Short answer: the KZ ZST. It ranks #632 of 1291 in-ear headphones by sound quality, rated 3.7/5, at $22.99; the iBasso Jr. Gelato ranks #742, rated 3.6/5, and costs $23, which makes this an easy call rather than a real tradeoff.
What the KZ ZST does well: In oratory1990’s measurement the preference score is 70, with bass about 2.3 dB above target from 60 to 200 Hz for extra warmth and punch, and sub-bass tracking the target within 0.1 dB. The catch: A 9.4 dB dip near 4.4 kHz and 3.7 dB lower presence from 3 to 6 kHz pull back vocal clarity and the attack of snares and guitars.
What the iBasso Jr. Gelato does well: A single dynamic IEM in a stainless steel shell. Watch for: Sub-bass falls about 3.4 dB short at 30 Hz.
Buy the KZ ZST. It is rated higher for sound quality than the iBasso Jr. Gelato and costs less, which makes it the one to get unless you need something the other one does better.
Looking for alternatives? See the complete Headphones rankings.
In oratory1990’s measurement the preference score is 70, with bass about 2.3 dB above target from 60 to 200 Hz for extra warmth and punch, and sub-bass tracking the target within 0.1 dB.
Amazon $22.99 eBay
A single dynamic IEM in a stainless steel shell.
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Specifications Side By Side
| KZ ZST | iBasso Jr. Gelato | |
|---|---|---|
| Price | $22.99 | $23 |
| Ranked | #632 of 1291 in In-Ear Headphones | #742 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Harman Preference Score | 70 (measured by oratory1990, via AutoEQ) | 69 (median of 3 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 2.31 dB standard deviation | 2.61 dB standard deviation |
| Tonal Tilt | -0.47 (negative is warmer, positive brighter) | +0.02 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+0.1 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (-3.4 dB at 30 Hz) |
| Connection | Wired | Wired |
| Driver Type | Hybrid (1 dynamic + 1 balanced armature) | Dynamic |
| Drivers | 1 x 10mm dynamic + 1 x balanced armature | 1 x 10mm dynamic |
| Frequency Response | 20Hz - 20kHz (Manufacturer specified) | - |
| Back | Closed | Closed |
| Impedance | - | 18 ohms |
| Sensitivity | - | 108 dB/mW |
Frequency Response Compared
Both headphones’ measurements overlaid on the Harman target. Above the target sounds louder in that range, below it quieter. Each curve is the median of several independent measurements, shifted so its 500 Hz to 2 kHz average sits at 0 dB, so only the tuning is compared.
Measurement data: the KZ ZST from audioamigo, bassyalexander, hbb, iemocean, isaiahse, melatonin and sl0the; the iBasso Jr. Gelato from eplv, lumerion and soundignity, all via squig.link.
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