Soundbars / Polk Audio Signa S4 vs Sonos Arc Ultra
Polk Audio Signa S4 vs Sonos Arc Ultra
Sonos Arc Ultra
The best one-box Atmos bar — real bass, no sub needed, but no HDMI input.
Wins overall by 1.6 points
Quick Verdict
A 1.6-point gap makes the Sonos Arc Ultra the straightforward choice here. The best one-box Atmos bar — real bass, no sub needed, but no HDMI input.
The Polk Audio Signa S4 and Sonos Arc Ultra are both closely matched soundbar models, and the Polk Audio Signa S4 is $650 cheaper than the Sonos Arc Ultra ($449 vs $1,099). On Connectivity, the Sonos Arc Ultra leads (7.5 vs 4.5/10) — HDMI inputs and passthrough, eARC, Wi-Fi and streaming protocol support. On Features, the Sonos Arc Ultra leads (8.5 vs 5.5/10) — room calibration, TV-brand integration, app control and expandability. On Design & Build, the Sonos Arc Ultra leads (9.0 vs 6.5/10) — finish, size relative to a TV, and how well it fits a living room. Overall, the Sonos Arc Ultra scores 8.4/10 across our 8 scoring categories versus 6.8/10 for the Polk Audio Signa S4. Below, we break down the full spec sheet, category-by-category scores, and exactly who should buy which one.
Side-by-Side Comparison
| Spec | Polk Audio Signa S4 | Sonos Arc Ultra |
|---|---|---|
| Price | $449.00 | $1099.00 |
| Release Year | 2022 | 2024 |
| Channels | 3.1.2 | 9.1.4 (14 drivers: 9 tweeters, 6 mid-woofers, plus the Sound Motion woofer) |
| Total Power (W) | Not published by the manufacturer | Sonos does not publish power ratings |
| Subwoofer | Included (wireless), 5.9-inch driver | Built in (Sound Motion woofer); Sonos Sub 4 or Sub Mini optional |
| Rear Speakers | None — Polk's SR2 wireless surrounds pair with the MagniFi range, not the Signa S4 | Optional add-on — Sonos Era 300 or Era 100 pair as wireless surrounds |
| Dolby Atmos | Yes | Yes |
| DTS:X | No | No |
| HDMI Ports (ports) | 1 | 1 |
| HDMI Passthrough | None — eARC output only | None — there is no HDMI input at all, only eARC out |
| eARC | Yes | Yes |
| Wi-Fi & Streaming | None | Wi-Fi 6 with AirPlay 2 and Spotify Connect; Chromecast is not supported |
| Bluetooth | Not published by the manufacturer | 5.3 |
| Voice Assistant | None | Sonos Voice Control and Amazon Alexa built in |
| Warranty | 12 months | 12 months |
| Colors | Black | Black, White |
Category Scores
Sound Quality
The Sonos Arc Ultra leads clearly here, 9.2 against 7.5 — a 1.7-point margin on overall tonal balance, clarity and detail. If that is what you are buying for, the Polk Audio Signa S4 does not close the gap elsewhere.
Bass
The Sonos Arc Ultra leads clearly here, 8.5 against 7.5 — a 1.0-point margin on low-end weight and extension, with or without a separate subwoofer. If that is what you are buying for, the Polk Audio Signa S4 does not close the gap elsewhere.
Dialogue Clarity
The Sonos Arc Ultra leads clearly here, 8.5 against 8.0 — a 0.5-point margin on how well speech cuts through a busy soundtrack. If that is what you are buying for, the Polk Audio Signa S4 does not close the gap elsewhere.
Surround & Height
The Sonos Arc Ultra leads clearly here, 9.0 against 7.0 — a 2.0-point margin on dolby Atmos height effect and how convincingly it places surround audio. If that is what you are buying for, the Polk Audio Signa S4 does not close the gap elsewhere.
Connectivity
The Sonos Arc Ultra leads clearly here, 7.5 against 4.5 — a 3.0-point margin on HDMI inputs and passthrough, eARC, Wi-Fi and streaming protocol support. If that is what you are buying for, the Polk Audio Signa S4 does not close the gap elsewhere.
Features
The Sonos Arc Ultra leads clearly here, 8.5 against 5.5 — a 3.0-point margin on room calibration, TV-brand integration, app control and expandability. If that is what you are buying for, the Polk Audio Signa S4 does not close the gap elsewhere.
Design & Build
The Sonos Arc Ultra leads clearly here, 9.0 against 6.5 — a 2.5-point margin on finish, size relative to a TV, and how well it fits a living room. If that is what you are buying for, the Polk Audio Signa S4 does not close the gap elsewhere.
Value
The Polk Audio Signa S4 leads clearly here, 7.5 against 7.0 — a 0.5-point margin on performance and features relative to price. If that is what you are buying for, the Sonos Arc Ultra does not close the gap elsewhere.
Best For
Choose the Polk Audio Signa S4 if…
- • You want to spend less — it's $650 cheaper.
Choose the Sonos Arc Ultra if…
- • Connectivity matters most to you — the Sonos Arc Ultra scores 7.5/10 here (HDMI inputs and passthrough, eARC, Wi-Fi and streaming protocol support).
- • Features matters most to you — the Sonos Arc Ultra scores 8.5/10 here (room calibration, TV-brand integration, app control and expandability).
- • Design & Build matters most to you — the Sonos Arc Ultra scores 9.0/10 here (finish, size relative to a TV, and how well it fits a living room).
- • Surround & Height matters most to you — the Sonos Arc Ultra scores 9.0/10 here (dolby Atmos height effect and how convincingly it places surround audio).
- • Sound Quality matters most to you — the Sonos Arc Ultra scores 9.2/10 here (overall tonal balance, clarity and detail).
Pros & Cons
Polk Audio Signa S4
Pros
- +True up-firing height drivers rather than virtualised Atmos, which most bars at this price lack
- +VoiceAdjust genuinely helps with mumbled dialogue
- +Dolby Atmos Certified
- +Included wireless subwoofer
Cons
- −No Wi-Fi or smart features of any kind
- −No DTS:X support
- −Cannot be expanded with rear speakers
- −2022 hardware still selling at a 2022 price
- −42 inches wide, so it needs a wide TV stand
Sonos Arc Ultra
Pros
- +Widely rated the best one-box Atmos bar you can buy
- +The Sound Motion driver produces genuine bass without a separate subwoofer
- +Trueplay room tuning adapts it to your room
- +Superb build and finish
Cons
- −No HDMI input at all, which is a real problem if your TV has only one spare HDMI port
- −No DTS:X or DTS-HD decoding
- −Deliberately brand-agnostic, so no TV-brand features like Q-Symphony
- −Some controls sit on the rear, awkward when wall-mounted
- −List price rose from $999 to $1,099
Shop by Need
FAQs
Is the Polk Audio Signa S4 or Sonos Arc Ultra better overall?+
Based on our 8-category scoring, the Sonos Arc Ultra comes out ahead overall. See the full breakdown in the scores section above — the right pick still depends on which categories matter most for your use case.
Which is better for Connectivity, the Polk Audio Signa S4 or the Sonos Arc Ultra?+
The Sonos Arc Ultra scores higher on Connectivity (7.5/10 vs 4.5/10) — HDMI inputs and passthrough, eARC, Wi-Fi and streaming protocol support.
Which is better for Features, the Polk Audio Signa S4 or the Sonos Arc Ultra?+
The Sonos Arc Ultra scores higher on Features (8.5/10 vs 5.5/10) — room calibration, TV-brand integration, app control and expandability.
Which is better for Design & Build, the Polk Audio Signa S4 or the Sonos Arc Ultra?+
The Sonos Arc Ultra scores higher on Design & Build (9.0/10 vs 6.5/10) — finish, size relative to a TV, and how well it fits a living room.
Which is better for Surround & Height, the Polk Audio Signa S4 or the Sonos Arc Ultra?+
The Sonos Arc Ultra scores higher on Surround & Height (9.0/10 vs 7.0/10) — dolby Atmos height effect and how convincingly it places surround audio.
Is the Polk Audio Signa S4 worth the price difference over the Sonos Arc Ultra?+
The Polk Audio Signa S4 is the cheaper option at $449 versus $1,099. Whether the pricier model is "worth it" depends on how much you value its lead in Connectivity.
What's the warranty on the Polk Audio Signa S4 vs the Sonos Arc Ultra?+
The Polk Audio Signa S4 ships with a 12-month warranty; the Sonos Arc Ultra ships with a 12-month warranty. Always confirm current terms on the manufacturer's site before buying.
Should I wait for the next model instead of buying either of these?+
If either model is more than two years old, a successor may be close — check the "Latest Model" link on each product page. Otherwise, both are current, well-supported options and there's no strong reason to wait.
Cheaper Option
Sony BRAVIA Theater Bar 5 (HT-B500) — $349.99
Premium Option
LG S95AR — $1699.00
Specifications and prices for both products last verified . Scores are calculated from published specifications — see how we compare products.