Short answer: the Erand Resonance 5. It ranks #593 of 1291 in-ear headphones by sound quality, rated 3.8/5, at $199.99; the Akoustyx S-6 ranks #657, rated 3.7/5, and costs $200, so there is little reason to consider the other one.
Why pick the Erand Resonance 5: A $200 tribrid that measures well (score 71 across thirteen measurements) with bass right on target and full sub-bass, plus swappable 3.5mm and 4.4mm plugs. The tradeoff: Treble sits about 4.0 dB below target, so it can sound smooth and a little dark next to brighter IEMs.
The case for the Akoustyx S-6: A single planar magnetic IEM with full sub-bass extension to 20 Hz and a Harman preference score of 70 across three measurements. Watch for: Treble sits about 2.4 dB above target, so it can sound bright.
Buy the Erand Resonance 5. It is rated higher for sound quality than the Akoustyx S-6 and costs less, so it is the default pick unless a specific strength of the other one matters more to you.
Want more options? Browse the full Headphones rankings.
A $200 tribrid that measures well (score 71 across thirteen measurements) with bass right on target and full sub-bass, plus swappable 3.5mm and 4.4mm plugs.
Amazon $199.99 eBay
A single planar magnetic IEM with full sub-bass extension to 20 Hz and a Harman preference score of 70 across three measurements.
Akoustyx $200.00 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
| Erand Resonance 5 | Akoustyx S-6 | |
|---|---|---|
| Price | $199.99 | $200.00 |
| Ranked | #593 of 1291 in In-Ear Headphones | #657 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Connection | Wired | Wired |
| Driver Type | Tribrid | Planar Magnetic |
| Drivers | 2 x dynamic + 2 x balanced armature + 1 x micro planar | 1 x planar magnetic |
| Impedance | 20 ohms | 18 ohms |
| Sensitivity | 106 dB at 1 kHz | 108 dB SPL |
| Frequency Response | 10Hz - 35kHz | - |
| Harman Preference Score | 71 (median of 13 squig.link measurements, calibrated to AutoEQ) | 70 (median of 3 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 2.09 dB standard deviation | 2.24 dB standard deviation |
| Tonal Tilt | -0.69 (negative is warmer, positive brighter) | -0.32 (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 (+5.2 dB at 30 Hz) |
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 Erand Resonance 5 from aftersound, atechreviews, audioamigo, bassaudio, fernandagunsan, jaytiss, kuping-sensi, lumerion, practiphile, precog, soundcheck39, superreview and tonedeafmonk; the Akoustyx S-6 from dentreviews, superreview and treblewellxtended, all via squig.link.
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