By aspect — in detail
The defining trait and the most-argued axis: a very large, deep, sub-bass-led low end. One camp hears it as powerful, controlled and the highlight; another as overcooked — thick, and incoherent with the mids.
Measured
SoundGuys measured a large low-end lift — 'a huge bass lift of nearly 15dB' holding up to ~200 Hz; ASR notes extra energy below 70 Hz. A leaked squig.link graph put it 'midway between the RED and original Zero in ear gain tuning, with the most bass of the three.' The optional 5 Ω adapter adds a further ~5–6 dB bass shelf (corner near 360 Hz, per the hangout.audio 5128 graph).
⚠ vs. listeners — One measured bass shelf, two verdicts: bass-leaning and gaming listeners hear 'deep and controlled,' while neutral-leaning ears hear the same elevation as 'too much' that drowns the mids.
Where it splits
Deep, powerful, surprisingly controlled — the highlight.69%
“producing some of the best bass response I have heard in an IEM. It is deep, thundering and extended”
Audio Science Review (amirm)
Too much — thick and incoherent with the midrange.31%
“many of the hits in the bass just sound suffocatingly thick”
Headphones.com
Sources split: some hear the midrange as clear, natural and well-defined despite the bass; others as recessed, dry and lacking note-weight, pushed back behind the low end.
Measured
Tuned with Harman-style upper-mid (pinna) gain — a peak near 3.5 kHz brings vocals forward. ASR measured higher midrange distortion than other versions of this IEM.
Where it splits
Clear and natural despite the emphasized bass.44%
“The mid-range is surprisingly clear and well defined despite the emphasized mid-bass.”
iChos Reviews (Petros Laskis)
Recessed, dry and lacking note-weight.56%
“instruments and voices with significant midrange presence sound weirdly translucent and bereft of note weight”
Headphones.com
Broad agreement that it leans bright and energetic and can sharpen on vocal and cymbal peaks — and that it's strongly tip-dependent: the included foam tips tame the top, while the silicone tips push it up. One critic finds it a dealbreaker; most call it lively but a touch hot.
“The highs seemed glorious at first but then started to sound a bit bright.”
Audio Science Review (amirm)
“a noticeable sharpness and even a hint of brittleness in the upper treble that can become a bit fatiguing during longer sessions or when you bump up the volume”
PrimeAudio
“The treble perception depends on the ear-tips used, it is a bit smoother with the memory foam tips and will sound more prominent with the silicone.”
iChos Reviews (Petros Laskis)
Measured
ASR found a small excess of treble energy and EQ'd in a single corrective filter; SoundGuys' curve tracks their preference target until ~4 kHz. The included foam tips are part of the intended tuning (Crinacle recommends them).
⚠ vs. listeners — The treble lift is measurably real and tip-dependent; whether it reads as 'sparkle' or as 'glassy/piercing' is largely an ears-and-tips story rather than a disagreement about the graph.
Everyone agrees on the shape — a warm-tinted, bass-boosted V take on Harman 2019, the bassiest Zero yet. They split on the verdict: a polished, fun Harman done right, or an overcooked V-shape that isn't for accurate, critical listening (and 'yet another Harman variant').
Measured
Tuned to the Harman IE 2019 target with elevated bass; ASR's measured differential to target is 'very small' with silicone tips. It carries more bass and a more V-shaped tilt than the Zero:RED.
⚠ vs. listeners — 'Within target' vs 'too V-shaped' is the Harman-target debate itself: the graph sits near the curve most listeners prefer, but those who reject that target hear the result as overcooked rather than wrong.
Where it splits
A polished, near-target tuning done right.54%
“We are within measurement errors of our target and audience preference”
Audio Science Review (amirm)
Overcooked and bass-skewed — not for critical listening.46%
“presenting as more V-shaped than Harman to my ear, even with the foam tips”
Headphones.com
Sources split: most call it wide, spacious and great for positioning; a minority hears it as intimate, or as only 'artificially' spacious — a side effect of the gap in level between the big bass and the recessed mids.
Where it splits
Wide and spacious — strong for positioning.63%
“Excellent spatial width and depth allow for proper sound location.”
SoundGuys (Jhaycee Calvez)
Intimate, or only artificially staged.37%
“The soundstage is intimate without much width or depth but it images sufficiently well, at least with pieces that are not too demanding.”
iChos Reviews (Petros Laskis)
A genuine strength and the reason it's so often pitched at gamers — placement and directional cues are repeatedly praised. The main caveat is that imaging can read as narrow next to the wide stage.
“The positioning is outstanding. I had no trouble determining both the distance and direction of sounds.”
Head-Fi (iceberg)
“the slightly disorienting hallway-like depth and narrowness of imaging”
Headphones.com
Judged good for the ~$65 class — clean and clear — but not class-leading: a step below pricier sets, with resolution and texture refinement the recurring limit.
“The fidelity is stunningly good with a level of uncanny detail and broad spectrum cleanliness”
Audio Science Review (amirm)
“Clarity, separation and detail retrieval are good enough but the truth is that the Blue 2 is somewhat lacking in resolution and texture refinement.”
iChos Reviews (Petros Laskis)
Measured
Resolution is praised within its price class, not against pricier reference sets.
Sources split: most find the redesigned, lightweight (~4.5 g) shell and slimmer 6.2 mm nozzle much more comfortable than the original Zero; others find the nozzle still too long and chunky for their ears, or the cable hooks fatiguing past a couple of hours. It tracks ear shape.
Measured
Light ~4.5 g resin shells; the nozzle is narrowed to 6.2 mm (from the original Zero's 6.8 mm), with an adjusted angle — though it remains on the long side.
Where it splits
Much improved — light and comfortable for long sessions.62%
“This makes the shells much more comfortable for longer listening sessions.”
PrimeAudio
Still a long, chunky nozzle that doesn't suit every ear.38%
“this nozzle is still a bit on the chunky side, and still firmly on the long side.”
Headphones.com
Broadly liked: a nicely finished, glitter-blue medical-grade resin shell and a clearly upgraded cable over the original. Caveats are minor — a glossy faceplate that grabs fingerprints, the bulky look of the bass adapter, and the occasional QC/support complaint.
“an upgrade in its stock cable, which is now much thicker, smoother and less prone to tangling.”
PrimeAudio
“The ear-shells of the ZERO: Blue 2 are made from medical-grade resin material and are 3D printed by the renowned brand HeyGears”
iChos Reviews (Petros Laskis)
Measured
Medical-grade resin shells 3D-printed by HeyGears; an upgraded silver-plated OFC cable replaces the original's thin braided one.
Average for an IEM, and tip-dependent: the vented dual-DD shells let some sound in with silicone tips, while a deep fit and the foam tips improve it noticeably.
“The Zero Blue 2 blocks only about 40-50% of external noise.”
Head-Fi (iceberg)
“decent passive noise attenuation despite the three venting holes in each earpiece”
iChos Reviews (Petros Laskis)
Measured
Vented twin-DD shells; passive isolation is modest with silicone and improves with the foam tips.
Sources split: one camp calls it strong value — a fun, bass-rich, gaming-friendly set for ~$65 that ASR is 'happy to recommend'; another argues it's outclassed at the price by other Harman sets, including Truthear's own cheaper GATe, and is best only for a narrow use case.
Where it splits
Strong value — fun, and a gaming standout.54%
“I am happy to recommend the TRUTHEAR x Crinacle Zero:BLUE2. Another job well done.”
Audio Science Review (amirm)
Outclassed at the price — better Harman sets exist.46%
“a majority of people looking for a Harman-tuned IEM are going to be better served buying other Harman-tuned options in or below this price bracket”
Headphones.com
