Short answer: the KZ ZST. It ranks #632 of 1291 in-ear headphones by sound quality, rated 3.7/5, at $22.99; the AGASound AGA One ranks #746, rated 3.6/5, at $22.99. Close enough in price that the sound-quality gap is the deciding factor.
Why pick the KZ ZST: 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. Watch for: 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.
Why pick the AGASound AGA One: A broadly balanced tuning with a preference score of 69 against the Harman target. The tradeoff: An uneven response, 2.1 dB standard deviation from target.
Buy the KZ ZST. It is rated higher for sound quality than the AGASound AGA One at the same price, so only choose the other one for a particular feature it 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 broadly balanced tuning with a preference score of 69 against the Harman target.
Amazon $22.99 eBayPrices on this page were last checked October 16, 2026 at 5:46 PM UTC. Product prices and availability are accurate as of that date/time and are subject to change; the price and availability shown on Amazon at the time of purchase will apply to the purchase of this product.
As an eBay Partner, we may be compensated if you make a purchase.
Specifications Side By Side
| KZ ZST | AGASound AGA One | |
|---|---|---|
| Price | $22.99 | $22.99 |
| Ranked | #632 of 1291 in In-Ear Headphones | #746 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Harman Preference Score | 70 (measured by oratory1990, via AutoEQ) | 69 (median of 6 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 2.31 dB standard deviation | 2.13 dB standard deviation |
| Tonal Tilt | -0.47 (negative is warmer, positive brighter) | -0.61 (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 (+1.7 dB at 30 Hz) |
| Connection | Wired | Wired (3.5mm) |
| Driver Type | Hybrid (1 dynamic + 1 balanced armature) | Dynamic |
| Drivers | 1 x 10mm dynamic + 1 x balanced armature | 1 Dynamic (10mm) |
| Frequency Response | 20Hz - 20kHz (Manufacturer specified) | - |
| Back | Closed | Closed |
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 AGASound AGA One from audioamigo, kuping-sensi, pw, soundignity, tdl and tonedeafmonk, all via squig.link.
Related Headphone Comparisons
More top alternatives to KZ ZST: