By aspect — in detail
The defining argument, and the reason this set's scores scatter from 2/10 to 8/10. One camp reports a strong, fatiguing upper emphasis — sibilance, splashy cymbals, listening sessions cut short — and reaches for EQ. The other hears an accurate, unproblematic top end and leaves it alone. Crucially the two camps are not describing the same octave: the 'harsh' reports track a large, late ear-gain peak around 3.5–4.3 kHz, while the 'muted' and 'laid-back' reports track the dip above 5 kHz, and the loudest complaints of all point at a 12–13 kHz peak that measurement rigs cannot agree exists.
Measured
Four independent squig.link rigs (Super* Review, Paul Wasabii, Precogvision, nymz), normalized to 1 kHz, agree closely through the lower treble: an ear-gain peak of +8.3 to +9.1 dB placed unusually late at 3.35–3.82 kHz, a dip at 6.3–6.6 kHz (+2.6 to +5.2 dB), and a peak at 7.9–8.0 kHz sitting 2.7–4.4 dB above it. SoundGuys reaches the same conclusion from its own rig and prescribes -7 dB at 4,264 Hz with +2.4 dB at 5,957 Hz and +1.9 dB at 7,022 Hz — an EQ that inverts the measured shape almost exactly. Above 10 kHz the agreement collapses: at 13 kHz the four rigs read +5.6, -6.7, +6.9 and +1.8 dB (a 13.6 dB spread) and at 14 kHz +0.3, -10.4, +1.0 and -1.0 dB.
⚠ vs. listeners — The dispute is partly unresolvable by measurement, and everyone measuring says so. amirm found a peak near 12.7 kHz and declined to trust it because the fixture is not accurate there; Headphonesty annotates its own graph that the 8 kHz peak is a coupler artefact and that everything above 10 kHz is unreliable; and the four rigs bear that out by disagreeing 13.6 dB at 13 kHz while agreeing inside a decibel at 3.5 kHz. So the harshness reports that cite a 12–13 kHz spike sit in a band no coupler pins down, while the part every rig DOES agree on — a big, late ear-gain peak — is the likeliest physical cause of the fatigue.
Where it splits
Too hot and fatiguing — a strong lower-treble/presence emphasis that turns sibilant and splashy, and is best EQ'd down.45%
“they have a rather strong emphasis in the highs, followed by a comparatively low emphasis past 5kHz”
SoundGuys
Well-judged and essentially accurate — extended without being a problem; nothing here that wants fixing.55%
“I could see someone liking it better that way but I liked it without.”
Audio Science Review (amirm)
Mids
Strong consensus · 9 srcThe one point of strong agreement and the set's clearest strength. Reviewers across every camp — including those who dislike it overall — describe a transparent, uncoloured midrange with clear, forward vocals and no bass encroachment. IEMRanking's twelve-reviewer average makes mids the highest-graded aspect on the sheet, and the critical sources concede it too.
“The midrange of the Zero is tuned to be very transparent and clear”
Headphonesty
“Vocals are placed up front and rise clearly above everything else.”
Prime Audio
Measured
The lower midrange sits slightly below the 1 kHz reference on every rig (-0.7 to -1.5 dB at 500 Hz), which is what produces the widely-reported lean note weight, while the +8.3 to +9.1 dB ear gain at 3.35–3.82 kHz pushes vocal presence forward. Headphonesty reads about 7 dB of pinna gain from its own coupler and calls the upper mids only slightly boosted — the same feature the brightness camp blames for shout.
Everyone describes the same low end and then disagrees about whether it is enough. The shape is not in dispute: a narrow sub-bass shelf with almost no mid-bass lift, so the bass is fast and completely uncoloured but modest in quantity and short on punch. One camp treats that as a virtue — clean, textured, no bleed into the mids — while the other calls it thin and says bassheads should look elsewhere. Tip choice moves it: several reviewers note that dense foams or a deeper seal noticeably fill in the low end.
Measured
All four rigs agree tightly on the shape: +6.0 to +7.4 dB at 20 Hz, already down to +1.7 to +3.4 dB by 100 Hz and back to level by 200 Hz (-0.3 to +1.5 dB). That is a sub-bass-only shelf with essentially zero mid-bass elevation, which is exactly why the same set reads as 'clean and fast' and 'has no punch' to different listeners. amirm measured distortion as impressively low apart from a small resonance near 1 kHz, so the low end stays clean at volume rather than being limited by the driver.
Where it splits
Too light — subdued, below neutral in quantity, and lacking weight and slam.37%
“Bass is subdued and it is below what I would call neutral”
Soundphile Review
Ample and unusually clean — real sub-bass extension with quality that outclasses the price.63%
“Sub-bass reproduction was excellent for an IEM and overall fidelity beyond belief at times.”
Audio Science Review (amirm)
Tonality
Contested · 9 srcSources cannot even agree on the label. It is variously called neutral, neutral-bright, balanced, mildly V-shaped and — by IEMRanking's classification — V-shaped outright. The measurement camp reads it as close to a sensible target; the critical camp reads the same curve as lean, sterile and not neutral at all. What is not in dispute is that it is a deliberately un-warm, clarity-first voicing, which was itself unusual in a bracket then dominated by Harman-ish and V-shaped budget sets.
Measured
The disagreement is a normalization argument. Referenced to 1 kHz the curve looks tidy, but SoundGuys notes that normalizing bass and mids to its target instead makes the ~3 kHz bump exceed the target by a significant margin. Both readings describe the same physical response: a modest sub-bass shelf, slightly recessed lower mids, and a large late ear-gain peak. Specs are 32 Ω and 108 dB/V over 10 Hz–20 kHz, and amirm found impedance flat and low.
Where it splits
Accurate and well-judged — close enough to a proper target that it needs no apology.55%
“It took all of 2 seconds to realize this is the same accurate, neutral response I like to hear.”
Audio Science Review (amirm)
Not actually neutral — lean, thin-noted and treble-tilted, closer to a V than to a reference line.45%
“Are the 7Hz Salnotes Zero neutral? No.”
SoundGuys
Rated respectable for the money and no more. The recurring verdict is that the clarity is real but partly a by-product of the lean, treble-forward voicing rather than genuine resolution, and that separation gets fuzzy when the mix gets busy. IEMRanking's twelve-reviewer technical grade is the weakest column on its sheet, and RedditRecs' single recurring criticism is exactly this. A minority — including amirm — rate it well beyond its price.
“Imaging, micro-details, and instrument separation are fuzzy at times, though clarity is exemplary”
Headphonesty
“the overall sound seems a little veiled in terms of technicalities and left me craving for a bit more detail”
Perrivan Audio
A real split, and unusually it comes with a head-to-head contradiction on the same use case. Several reviewers and the Reddit aggregate single out placement and separation as a strength, with gaming called out as a specific win. Against that, SoundGuys' virtual-panel scoring makes immersiveness the set's weakest dimension and explicitly warns off first-person shooters, and Headphonesty and the IEMRanking average both grade imaging below the middle.
Measured
SoundGuys' MDAQS run (HEAD acoustics' virtual listener panel) scores timbre excellent and distortion very good but immersiveness mediocre, dragging the overall to 4.5 — an objective correlate of the split, since the same panel that rewards the tonality marks down the space.
Where it splits
Precise and well-separated for the money — spatially convincing beyond the price, and a budget gaming pick.62%
“I was at times surprised by the good externalization/spatial effects of this IEM.”
Audio Science Review (amirm)
Flat and imprecise — placement blurs, and positional cues are unreliable.38%
“Given that the immersiveness score is so low, you may find that sounds are hard to place around you in first-person shooters.”
SoundGuys
Soundstage
Moderate · 8 srcThe most consistent reading of any contested-adjacent aspect: average size, no more. Reviewers converge on a stage that is neither congested nor notably expansive, with a roughly even balance of width and depth. The dissent is mild in both directions — a few find it surprisingly open for $20, a few find it flat — and it is generally treated as the expected limit of the class rather than a fault.
“The soundstage is bang average in all three directions.”
Headphonesty
“Zero's soundstage is modest in dimensions with an almost even mix of width and depth.”
Prime Audio
Dynamics
Contested · 5 srcSplit along the same line as the bass. Because the low end carries no mid-bass lift and the note weight is lean, one group hears the presentation as compressed and short on contrast, while another hears the speed that same tuning buys — fast transients and tight, well-controlled attack. There is no real dispute about the underlying character, only about whether 'quick and lean' reads as dynamic or as flat.
Where it splits
Compressed and lean — blunted contrast and thin note weight rather than real slam.42%
“Dynamics sound noticeably compressed, muting contrast between quiet and loud. Transients feel blunted and slow.”
IEMRanking (12-reviewer average)
Fast and tidy — quick, well-controlled transients that suit the clean tuning.58%
“transients are fast and well-portrayed”
Soundphile Review
Mostly good, with a real minority report. The shells are small and very light, and the majority — including reviewers who dislike the sound — find them easy to forget. The dissent is structural rather than a matter of taste: the shell is squarish with prominent angled edges, and the nozzle is on the long side, so a minority report hotspots on longer sessions or an outright poor fit. Tip choice matters more than usual here.
Where it splits
Light and comfortable — small shells that disappear in the ear for long sessions.72%
“the fit was excellent and with their light weight, I could barely feel them”
Audio Science Review (amirm)
Angular shell causes trouble — edges and nozzle length produce discomfort over time for some ears.28%
“The shells are relatively light, though I experience slight discomfort with prolonged usage.”
Headphonesty
Isolation
Contested · 3 srcGenuinely unsettled, and the sources contradict each other flatly rather than by degree. The design is vented, and the one objective measurement puts attenuation in the ordinary range for a sealed IEM — decent for commuting but no more. Written impressions run from 'above average' to 'almost absent,' which is a larger gap than tuning taste explains and most likely reflects how well each reviewer sealed with the stock tips.
Measured
SoundGuys measures an average loudness reduction of 61.1%, with the blocked energy overwhelmingly above 1 kHz — i.e. ordinary passive attenuation that does little for low rumble — and stresses that it depends heavily on achieving a good seal.
Where it splits
Decent — enough attenuation for everyday and commuting use.67%
“you can expect outside junk sound to be reduced by 61.1% in loudness”
SoundGuys
Poor — barely blocks anything, and unsuited to noisy environments.33%
“Passive isolation is almost absent”
Soundphile Review
The one aspect where the critical side carries slightly more weight. Everyone agrees the headline feature was remarkable for 2022 and the price: a detachable 0.78 mm 2-pin cable when rivals were still hard-wiring theirs. Opinions on the execution diverge — some find the shell solid and well-finished for $20, while others report cheap-feeling plastic, poor stock tips and cable, barely legible channel markings, and at least one unit whose faceplate worked loose.
Where it splits
Cheap-feeling and inconsistent — thin plastic, weak accessories, and some units with real assembly faults.54%
“The molded plastic looks cheep and the left and right markings barely visible.”
Audio Science Review (amirm)
Solid for the money — a sturdy shell with a metal faceplate, and a detachable cable that rivals didn't offer.46%
“For 20 bucks, the shells are quite well-built”
Headphonesty
The nearest thing to consensus, and the reason the set matters. At roughly $20 with a detachable cable, it was treated on release as a category reset and a default first recommendation, and the measurement-led reviews still rate it a bargain. The honest counterweight is that its own success dated it: the ranking-list aggregate normalizes twelve expert reviews to a middling score, Reddit sentiment now places it well down the budget field, and the cheaper, better-rounded sets it inspired have largely replaced it — including at 7Hz, whose own Zero:2 superseded it.
“So much fidelity for so little money!”
Audio Science Review (amirm)
“It hits well above it's bargain price point, and then some.”
Antdroid, Audio Discourse
Measured
Roughly $20 street against a $22.99 MSRP; RedditRecs tracks $22 at Amazon and $18 at Linsoul, though every variant on Linsoul's own store now reads out of stock. The aggregates disagree as sharply as the reviewers: ASR's thread poll runs 81.9% 'Great' across 277 voters, while IEMRanking normalizes 12 expert reviews to 5.5/10 ('B Tier | Mixed') with a raw reviewer average of 4.9 and individual scores from 2.0 to 8.0, and RedditRecs reads 66% positive across 136 Reddit reviews at #79 in IEMs.
