We compare products from their published specs and features; the verdicts below are our independent editorial opinions.
Updated: 2026-09-21 · 6 min read · Independent comparison
If you want a bass-forward, high-energy hybrid IEM with a detachable cable for tinkering and upgrades, choose CCA KZ ZST X; if you need a lightweight, low-distortion single-dynamic-driver IEM with a balanced tuning and an inline mic for calls and gaming, choose TANCHJIM Bunny.
• CCA KZ ZST X — biggest strength: A 1BA + 1DD hybrid setup (10mm dual-magnetic dynamic driver plus a 30095 balanced armature) that delivers a pronounced sub-bass boost and a V-shaped, energetic signature.
• CCA KZ ZST X — biggest trade-off: That V-shaped tuning pushes bass and treble forward, so listeners who want a neutral, flat response may find it colored; it's also the heavier package at 74 g.
• TANCHJIM Bunny — biggest strength: A single dual-chamber dynamic driver rated for under 0.05% harmonic distortion at 94dB, with a balanced tuning and a very light 3.5 g per earbud.
• TANCHJIM Bunny — biggest trade-off: No noise isolation is listed, and there's no detachable-cable upgrade path mentioned on this version — it's a simpler, more fixed package.
• Who each is for: Pick the ZST X if you want punchy bass and cable-swapping flexibility; pick the Bunny if you want low distortion, all-day comfort, and a mic for calls.
The ZST X is an update of a well-known design, and the spec sheet tells you what that means in practice. It pairs a 10mm dual-magnetic dynamic driver with a 30095 balanced armature — a hybrid configuration that splits the work between a moving-coil driver for punch and a balanced armature for detail. The result, per the listed tuning, is a V-shaped signature with a prominent sub-bass boost and a soundstage described as good in width and depth.
The build leans toward tinkering. You get a 4-strand silver-plated cable and a 3.5mm gold-plated plug, and — importantly — the cable is detachable via a 0.75mm 2-pin connection. That means you can replace a worn cable or swap in something else without retiring the earbuds. It also ships with a metal enclosure and a leatherette carrying case, and a media-control inline setup with an HD call microphone.
Who should skip it? If you want a neutral, reference-style tuning, or if you dislike any treble emphasis, this isn't the one. At 74 g for the package and with an over-ear-routed cable, it's also the bulkier, more involved wear of the two. And if you want the lightest possible earbud, the Bunny wins that contest outright.
TANCHJIM Bunny: Who It's For
The Bunny is built around a single dual-chamber dynamic driver — the opposite philosophy from the ZST X's hybrid. TANCHJIM lists harmonic distortion at under 0.05% at 94dB, which is the headline number here: low distortion generally means cleaner mids and tighter control over bass, rather than boom. A PET-titanium composite diaphragm is cited for stability and elasticity, and a low-distortion waveguide cover is said to sharpen high-frequency clarity.
Two other design details matter. First, a patented ultra-smooth inner cavity wall that reduces high-frequency damping and controls dispersion, which TANCHJIM says yields smoother, more linear, extended ultra-highs. Second, an acoustic maze structure that deepens low frequencies. Together they aim at a balanced sound rather than a V-shape; the standard Bunny is tuned to TANCHJIM's target curve for even coverage across the range.
Comfort is where this thing stands apart. Each earbud is 3.5 g and made from a medical-grade, highly transparent PC shell with a streamlined, ergonomic shape. That's a genuinely low weight for an IEM, and it's the kind of spec that matters if you wear earbuds for hours. Connectivity is 3.5mm wired, and it's listed as compatible with smartphones, laptops, desktops and the Switch, with a version that includes a mic. The frequency range is listed as 8Hz–48kHz and impedance at 30 ohms.
Who should buy it? Anyone who prioritizes a clean, balanced sound, low distortion, and a near-weightless fit — students, office listeners, gamers who want a mic and long-session comfort. Who should skip it? If you specifically want a big sub-bass shelf, or you want a detachable-cable upgrade path, the ZST X fits you better. Note that no noise isolation is listed for the Bunny, so it's less of a commuter/airplane tool on paper.
• Best for deep, boosted bass → CCA KZ ZST X. The sub-bass boost is the defining feature of its tuning.
• Best for clean, low-distortion mids → TANCHJIM Bunny. Under 0.05% harmonic distortion at 94dB is the spec to care about here.
• Best for long-session comfort → TANCHJIM Bunny. 3.5 g per earbud versus a 74 g package for the ZST X.
• Best for cable upgrades and repairs → CCA KZ ZST X. The 0.75mm 2-pin detachable cable is the practical advantage.
• Best for noisy commutes and flights → CCA KZ ZST X. Its listed sound isolation is the stronger claim of the two.
• Best for easy driving from a phone → CCA KZ ZST X. 12 ohms is very low impedance; the Bunny's 30 ohms needs a touch more power.
• Best for a neutral, balanced tuning → TANCHJIM Bunny. It's tuned to a target curve rather than a V-shape.
• Best for tinkerers who like EQ → TANCHJIM Bunny. The DSP-oriented version of this model supports preset profiles and parametric EQ adjustment via an app.
If I had to pick one for myself, I'd take the TANCHJIM Bunny. In my opinion, the combination of a low-distortion dual-chamber driver, a balanced tuning, and a 3.5 g-per-side fit is the more versatile everyday package — it works for music, calls and long gaming sessions without fatigue. The ZST X is the better choice if bass is your priority and you value the detachable cable, and I wouldn't argue with anyone who picks it for that. But for most people who want one pair that does everything reasonably well, I recommend the Bunny. Check the current price on Amazon before deciding, since budgets shift.
FAQ
Yes, on paper. The ZST X uses a hybrid 1BA + 1DD setup with a deliberately prominent sub-bass boost and a V-shaped signature, while the Bunny aims for a balanced response with deep-but-controlled low end from its acoustic maze design. If bass quantity is your goal, the ZST X is the fit.
The TANCHJIM Bunny. Each earbud weighs 3.5 g and uses a medical-grade transparent PC shell with an ergonomic, streamlined shape. The ZST X is a 74 g package and uses an over-ear cable routing, which is a more involved fit.
The version listed here is the 3.5mm model with a mic, and a low-noise microphone circuit is part of the design. That makes it usable for calls and voice chat straight from a phone, laptop or handheld console.
On the CCA KZ ZST X, yes — it has a detachable 0.75mm 2-pin cable, which also opens up upgrade options. The Bunny's listing doesn't specify a detachable cable, so treat it as a fixed-cable design.
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