Choosing Between Modern Dolby Atmos Soundbars: An In-Depth Comparison

For anyone looking to upgrade their TV audio experience without the complexity of a full surround sound system, Dolby Atmos soundbars offer an compelling solution. Let's dive deep into comparing the recently released Polk Audio Signa S4 ($269.85) and the brand new Sonos Arc Ultra ($949.05), two systems that take different approaches to delivering immersive sound.

Understanding Modern Soundbar Technology

Today's soundbars have evolved far beyond simple stereo speakers. They now use sophisticated audio processing and carefully positioned drivers (individual speakers) to create virtual surround sound effects that can rival traditional multi-speaker setups. Dolby Atmos adds another dimension by incorporating height channels, allowing sounds to appear to come from above your head.

Core Sound Performance

Bass Response and Impact

The Polk Signa S4 takes a traditional approach by including a separate wireless subwoofer. This dedicated bass unit can be placed anywhere in your room and handles the low frequencies that give movies their impact. The sub connects automatically when you power on the system, and you can adjust its level independently.

In contrast, the Sonos Arc Ultra uses innovative HeartMotion technology - a new approach to generating bass from the main unit itself. This technology allows for surprisingly deep bass without a separate subwoofer, though Sonos offers an optional sub for those wanting maximum impact. During testing, the Arc Ultra's integrated bass proved more than adequate for most content, though hardcore movie enthusiasts might still prefer a dedicated subwoofer.

Atmos Implementation

Both systems handle Dolby Atmos differently. The Polk uses physical upfiring speakers (drivers that point toward your ceiling) to create height effects. This traditional approach works well in rooms with flat ceilings between 7-14 feet high. The system's 3.1.2 configuration means you get left, center, and right channels, plus two height channels and the subwoofer.

The Sonos takes a more advanced approach, using sophisticated processing to create a virtual 9.1.4 soundstage. While it doesn't have physical upfiring drivers, its advanced processing creates convincing height effects through careful speaker positioning and acoustic manipulation. In practice, both approaches can be effective, though the Sonos generally creates a larger, more enveloping sound field.

Audio Processing and Customization

The technology behind how these systems process audio signals reveals significant differences in their capabilities. The Polk focuses on essential features like Voice Adjust technology, which helps make dialogue clearer by boosting specific frequencies. It offers basic sound modes for movies, music, and night listening.

The Sonos Arc Ultra represents a significant leap forward in processing capability. It includes room calibration technology that uses your smartphone's microphone to analyze how sound reflects in your space, then adjusts the audio output accordingly. This automatic tuning makes a noticeable difference in sound quality, especially in challenging room layouts.

Connectivity and Integration

Modern soundbars need to handle various input sources, and both systems include HDMI eARC (enhanced Audio Return Channel) connections. This latest standard allows for uncompressed Dolby Atmos audio to pass from your TV to the soundbar.

The Polk Signa S4 keeps things simple with HDMI eARC, optical input, and Bluetooth connectivity. This covers most users' needs, allowing you to connect to your TV and stream music from your phone.

The Sonos Arc Ultra offers more extensive connectivity options, including WiFi for high-quality streaming, AirPlay 2 for Apple devices, and the latest Bluetooth 5.3 standard. It can be part of a whole-home audio system, playing different music in different rooms or synchronizing playback throughout your house.

Real-World Performance

In practical use, both systems excel at their primary task - improving TV and movie sound. The Polk delivers clear dialogue and impressive Atmos effects for its price point. The included subwoofer provides satisfying bass for movies, though it can sometimes sound a bit boomy compared to more expensive systems.

The Sonos creates a notably larger soundstage with more precise placement of effects. Its advanced processing helps it adapt better to different room layouts, and the sound quality remains consistent at both low and high volumes. Music playback is particularly impressive on the Arc Ultra, with excellent stereo separation and detailed reproduction of complex recordings.

Value Consideration

Released in early 2022, the Polk Signa S4 has established itself as an excellent value proposition. It delivers true Dolby Atmos performance and includes a wireless subwoofer at a price point that's hard to beat. While it lacks some advanced features, it handles its core functions admirably.

The Sonos Arc Ultra, launched in late 2024, represents the latest in soundbar technology. Its higher price reflects its premium positioning, advanced processing capabilities, and integration with the wider Sonos ecosystem. The ability to expand the system later with additional Sonos speakers adds long-term value for those interested in whole-home audio.

How to Decide

The choice between these systems largely depends on your priorities and budget. Choose the Polk if:

• You want immediate full-range sound with included subwoofer
• Your budget is limited but you still want true Atmos performance
• You prefer simple setup and operation
• Movies and TV are your primary use case

The Sonos makes more sense if:

• You're planning to build a multi-room audio system
• You want maximum processing and customization options
• You value ecosystem integration and future expandability
• Music playback quality is as important as movie performance
• Your budget allows for a premium audio solution

Both systems represent significant improvements over basic TV speakers, but they target different segments of the market. The Polk offers excellent value for basic Atmos performance, while the Sonos provides a premium experience with greater flexibility and future expansion options.

For most users seeking to upgrade their TV audio, either system will provide a dramatic improvement. Your choice should align with your budget, room setup, and whether you plan to expand your audio system in the future.

Polk Audio Signa S4 Dolby Atmos Soundbar with Wireless Subwoofer Deals and Prices

Sonos Arc Ultra Dolby Atmos Soundbar Deals and Prices