Overview

Arc Ultra pairs 14 drivers with 15 Class-D amps, HDMI eARC, Bluetooth 5.3, Wi-Fi 6, and Trueplay for both iOS and Android[1]. Sonos markets a 9.1.4-like spatial experience from a single bar. US MSRP is 999 USD (JP direct price 149,800円), announced Oct 15, 2024 with availability from Oct 29, 2024[2][3].

Scientific Validity

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Independent data (RTINGS) reports stereo max ~93.0 dB SPL, center max ~95.3 dB SPL, weighted THD (center) ~0.63% @80 dB / ~1.90% max, stereo low-frequency extension ~46.9 Hz, and stereo standard error ~2.50 dB[4]. These indicate solid linearity and dialog clarity for a single-bar system; height perception is room-dependent but can be convincing within favorable acoustics[4][6].

Technology Level

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The Sound Motion flat woofer (four motors, dual membrane) increases bass output without added bulk, while seven tweeters (two up-firing) and six mid-woofers are each driven by dedicated amplification[1]. Features include Speech Enhancement (four levels), Trueplay for iOS/Android, AirPlay 2, Bluetooth 5.3. Connectivity is HDMI eARC/ARC only—no HDMI passthrough—and DTS Digital Surround is listed with a decoder note, not a licensed logo[1].

Cost-Performance

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As an equal-or-better alternative at a lower street price, we select Samsung HW-Q800D (5.1.2 with bundled wireless sub, HDMI input with 4K/60 passthrough, 7-band EQ)[5]. Typical US pricing is 799 USD vs 999 USD for Arc Ultra[1][5].
CP = 799 USD ÷ 999 USD = 0.8.

Reliability & Support

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Sonos’ long update cycle and cohesive ecosystem are strengths, but the May 2024 app overhaul shipped with regressions and missing features, prompting a public apology and a published improvement roadmap[7]. Stability has improved since, yet the recent history warrants a slightly conservative score.

Rationality of Design Philosophy

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Prioritizing a single-bar immersive experience and adopting the Sound Motion concept is sensible. However, no HDMI passthrough and no included sub at this price reduce practicality versus rivals with richer I/O and bundled bass performance[1][5].

Advice

• Choose Arc Ultra if you value a clean, single-bar setup and tight Sonos integration[1].
• Prefer Samsung HW-Q800D (799 USD) if you want stronger bass out of the box and HDMI passthrough[5].
• If you go with Arc Ultra, adding Sub 4 (109,800円) significantly boosts cinematic impact[8].

References

[1] Sonos, “Arc Ultra: Home Theater Soundbar with Dolby Atmos (US product page)”, https://www.sonos.com/en-us/shop/arc-ultra , accessed Aug 16, 2025 (14 drivers/15 amps, Trueplay iOS/Android, eARC-only, DTS note, 999 USD)
[2] Sonos (JP), “Arc Ultra (product page)”, https://www.sonos.com/ja-jp/shop/arc-ultra , accessed Aug 16, 2025 (JP price 149,800円)
[3] Sonos, “Sonos Reveals Arc Ultra, its New Soundbar Featuring Sound Motion (Investor News)”, https://investors.sonos.com/news-and-events/investor-news/latest-news/2024/Sonos-Reveals-Arc-Ultra-its-New-Soundbar-Featuring-Sound-Motion/default.aspx , Oct 15, 2024 (announcement, price, availability)
[4] RTINGS, “Sonos Arc Ultra Review”, https://www.rtings.com/soundbar/reviews/sonos/arc-ultra , published Nov 28, 2024 (max SPL/THD, LFE, standard error)
[5] RTINGS, “Samsung HW-Q800D Review”, https://www.rtings.com/soundbar/reviews/samsung/hw-q800d , published Jul 26, 2024 (HDMI in with 4K/60 passthrough, bundled sub, pricing context)
[6] The Verge, “Sonos Arc Ultra review: don’t call it a comeback (yet)”, https://www.theverge.com/24315195/sonos-arc-ultra-soundbar-review-dolby-atmos-more-bass , Dec 10, 2024 (usage/placement context)
[7] The Verge, “Sonos CEO apologizes for disastrous rollout of new app”, https://www.theverge.com/2024/7/25/24206203/sonos-ceo-apology-redesigned-app-controversy , Jul 25, 2024 (app issues and roadmap)
[8] Sonos (JP), “Wireless Audio Store (Sub 4 price listing)”, https://www.sonos.com/ja-jp/shop , accessed Aug 16, 2025 (Sub 4: 109,800円)

(2025.8.16)