Short answer: a tie on sound quality. Both are rated 3.6/5 (#746 and #730 of 1291 in-ear headphones) at nearly the same price ($22.99 vs $20.99), so choose on features and fit.
Why pick the AGASound AGA One: A broadly balanced tuning with a preference score of 69 against the Harman target. The catch: An uneven response, 2.1 dB standard deviation from target.
Why pick the TRN CS4: A very cheap single dynamic in-ear with a 69 Harman preference score and full sub-bass extension down to 20 Hz. Watch for: Its score rests on three measurements.
Buy the AGASound AGA One or the TRN CS4 on features: they are rated the same for sound quality at close to the same price.
Want more options? Browse the full Headphones rankings.
A broadly balanced tuning with a preference score of 69 against the Harman target.
Amazon $22.99 eBay
A very cheap single dynamic in-ear with a 69 Harman preference score and full sub-bass extension down to 20 Hz.
Amazon $20.99 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.
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Specifications Side By Side
| AGASound AGA One | TRN CS4 | |
|---|---|---|
| Price | $22.99 | $20.99 |
| Ranked | #746 of 1291 in In-Ear Headphones | #730 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Harman Preference Score | 69 (median of 6 squig.link measurements, calibrated to AutoEQ) | 69 (median of 3 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 2.13 dB standard deviation | 2.25 dB standard deviation |
| Tonal Tilt | -0.61 (negative is warmer, positive brighter) | -0.49 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+1.7 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+0.9 dB at 30 Hz) |
| Connection | Wired (3.5mm) | Wired |
| Driver Type | Dynamic | Dynamic |
| Drivers | 1 Dynamic (10mm) | 1 x 10mm dynamic |
| Sensitivity | - | 106 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 AGASound AGA One from audioamigo, kuping-sensi, pw, soundignity, tdl and tonedeafmonk; the TRN CS4 from ankramutt, fahryst and ianfann, all via squig.link.
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