)

Sources split three ways. Most hear a warm, full-bodied midrange that flatters male voices; a sizeable group hears vocals — especially female ones — pushed behind the bass; a few hear the midrange as thin or boxy. The graphs explain the first two at once: the ear-gain peak arrives early and modestly, then the 2–6 kHz region sits well under target.

Sources split three ways. Most hear smooth, controlled, non-fatiguing treble with a little sparkle; some find it too safe and short of air; a smaller but loud group hears it as sharp, sibilant or metallic, and one owner returned it for sibilance. Two rigs show why the same set can sound so different: insertion depth moves the main treble peak by nearly an octave.

Sources split, though one camp is large. Most call it warm and bass-led — U- or L-shaped — and like it that way. A minority find the balance too dark and bass-heavy, and a smaller group hears it as cold or V-shaped instead. The measurements firmly support warm.

Sources split almost evenly. One side hears a wide, enveloping and sometimes holographic stage; the other calls it adequate, average for the class or, in one case, very narrow. A couple of reviewers say it opens up with a more powerful source.

Mostly praised for separation and steady placement, even by some of its critics. The reservations are that the big bass can mask some cues, and one Head-Fi reviewer rates imaging below average.

“The separation is one area of the technicalities in which Astralis excels.”

thaslaya

“This stage is very tall and has very good Z-axis depth too but the X-axis width is below par.”

Suman Sourav Meher, The Headphone List

“Imaging performance is below average”

Ryujinie, Head-Fi

Rated good for a warm set rather than class-leading: detail arrives smoothly instead of being pushed forward. The dissent comes from listeners who hear the bass masking the rest.

“The detail level is high, but i detail is conveyed in a smooth manner rather than in an articulate, forward way.”

Chris, The Headphoneer

“Superb resolution and detail, literally competing with IEMS twice the price”

Audiophile-Heaven

“While the S12 Pro is surgical and clean, the Astralis is muddy.”

blay, Head-Fi (2.5★)

A strength, especially in the bass, and several reviewers say it grows with more amplifier power. The reservation is that the relaxed upper midrange can make it feel less energetic than brighter planars.

“Highly dynamic with little compression”

Audiophile-Heaven

“Macro dynamics and overall energy can feel lacking compared to brighter planar sets”

Ryujinie, Head-Fi

Sources split along ear size. Most find the light aluminium shell compact, flush-fitting and comfortable for hours. A real minority find the large round shell presses on the ear: it failed one reviewer's small-ears test, and an owner returned it after an hour of aching.

Lightly covered, but positive: the sealed aluminium shell, with only small pressure-relief vents, blocks a useful amount of outside noise.

“around 20 dB to 25 dB of pure passive noise isolation”

Audiophile-Heaven

“Quite good isolation”

Pietro, Mobileaudiophile

Praised across the board, critics included: CNC aluminium shells, a modular 3.5/4.4 mm cable and a bundled USB-C dongle at $189. The gripes are small (the screw-top case, a cable one reviewer finds ordinary), but two owners have reported a channel fault within weeks — one driver crackling and quiet, the other fading in and out.

“Exceptional build quality in general”

Audiophile-Heaven

“Solid and comfortable shell design with a great aesthetic”

thaslaya

“I noticed the left driver started having a static sound and also a lower volume.”

u/UnshakenCore, r/iems

Sources split. Most call it one of the best warm planars under $200, especially with the cable and dongle in the box. Dissenters point to Letshuoer's own siblings — the S08 at about half the price, the S12 Ultra for a little less — as doing the same job as well or better.