Short answer: the Ultimate Ears UE7, though neither ranks well in its class. It ranks #1086 of 1291 in-ear headphones by sound quality, rated 2.6/5, at $999. The Fidue A91 Sirius ranks #1118, rated 2.3/5, at $899.99, $99.01 cheaper, not enough of a saving to outweigh the sound-quality gap. Both are rated below 3.0/5 among the 1291 in-ear headphones, and the ThieAudio Monarch MKIII, ranked #1 at $999, is a better place to start if sound quality matters.
The Ultimate Ears UE7 is the better-sounding pick. Its tonal tilt of -0.21 sits close to the target, so the overall balance is neither dark nor bright. The tradeoff: A Harman score of 56 places it in the lower part of the in-ear rankings.
The case for the Fidue A91 Sirius: A hybrid of one dynamic driver and four balanced armatures per side offers a multi-driver layout for listeners who want one. The catch: A preference score of 53 in crinacle’s measurement places its tuning far from what most listeners prefer.
Buy the Ultimate Ears UE7. It is rated higher for sound quality, and the $99.01 saving on the Fidue A91 Sirius is not enough to make up the difference.
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Its tonal tilt of -0.21 sits close to the target, so the overall balance is neither dark nor bright.
Ultimate Ears $999.00 eBay
A hybrid of one dynamic driver and four balanced armatures per side offers a multi-driver layout for listeners who want one.
Amazon $899.99 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
| Ultimate Ears UE7 | Fidue A91 Sirius | |
|---|---|---|
| Price | $999.00 | $899.99 |
| Ranked | #1086 of 1291 in In-Ear Headphones | #1118 of 1291 in In-Ear Headphones |
| Form Factor | In-ear | In-ear |
| Connection | Wired | Wired |
| Driver Type | Balanced armature | Hybrid (1 dynamic + 4 balanced armature) |
| Drivers | 3 x balanced armature | 1 x dynamic + 4 x balanced armature |
| Impedance | 17.5 ohms | 20 ohms |
| Sensitivity | 124 dB/mW | 113 dB |
| Frequency Response | 5Hz - 22kHz | 4Hz - 45kHz (Manufacturer specified) |
| Harman Preference Score | 56 (measured by crinacle, via AutoEQ) | 53 (measured by crinacle, via AutoEQ) |
| Deviation From Target | 3.46 dB standard deviation | 4.06 dB standard deviation |
| Tonal Tilt | -0.21 (negative is warmer, positive brighter) | +0.13 (negative is warmer, positive brighter) |
| Back | - | Closed |
| Built-in Microphone | - | No |
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