Short answer: the KLH Ultimate One, though neither ranks well in its class. It ranks #415 of 481 over-ear headphones by sound quality, rated 2.5/5, at $325.11; the Sony INZONE H9 II ranks #440, rated 2.1/5, and costs $348, so there is not much of a tradeoff to weigh. Both are rated below 3.0/5 among the 481 over-ear headphones, and the HIFIMAN Ananda Nano, ranked #6 at $319, is a better place to start if sound quality matters.
The KLH Ultimate One is the better-sounding choice. Bass from 60 to 200 Hz runs about 8.5 dB above target with sub-bass 5 dB up, so bass lovers get heavy, rumbling lows from an open headphone. The tradeoff: In oratory1990’s measurement the treble also sits about 5 dB above target from 3 to 16 kHz with a 9.6 dB peak near 6 kHz, which can make vocals and cymbals sound sharp and tiring at volume.
Why pick the Sony INZONE H9 II: Active noise cancelling, 30 hours of battery (ANC off), a built-in microphone, LC3 support and a wired option make it a flexible gaming headset at 0.6 lbs (260 g). The tradeoff: A 9.2 dB peak near 7.2 kHz and treble about 5 dB over target make cymbals and sibilance edgy, while a dip near 3.9 kHz pushes voices back, for a preference score of 38.
Buy the KLH Ultimate One. It is rated higher for sound quality than the Sony INZONE H9 II and costs less, which makes it the one to get unless you need something the other one does better.
Still deciding? The full Headphones rankings cover every ranked option.
Bass from 60 to 200 Hz runs about 8.5 dB above target with sub-bass 5 dB up, so bass lovers get heavy, rumbling lows from an open headphone.
Amazon $325.11 eBay
Active noise cancelling, 30 hours of battery (ANC off), a built-in microphone, LC3 support and a wired option make it a flexible gaming headset at 260 g.
Amazon $348.00 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
| KLH Ultimate One | Sony INZONE H9 II | |
|---|---|---|
| Price | $325.11 | $348.00 |
| Ranked | #415 of 481 in Over-Ear Headphones | #440 of 481 in Over-Ear Headphones |
| Form Factor | Over-ear | Over-ear |
| Harman Preference Score | 49 (measured by oratory1990, via AutoEQ) | 38 (median of 2 squig.link measurements, calibrated to AutoEQ) |
| Deviation From Target | 3.96 dB standard deviation | 4.30 dB standard deviation |
| Tonal Tilt | -1.03 (negative is warmer, positive brighter) | -1.46 (negative is warmer, positive brighter) |
| Sub-bass Extension | Within 6 dB of target down to 20 Hz (+2.6 dB at 30 Hz) | Within 6 dB of target down to 20 Hz (+1.3 dB at 30 Hz) |
| Connection | Wired | Wireless and wired |
| Back | Open | Closed |
| Driver Type | Dynamic | Dynamic |
| Drivers | 1 x 50mm dynamic | 1 x 30mm dynamic |
| Impedance | 32 ohms | 21 ohms |
| Sensitivity | 97 dB/mW | 100 dB/mW |
| Weight | 0.7 lbs (340 g) | 0.6 lbs (260 g) |
| Frequency Response | 18Hz - 22kHz (Manufacturer specified) | - |
| Built-in Microphone | No | Yes |
| Active Noise Cancelling | - | Yes |
| Battery Life | - | 30 hours (ANC off, Manufacturer specified) |
| Bluetooth Version | - | 5.3 |
| Bluetooth Codecs | - | SBC, AAC, LC3 |
| IP Rating | - | None |
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