The Polk Audio Signa S4 is a 3.1.2 setup released in 2021. It's the higher-end bar in Polk's Signa Series, and unlike the Polk Audio Signa S2, it supports Dolby Atmos content. Its slightly V-shaped sound adds extra punch in the bass and brightness in the treble to your favorite music. Dialogue still reproduces very clearly, and there's even an adjustable dialogue enhancement feature that lets you control how loud voices sound in the mix. However, it lacks a thumpy low-bass, so you don't feel the excitement in action movies and bass-heavy music.
Our Verdict
The Polk Audio Signa S4 is fair for mixed usage. Its slightly V-shaped sound adds extra punch in the bass and brightness in the treble to your favorite music. Dialogue reproduces quite clearly and accurately, too, and its adjustable dialogue enhancement feature is handy for listening to TV shows and podcasts. Also, it supports Dolby Atmos content. However, the lack of low-bass takes away from the immersive feeling in action movies, and its surround sound performance isn't the most impressive.
- Bass adjustment feature.
- Adjustable dialogue enhancement feature.
- Lacks low-bass.
- Downmixes surround sound into stereo.
The Polk Audio Signa S4 is satisfactory for dialogue-centric content like TV shows and documentaries. It's a 3.1.2 setup with a discrete center channel that helps anchor voices to a pinpoint location in the soundstage. You can even make voices more clear and crisp using its adjustable dialogue enhancement feature - which Polk calls VoiceAdjust. The Night Mode tool is handy, too, since it reduces the bass and increases the volume of the voices to help you hear dialogue clearly at night.
- Adjustable dialogue enhancement feature.
- No Wi-Fi, Chromecast, or AirPlay support.
The Polk Audio Signa S4 is fair for music. Out-of-the-box, it has a slightly V-shaped sound profile that adds a little extra punch in the bass and some brightness in the treble range. Vocals and lead instruments are clearly and accurately reproduced, and higher-pitched instruments sparkle with brightness. You can customize its sound a bit with its bass adjustment feature. However, it can't reproduce the deep thump and rumble in the low-bass found in bass-heavy genres like hip-hop and EDM.
- Bass adjustment feature.
- Bluetooth-compatible.
- Lacks low-bass.
- No treble adjustment.
The Polk Audio Signa S4 is okay for movies. It supports Dolby Atmos content with two up-firing drivers built into the bar itself. The performance is pretty good given its price point, but you notice the lack of low-bass in action-heavy scenes. It can also playback surround sound content like Dolby Digital, but the performance isn't the best. Without dedicated surround channels, it has to downmix this content into stereo to play it.
- Bass adjustment feature.
- Adjustable dialogue enhancement feature.
- Lacks low-bass.
- Downmixes surround sound into stereo.
Changelog
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Updated May 12, 2025:
We've added the Polk Audio Signa S4D as a variant in the 'Differences Between Variants' box of this review.
- Updated Jan 29, 2024: Updated text in Stereo Dynamics, Audio Latency: ARC, and Audio Latency: Optical boxes with new methodology from TBU 1.3.
- Updated Jan 29, 2024: We've converted this review to Test Bench Update 1.3. If applicable, we've retested stereo sound based on the manufacturer's recommendations. Additionally, we've expanded our audio latency tests to the following boxes: Audio Latency: ARC, Audio Latency: HDMI In, and Audio Latency: Optical. You can see the full changelog here.
- Updated Sep 01, 2023: Added market comparison with the Polk Audio Magnifi Max AX SR in the Style - Satellites box.
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Differences Between Sizes And Variants
The Polk S4 is available in Black. You can see the label for the bar here. There's also the Polk Audio Signa S4D variant, which features a design refresh, with no change to the features and performance.
If you come across another version of this soundbar, let us know in the comments, and we'll update the review.
Popular Soundbar Comparisons
The Polk Audio Signa S4 is a 3.1.2 setup that offers a more affordable alternative to other Atmos bars on the market. Its Atmos performance is comparable to similarly-priced bars like the Sonos Beam (Gen 2), but it doesn't offer the same immersive sound as more premium setups. There's also a lack of low-bass that takes away from the thump and rumble in movie scores and action-filled scenes, which is a bit unfortunate. If you're on a budget, it's still a fairly versatile bar.
See also our recommendations for the best soundbars under $500, the best Dolby Atmos soundbars, and the best soundbars.
The Sonos Beam (Gen 2) is better than the Polk Audio Signa S4. The Sonos is a 5.0 setup with a small, compact design and is ideal if you don't have a lot of space. Despite its small size, it has better soundstage and surround performances than the Polk. It also has additional features, like room correction and built-in voice assistant support.
The JBL Bar 5.1 Surround is a bit better for mixed usage than the Polk Audio Signa S4. The JBL is a 5.1 setup with a better surrounds performance. It can reproduce a more extended low-bass, and it also comes with more sound enhancement features, including room correction. That said, the Polk is still a pretty versatile 3.1.2 setup. It has a better soundstage than the JBL, and it even supports Dolby Atmos content.
The Polk Audio Magnifi Max AX SR is better than the Polk Audio Signa S4. The Max AX SR is a better-built soundbar with discrete satellites to improve its surround sound. It gets louder, too, and it offers a more extended low-bass. You have more wireless playback options, too.
Depending on your listening habits, you may prefer either the Polk Audio MagniFi MAX SR or the Polk Audio Signa S4. The MAX SR is a 5.1 setup that comes with dedicated satellites, and it has a better surround sound performance. However, it doesn't support Dolby Atmos content like the Signa S4. Also, the MAX SR reproduces a lot of compression and distortion, especially in the bass range, that affects the sound of your audio.
Test Results
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