Short answer: the Tin HiFi P2 Ultra. It ranks #797 of 1291 in-ear headphones by sound quality, rated 3.5/5, at $599; the OpenAudio Mercury ranks #900, rated 3.3/5, and costs $599.99, so there is little reason to consider the other one.
What the Tin HiFi P2 Ultra does well: A 12mm planar IEM in a gold plated shell with bass right on the Harman target, scoring 68 across five measurements. Watch for: Treble sits about 4.7 dB below target, a dark, relaxed balance.
The case for the OpenAudio Mercury: A bass-forward tuning with about 4.7 dB of extra sub-bass below 60 Hz and a 5.8 dB lift at 30 Hz, so kick drums and synth bass carry deep rumble. The catch: A 6.6 dB dip near 5.9 kHz in squig.link measurements softens vocal consonants and the leading edge of guitars and snares.
Buy the Tin HiFi P2 Ultra. It is rated higher for sound quality than the OpenAudio Mercury 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 12mm planar IEM in a gold plated shell with bass right on the Harman target, scoring 68 across five measurements.
Amazon $599.00 eBay
A bass-forward tuning with about 4.7 dB of extra sub-bass below 60 Hz and a 5.8 dB lift at 30 Hz, so kick drums and synth bass carry deep rumble.
Shenzhenaudio $599.99 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
| Tin HiFi P2 Ultra | OpenAudio Mercury | |
|---|---|---|
| Price | $599.00 | $599.99 |
| Ranked | #797 of 1291 in In-Ear Headphones | #900 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Back | Closed | Closed |
| Connection | Wired | Wired |
| Driver Type | Planar Magnetic | Hybrid (1 dynamic + 4 balanced armature) |
| Drivers | 1 x 12mm planar | 1 x 9.2mm dynamic + 4 x balanced armature |
| Impedance | 32 ohms | 8 ohms |
| Sensitivity | 98 dB | 110 dB/mW |
| Harman Preference Score | 68 (median of 5 squig.link measurements, calibrated to AutoEQ) | 65 (measured by crinacle, via AutoEQ) |
| Deviation From Target | 2.47 dB standard deviation | 2.46 dB standard deviation |
| Tonal Tilt | -0.51 (negative is warmer, positive brighter) | -1.07 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (-2.5 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+5.8 dB at 30 Hz) |
| Frequency Response | - | 5Hz - 40kHz (Manufacturer specified) |
| Built-in Microphone | - | No |
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 Tin HiFi P2 Ultra from atechreviews, audioamigo, csi-zone, ducbloke and soundignity; the OpenAudio Mercury from atechreviews, bukanaudiophile, hbb, precog and superreview, all via squig.link.
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