Polk Audio Signa S4 vs Sonos Arc Ultra ARCG2US1BLK
Sonos Arc Ultra ARCG2US1BLK
The short answer
Sonos Arc Ultra ARCG2US1BLK comes out ahead overall with 7.8/10 against 7.4/10 for the Polk Audio Signa S4. Polk Audio Signa S4 is stronger on ease of setup & use for seniors and value. Sonos Arc Ultra ARCG2US1BLK is stronger on dialogue clarity, dialogue boost range & controls, overall sound quality and safety, energy & repairability. At current verified prices, the Polk Audio Signa S4 costs about $650.00 less.
- Choose the Polk Audio Signa S4 if: Families who want movie-night bass and Atmos but still need a real center channel and adjustable voice lift.
- Choose the Sonos Arc Ultra ARCG2US1BLK if: Households willing to spend for top-tier sound, where a family helper can do the app setup, and someone needs hearing-loss-oriented speech enhancement.
Scores by criterion
| Criterion | Polk Audio Signa S4 | Sonos Arc Ultra ARCG2US1BLK |
|---|---|---|
| Dialogue clarity | 8.3Lab-tested center channel (RTINGS). | 9.2Discrete center channel plus RNID-tuned AI. Praised by RTINGS and Tom's Guide. |
| Dialogue boost range & controls | 7.03 VoiceAdjust levels plus Night Mode. | 8.5Four AI levels aimed at hearing loss. |
| Ease of setup & use for seniors | 7.0HDMI ARC/CEC and no app, but a sub to place and power. | 6.0TV-remote control works after setup, but the app is required and drew a 2024 backlash. |
| Overall sound quality | 7.5Atmos with a sub, but RTINGS says it lacks deep bass. | 9.59.1.4 Atmos in one box. |
| Value | 6.8$449 is fair for a 3.1.2 system. | 5.0$899-$1,099 is steep if dialogue is the goal. |
| Safety, energy & repairability | 5.0Neutral: no parts or refurbishment evidence found. 2021 design, still sold new. | 7.5Sonos discloses lower idle power, screw-based disassembly and halogen-free boards. No recall found. |
Specifications
| Spec | Polk Audio Signa S4 | Sonos Arc Ultra ARCG2US1BLK |
|---|---|---|
| Dialogue feature | VoiceAdjust | AI Speech Enhancement (RNID-developed) |
| Dialogue enhancement levels | 3 levels | 4 levels |
| Dedicated center channel / speech driver | Yes | Yes |
| Channel configuration | 3.1.2 | 9.1.4 |
| Dolby Atmos | Yes | Yes |
| Separate subwoofer included | Yes | No |
| HDMI ARC/eARC | Yes | Yes |
| Optical input | Yes | — |
| Bluetooth | Yes | Yes |
Polk Audio Signa S4
Pros
- Dedicated center channel
- Three-level VoiceAdjust raises voices only
- Night Mode lifts speech and cuts bass
- Wireless subwoofer included
- Dolby Atmos and Bluetooth
Cons
- Lacks deep low bass, and surround is unimpressive
- Subwoofer needs a second power outlet
- Older design; a successor model exists
- Fewer dialogue levels than the ZVOX bars
A balanced choice for families. It gives up some simplicity for better movie sound while still treating dialogue seriously.
Full Polk Audio Signa S4 review →Sonos Arc Ultra ARCG2US1BLK
Pros
- Discrete center channel
- Four-level AI Speech Enhancement developed with RNID
- Excellent music and movie sound with Dolby Atmos
- TV-remote control over eARC after setup
- Lower idle power than the original Arc, per Sonos
Cons
- Very expensive; Best Buy and Walmart have listed it well below Amazon
- Setup requires the Sonos app
- The Sonos app redesign drew complaints, including about accessibility
- Adding a sub or rear speakers costs more
The strongest performer for dialogue and sound overall. Buy it when budget allows and a family helper can do the one-time setup.
Full Sonos Arc Ultra ARCG2US1BLK review →Both products are part of our guide The Best Soundbars for Dialogue Clarity and Seniors of 2026, where you can see every pick, how we score and current prices from each retailer.