7Hz Zero 2 is the better buy for most people. It improves on the original with more sub-bass, a smoother treble, and an upgraded cable — all for roughly $5 more. If you specifically want a Harman-neutral reference sound or sharper treble detail, the original Zero remains a strong choice at ~$20.
Quick Verdict
The 7Hz Zero and Zero 2 are both exceptional budget IEMs under $25, but they serve slightly different listener profiles. The Zero 2 wins for most casual listeners: it has more bass impact, a more relaxed treble, and a better stock cable. The original Zero edges ahead for neutral-reference seekers and FPS gamers who value detail and imaging over warmth.
Buy the 7Hz Zero if: you want a Harman-aligned, detail-focused sound signature.
Buy the 7Hz Zero 2 if: you prefer a warmer, bassier, fatigue-free listening experience.
What Is the 7Hz Zero?
The 7Hz Zero — also sold under the Salnotes sub-brand — is a budget single dynamic driver IEM released in 2022 by Chinese audio manufacturer 7Hz. Priced at approximately $20, it uses a 10mm dynamic driver and was tuned to closely follow the Harman target curve. It became a widely recommended entry-level IEM in the ChiFi audiophile community, praised for its neutral, detail-oriented sound at an aggressive price point.
What Is the 7Hz Zero 2?
The 7Hz Zero 2 (also written Zero:2) is the 2023 successor to the original Zero, developed in collaboration with Crinacle — the founder of In-Ear Fidelity and one of the most influential IEM reviewers and measurement experts in the hobby. Priced at approximately $25, the Zero 2 features an upgraded 10mm dual-cavity dynamic driver with a PU+Metal composite diaphragm, a silver-plated OFC coaxial cable, and a retuned sound signature with roughly 3dB more low-end gain compared to its predecessor.
7Hz Zero vs 7Hz Zero 2: Detailed Comparison
Here is how the two IEMs compare across every meaningful dimension a buyer should consider:
Driver Technology
- 7Hz Zero: Standard 10mm dynamic driver
- 7Hz Zero 2: 10mm dual-cavity dynamic driver with PU+Metal composite diaphragm — designed for faster diaphragm movement and reduced distortion
Sound Signature
- 7Hz Zero: Harman-neutral leaning, tighter bass, slightly elevated treble, more analytical
- 7Hz Zero 2: Warmer, mild V-shape, more sub-bass extension, smoother and more laid-back treble
Cable Quality
- 7Hz Zero: Standard OFC cable
- 7Hz Zero 2: Silver-plated OFC coaxial cable — a meaningful upgrade in signal transmission and durability feel
Connector
- Both: 0.78mm 2-pin detachable connector — fully compatible with the same aftermarket cable ecosystem
Frequency Response
- 7Hz Zero: 20Hz–20kHz
- 7Hz Zero 2: 10Hz–20kHz — slightly better specified sub-bass extension on paper
Impedance and Sensitivity
- Both: 32 ohms impedance, 108dB sensitivity — neither requires a dedicated amplifier and both drive easily from a smartphone or basic USB dongle
Price
- 7Hz Zero: ~$20
- 7Hz Zero 2: ~$25
Build and Colorways
- Both use an acrylic shell with a metal faceplate and the same overall ergonomic shape. The Zero 2 is available in multiple color variants including silver, orange, and blue.
The most important difference between these two IEMs is the tuning philosophy. The original Zero was designed with close adherence to the Harman target — an industry-standard frequency response curve widely regarded as the most preferred sound signature across large listener panels. This gives the Zero a relatively flat, reference-adjacent character with a modest bass shelf, neutral mids, and a slightly elevated treble that enhances the perception of detail. For listeners coming from studio monitors or flat-reference headphones, the Zero feels familiar and accurate.
The Zero 2 departs from this slightly in a direction most casual consumers will prefer. The additional 3dB of low-end gain — most notable in the sub-bass and midbass regions — gives music more physical weight and impact without tipping into bass-head territory. Crinacle’s involvement through In-Ear Fidelity means the tuning is deliberate and measurement-verified rather than accidental. The result is a signature that sits between the original Zero’s neutrality and a consumer-friendly warm-neutral profile.
The treble difference is also meaningful. The Zero’s slightly hotter top end contributes to its detail perception but also introduces more sibilance risk on poorly mastered recordings and can cause listening fatigue during extended sessions. The Zero 2’s smoother, more rolled-off treble trades a small amount of perceived sparkle for a significantly more forgiving and enjoyable long-session experience. Neither IEM is harsh by budget IEM standards, but the Zero 2 is the safer choice for treble-sensitive listeners.
One durability concern worth noting directly: across multiple Reddit threads and Head-Fi community reports, some Zero 2 users have documented right-earbud pin connector failures — typically presenting as channel imbalance or complete dropout in one ear. This appears linked to the 0.78mm 2-pin connection on the right shell. If you receive a Zero 2 and notice channel imbalance out of the box, reseat the cable connectors firmly before assuming a driver fault. This is not a universal failure, but it is documented enough to be worth knowing before purchase.
Sound Quality: Bass, Mids, Treble, and Technical Performance
Bass
The Zero 2 wins here if bass matters to you. The dual-cavity driver design and +3dB low-end tuning give it noticeably more sub-bass rumble and mid-bass punch than the original Zero. Electronic music, hip-hop, and pop all benefit from this added weight. The original Zero’s bass is tighter, faster, and more controlled — closer to what a neutral reference monitor would produce. Neither IEM has bloated or muddy low end, but the Zero has cleaner bass texture and better definition at the cost of physical impact.
Midrange
Both IEMs handle vocals competently at their price tier. The Zero’s midrange is cleaner and more forward, making it the better choice for acoustic music and vocal-centric genres where clarity and separation matter. Female vocals in particular have better presence and articulation on the Zero. The Zero 2 adds more body and warmth to the midrange, which some listeners will find more natural and organic — male vocals especially benefit from the added resonance — but it is slightly more recessed relative to the bass compared to the original.
Treble
The Zero has a mild treble lift that increases perceived detail and air in the upper frequencies. This helps it sound more resolving on complex tracks but does introduce some sibilance risk on recordings with hot high frequencies. The Zero 2 smooths this region out significantly — it is one of the more fatigue-free budget IEMs available, making it well-suited for long commutes, work sessions, or marathon listening. If you are treble-sensitive or find many budget IEMs harsh, the Zero 2 is the safer choice.
Soundstage, Imaging, and Technical Performance
Both IEMs perform respectably for their price tier — well above what most people expect from sub-$30 audio. The Zero has a slight edge in perceived instrument separation and imaging precision, partly a function of its more forward midrange and elevated treble giving each element in a mix more defined space. The Zero 2’s warmer tuning softens boundaries slightly, making it sound more cohesive but marginally less analytical. For FPS gaming where positional audio accuracy matters, the Zero is the stronger pick. For relaxed music listening where presentation matters more than dissection, the Zero 2 is more enjoyable.
Who Should Buy the 7Hz Zero?
The original Zero is the right choice for a specific type of listener:
- Harman target and neutral reference seekers who want an IEM that sounds like accurate studio monitoring rather than consumer-tuned audio
- FPS gamers who need sharp imaging and treble clarity for directional audio cues
- Listeners who prefer detail over warmth — the Zero presents more perceived micro-detail and top-end sparkle
- First-time audiophile buyers who want to understand what a reference-tuned IEM actually sounds like before experimenting with more colored signatures
- Treble-forward genre listeners — the Zero suits classical, jazz, and acoustic music particularly well where upper-frequency articulation matters
Who Should Buy the 7Hz Zero 2?
The Zero 2 is the right choice for the majority of everyday listeners:
- Bass music lovers — EDM, hip-hop, pop, and electronic genres all benefit from the Zero 2’s added sub-bass and mid-bass weight
- Long listening session users — the smooth, forgiving treble makes it one of the least fatiguing options at this price tier
- Casual everyday listeners who want a fun, engaging sound signature without needing to think about tuning philosophy
- Beginners who find the original Zero too lean or dry — the Zero 2 has a more immediately satisfying, consumer-friendly presentation
- Treble-sensitive listeners who have found budget IEMs harsh in the past
How the Zero 2 Compares to Other Budget IEMs
Zero 2 vs. Moondrop Chu 2
The Moondrop Chu 2 is the most direct competitor to the Zero 2 at approximately the same ~$20–25 price point. The Chu 2 has more forward and prominent vocals, giving it a more mid-centric presentation that some listeners strongly prefer for acoustic and vocal-heavy music. The Zero 2 offers more sub-bass extension and a smoother treble, making it the better choice for bass-forward genres and long sessions. The Chu 2’s shell is smaller and may fit more ear canal shapes comfortably; the Zero 2’s shell is slightly larger and can cause fit issues for some users — a commonly reported concern in the r/iems community. The Chu 2 also features replaceable acoustic filters, which the Zero 2 does not have.
Zero 2 vs. Truthear Zero:Red
The Truthear x Crinacle Zero:Red occupies a similar price and philosophy space as the Zero 2 — both are Crinacle-collaborated budget IEMs with a more bass-emphasized, consumer-friendly tuning. The Zero:Red is widely regarded as slightly more technically capable with better resolution and staging, but at a marginally higher price point. If your budget stretches to the Zero:Red, it is worth considering. For strict sub-$25 buyers, the Zero 2 remains one of the most competitive options in the ChiFi budget IEM market.
Which Should You Choose?
Choose the 7Hz Zero if you are a detail-oriented listener, a neutral reference purist, or a gamer who needs sharp positional imaging. The original Zero is also the better entry point if you want to understand what the Harman target actually sounds like in an IEM before deciding whether you prefer more colored tuning.
Choose the 7Hz Zero 2 if you listen primarily to bass-forward music genres, want a relaxed and fatigue-free treble for long sessions, or simply want the most enjoyable and universally appealing sound signature for the price. The upgraded cable and extended low-frequency response make it the better value at just $5 more than the original.
For absolute beginners who are unsure where their preferences fall: buy the Zero 2. It has a more forgiving, immediately enjoyable sound that is unlikely to disappoint, while still being accurate enough to serve as a genuine audiophile gateway product.
Final Verdict
The 7Hz Zero 2 is the stronger all-around product in 2024. The dual-cavity driver upgrade, improved cable, extended bass response, and smoother treble make it the more technically refined IEM, and Crinacle’s tuning expertise ensures the added bass does not compromise the fundamental tonal balance. The original Zero remains a legitimate choice — specifically for Harman-neutral seekers and gamers — but for most buyers spending money in the budget IEM space, the Zero 2 is the clearer recommendation.
If you want neutral reference detail: buy the 7Hz Zero (~$20).
If you want a better all-around everyday IEM: buy the 7Hz Zero 2 (~$25).
Both are available from Linsoul and major marketplaces. At their respective price points, either purchase represents exceptional value in the budget ChiFi category.
Frequently Asked Questions
Is the 7Hz Zero 2 better than the original 7Hz Zero?
It depends on your preferences. The Zero 2 is better for most casual listeners — it has more bass, smoother treble, and an improved cable. The original Zero is better if you prefer a Harman-neutral, detail-forward sound signature. For general use and bass music, the Zero 2 wins. For reference listening and gaming, the original Zero holds its own.
What is the difference between the 7Hz Zero and Zero 2?
The Zero 2 features an upgraded 10mm dual-cavity dynamic driver with a PU+Metal composite diaphragm, approximately 3dB more low-end gain, a smoother treble, a silver-plated OFC coaxial cable upgrade, and slightly extended bass response down to 10Hz. It costs around $5 more than the original Zero. Both share the same 32-ohm impedance, 108dB sensitivity, and 0.78mm 2-pin connector.
Does the 7Hz Zero 2 have good bass?
Yes — the Zero 2 has noticeably more sub-bass and mid-bass than the original Zero. It was deliberately retuned by Crinacle with approximately 3dB of additional low-end gain for a more consumer-friendly, fun sound signature. It suits EDM, hip-hop, and pop well. It is not a bass-head IEM, but it delivers satisfying bass impact for a budget dynamic driver.
How does the Moondrop Chu 2 compare to the 7Hz Zero 2?
The Moondrop Chu 2 has more forward vocals and a more mid-centric presentation, while the Zero 2 offers more sub-bass extension and a smoother treble. The Chu 2 is smaller and may fit better for some ear canal shapes; the Zero 2’s shell is larger and less universally comfortable. Both are priced at approximately $20–25 and are competitive options at the budget tier.
Is the 7Hz Zero 2 good for long listening sessions?
Yes. The Zero 2’s smooth, laid-back treble makes it one of the most fatigue-free IEMs at the budget tier. Unlike the original Zero’s slightly elevated top end, the Zero 2 avoids harsh sibilance and listener fatigue even during extended use. It is a strong choice for commuting, work, or multi-hour listening sessions where comfort matters as much as sound quality.