In-Ear MonitorOverreview

7Hz x Crinacle Zero:2

The $25 sequel that swapped the original Zero's sparkle for slam — a near-consensus budget champ whose one real argument is whether the smoother treble is a comfort win or a step too dark.

14 sourcesUpdated
$20Typical US price

Score aggregates reviewer opinions across topics.

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7Hz x Crinacle Zero:2

The short version

What to know.

The 7Hz x Crinacle Zero:2 is a ~$25 single-dynamic-driver IEM and the Crinacle-tuned sequel to the 7Hz Salnotes Zero, re-voiced warmer and bassier with a smoother treble. Reviewers broadly agree on the core: a warm-neutral, lightly V-/W-shaped tuning with clearly enhanced sub- and mid-bass, clean and natural mids, a smooth non-fatiguing top, cohesive imaging, an average-but-good-for-price soundstage (more depth than width), a feather-light comfortable shell, and objectively excellent engineering — measurements show unusually low distortion and an easy-to-drive load. It is also, near-universally, treated as outstanding value and a safe budget default. The genuine disagreement is the treble: everyone hears/measures the same smoother, less-airy top (a real dip through 4-8 kHz versus the original), but one camp calls that a fatigue-free comfort win while a measurement-backed camp calls it too recessed/dark and prefers a little EQ. Secondary fault lines: whether the extra bass is 'perfectly judged' or 'polarizing' (some hear a touch of mid-bass bloat, a lone reviewer finds it bass-light, and the slam is fit-dependent); whether the Zero:2 is even an upgrade over the cleaner, airier original Zero; and the recurring gripes about a cheap cable, no case, and some reports of a channel failing. Resolution is agreed to be only 'average' — the tuning-first limiter — and the toy-ish looks are a matter of taste.

About this product

The ~$25 Zero:2 (a.k.a. 7Hz Salnotes Zero 2) is a single 10 mm dual-cavity dynamic-driver IEM in a translucent acrylic shell with an aluminium faceplate — the 2023 sequel to the 2022 7Hz Salnotes Zero, again voiced with reviewer Crinacle, now with roughly +3 dB more low-end and a smoother, less-peaky treble via a new PU+Metal composite driver and cable. 32 Ω, 108 dB/V, 10 Hz-20 kHz, 0.78 mm 2-pin, ~4 g/side, in Silver/clear, Orange and Blue. Not the original 7Hz Salnotes Zero (the 'Zero 1'), and not the Truthear-made x Crinacle Zero / Zero:RED / Zero:BLUE(2), which are separate dual-DD collaborations.

The 7Hz x Crinacle Zero:2 is the 2023 follow-up to the 7Hz Salnotes Zero, the roughly $20 single-dynamic IEM that became the default 'first real IEM' recommendation on the strength of a near-reference tuning. For the sequel, 7Hz and reviewer Crinacle kept the shape and the price but added a new 10 mm driver, an upgraded cable, translucent shells — and, most audibly, about 3 dB more bass with a smoother top end.

That makes the Zero:2 less a revolution than a re-flavouring of a proven recipe, and it landed as one of the most-recommended ultra-budget sets on the market — #1 in IEMs by Reddit sentiment and a 4.2/5 across thousands of owner ratings. It also split the enthusiast crowd in a very specific way: almost everyone agrees it's excellent value and easy to live with, while the measurement-minded argue about the treble and the die-hards argue about whether it's actually an upgrade over the original at all.

A good fit for

  • First-time IEM buyers wanting a safe, well-tuned, easy-to-drive set for ~$25
  • Listeners who want a warm, fun, bass-forward signature that stays smooth and non-fatiguing
  • People who found the original Zero too lean or too bright in the treble
  • Casual listening, commuting and budget gaming (cohesive imaging, good isolation with a seal)
  • Anyone happy to EQ — measurements show it responds superbly to a small treble lift

Think twice if

  • You chase air, sparkle and treble extension out of the box — the top is deliberately rolled back
  • You want maximum resolution and micro-detail; this is a tuning-first set with only average technicalities
  • You already own the original Zero (or a similar budget set) and want a real step up, not a re-flavour — look higher (e.g. Simgot EW200)
  • You need premium accessories or a rugged cable and case in the box
  • Your ears need a deep insertion to seal — the short nozzles fit shallow

The reviewer consensus

Agreement &
disagreement.

1 / 12topics divide opinion
valuebasstonalitymidssoundstageimagingdetaildynamicscomfortbuildisolationtreble
1 Strong agreement10 Mostly agree1 Divided opinions

Common ground6

  • A warm-neutral, bass-boosted re-tune of the original Zero — variously called mild V/W, U-shaped or 'Harman with more bass,' but fun-leaning and consumer-friendly.
  • Clearly enhanced sub- and mid-bass with real rumble and punch from the new 10 mm driver — the headline upgrade and the highlight for most.
  • A smooth, non-fatiguing top end that removes the original's harsh upper-treble peak (at the cost of some air).

Points of contention5

  • Treble: 'smooth and non-fatiguing, the OG's peak fixed' vs 'too recessed/dark, ~5 dB short and better EQ'd' — the split tracks how measurement-minded the listener is.
  • Is it even an upgrade over the original Zero? Several reviewers prefer the OG's cleaner, airier, more open balance and treat the Zero:2 as a different flavour, not a better one.
  • Bass: 'perfectly judged and satisfying' vs 'polarizing' — a few hear mild mid-bass bloat, a basshead finds it too tame, and one reviewer even calls it bass-light; perceived quantity is strongly fit-dependent.

A closer listen.

12 topics · 1 divided
Left: criticalRight: positiveTighter lines: more agreement

Treble

Leans positiveDivided opinions
Reviewer sentiment13 supporting sources
CriticalNeutralPositive

Band: opinion spread · Dot: weighted average

The one genuinely contested axis. The measured facts are agreed: versus the original Zero the Zero:2 tames the old upper-treble peak and drops presence through roughly 4-8 kHz, so it's smoother, safer and less airy. Where reviewers split is on the verdict. One camp — most editorial reviewers and comfort-first listeners — calls it non-fatiguing and ear-friendly, a clear improvement on the OG's occasional harshness. A measurement-backed camp calls it too recessed/dark, short on sparkle, and best restored with a touch of EQ. A lone outlier (Headphonesty) still finds it can get shouty on busy tracks.

Measured

Both a GRAS 45CA (ASR) and a B&K 5128 (Resolve) read the same tilt: the original Zero's upper-treble peak is removed and there's a real dip through the 4-8 kHz region — amirm quantifies it as a '5+ dB' treble shortfall; Acho Reviews' squig.link work calls the 5-6 kHz dip 'a little too pronounced.' Upper-treble air rolls off, so sparkle is reduced. amirm's AB tests preferred a treble-lifting EQ.

vs. listeners — Same measured smoothing, opposite verdicts: what one camp hears as 'safe and non-fatiguing' the other measures as a 5 dB shortfall and hears as 'recessed/dark.' The two heaviest measurement sources land on the critical side — amirm preferred EQ, and Resolve's ranking-list note is bluntly 'Treble is still a problem' — while most subjective reviewers count the calmer top as an upgrade.

Where it splits
Smooth, laid-back and non-fatiguing — the OG Zero's harsh peak is gone; a comfort win that keeps enough clarity.55%

“This results in a more laid-back treble, stepping back from the limelight while still unravelling sufficient details.”

Prime Audio
Too recessed/dark and short on air — a real ~5 dB treble shortfall that measurement-minded listeners prefer to EQ back.45%

“the highs were a little recessed and at times I was hearing bass I didn't even know was there!”

Audio Science Review (amirm)
Link to this topic

The hardware

Specifications.

Checked

Design

Type
In-ear monitor
Drivers
1 × 10 mm dynamic (dual-cavity, PU+Metal composite diaphragm)

Electrical

Impedance
32 Ω
Sensitivity
108 dB/V≈ 93.1 dB/mW
Frequency response
10 Hz – 20 kHz

Connection

Cable
Detachable
Connector
0.78 mm 2-pin

Manufacturer-published figures, not measurements · from linsoul.com, thehificat.com.

Follow the evidence

Sources 14

1–6 of 14 sources

Read with context

Limitations & method.

As of

What to keep in mind 5

  1. This is a read of where the reviews land as of mid-2026, in an ultra-budget IEM bracket that moves fast — cross-shops like the original 7Hz Zero, Moondrop Chu 2, Tanchjim One, Simgot EW200, Truthear Hexa and Blon Z300 come up constantly.

  2. Opinions here are unusually taste-driven: the same smoother, bassier tuning that most call a comfort win is what treble-focused and measurement-minded listeners mark down, so the published expert scores genuinely scatter (roughly 3.6 to 8.3 out of 10). Read which camp a reviewer sits in, not just the number.

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