Polk Audio Polk Signa S4 Dolby Atmos 3.1.2 Sound Bar with Wireless Subwoofer
By Polk Audio · Soundbars · Desk & Streaming Setup
- Sound bar 41.2 x 3.7 x 2.4 in (1046 x 95 x 60 mm)
- Inputs: 1x HDMI eARC, 1x optical, 1x 3.5 mm analog, Bluetooth, USB-A (firmware only)
- Low-profile wall-mountable design
Lowest price seen
$449.00
from $449.00 at Denon · Checked Oct 20, 2026
- Denon $449.00View at Denon
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Summary
A 3.1.2 Dolby Atmos sound bar with a wireless subwoofer, built for dialogue clarity and one-cable HDMI eARC setup.
Strengths
- Two physical up-firing height drivers produce a real overhead Atmos effect rather than a psychoacoustic imitation.
- Setup is one cable over HDMI eARC or optical, and both cables, a remote and a wall-mount kit are in the box.
- The wireless subwoofer connects on start-up and can be placed wherever the room allows.
- There is no subscription and no recurring cost beyond electricity.
Weaknesses
- No Wi-Fi: no Chromecast, AirPlay or smart-home control, so streaming is Bluetooth only.
- No rear speakers and no way to add them; surround content is downmixed to stereo.
- Height-driver volume cannot be adjusted independently.
- Low-bass thump is limited, and Consumer Reports found bass can turn boomy in Music mode.
- Status is shown only by LEDs behind the grille; there is no on-screen display.
- At 41-42 in long, the bar may not fit a small TV stand.
Verified specifications
| Model | Polk Audio Signa S4, polkaudio.com model 300443; released 2021. |
|---|---|
| Channels | 3.1.2 — left, center and right, a subwoofer and two up-firing height channels; 11 drivers total. |
| Dolby Atmos | certified, and it needs HDMI eARC between the bar and TV. |
| Sound bar drivers | 2 x 1 in tweeters, 2 x 4.7 x 1.6 in racetrack mids, 1 x 1 in full-range center and 2 x 2.6 in elevation drivers. |
| Subwoofer | 1 x 5.9 in down-firing woofer, wireless, auto-connecting on start-up. |
| Inputs | 1x HDMI eARC, 1x optical (TOSLINK) and 1x 3.5 mm analog; Bluetooth audio; USB-A for firmware updates only. |
| VoiceAdjust | Polk’s dialogue enhancement with three voice levels. |
| BassAdjust | blends bass across the bar and subwoofer. |
| Sound modes | Movie, Music and Night; Night lowers bass while raising VoiceAdjust. |
| Polk SmartBar | pre-programmed to work with most TV remotes over HDMI eARC. |
| Peak power | 410 W. |
| Dimensions | sound bar 41.2 x 3.7 x 2.4 in (1046 x 95 x 60 mm); subwoofer 7.9 x 12.9 x 11.0 in (200 x 328 x 280 mm). |
| Weight | the manual lists the bar at 6 lbs 6 oz (2.9 kg) and the subwoofer at 9 lbs 1 oz (4.1 kg). |
| Power | bar 40 W and subwoofer 40 W; bar standby 1.5 W and deep standby 0.3 W; subwoofer standby and deep standby 0.3 W; AC 100-240 V, 50/60 Hz. |
| Auto standby | the bar drops into standby after about 20 minutes with no operation and no audio; deep standby is toggled by holding VoiceAdjust 3 for about 5 seconds. |
| In the box | sound bar, subwoofer, remote, power cord, HDMI cable, optical cable, 2x AAA batteries, quick start guide, wall-mount template and spacers. |
| Warranty | Polk’s US page defers to the owner’s manual for legal terms; the exact length was not confirmed from the checked pages. |
Full research notes and sources
Dialogue and sound modes
Polk’s VoiceAdjust is a patented dialogue enhancement that combines a dedicated 1 in center channel with three adjustable voice levels; the owner’s manual documents Voice Adjust 1, 2 and 3 for movie dialogue and music vocals. CNET, Digital Trends, Tom’s Guide and WIRED all praise intelligibility, and Polk’s verified-buyer quotes echo it. Modes are Movie, Music and Night, with Night lowering bass while raising VoiceAdjust. BassAdjust blends bass between the bar and the subwoofer. RTINGS found dialogue reproduced clearly and accurately, with a slightly V-shaped sound that adds bass punch and treble brightness.
Atmos and surround limits
The bar carries two physical up-firing elevation drivers, so overhead effects come from real height speakers rather than the psychoacoustic height of the Sonos Beam Gen 2; Consumer Reports’ lab listening found Atmos imaging can extend almost directly overhead. The trade-off is that there is no rear surround: CNET and RTINGS note that surround content is downmixed to stereo and rear-originating sounds come from the front. Height-channel volume is not independently adjustable, and Consumer Reports rated sound quality “Fair”, with thin, grainy midrange and smeared treble on some material. A 61-page service manual is indexed online, which suggests repair documentation exists, though no service network was found.
Setup, inputs and power use
Setup is one cable: HDMI eARC for Atmos, optical or 3.5 mm analog for everything else, and both HDMI and optical cables are included. Polk SmartBar lets the bar respond to most TV remotes over eARC. Bluetooth covers streaming, but with no Wi-Fi there is no Chromecast, AirPlay or multi-room. The USB-A port is for firmware updates only, not media. The manual lists the bar at 40 W and the sub at 40 W, with the bar dropping to 1.5 W in standby and 0.3 W in deep standby; in deep standby, auto-on from optical, AUX or Bluetooth stops working. CHOICE measured standby energy at A$4.50 a year for the Australian model (2022).
At Polk’s own $449 US price (2026-10-20), with price matching and 30-day returns, the S4 is fair but no longer remarkable; CNET’s 2026 guide still lists it as a recommended Atmos bar under $450. The catch is that Polk’s refreshed S4D, with the same features and performance per RTINGS, is listed at $299, and a refurbished S4 at $289, so paying $449 for the S4 specifically is hard to justify. At street prices near $399 or below, Tom’s Guide’s 2025 checks treated it as one of the better values in budget Atmos. One r/Soundbars owner reported paying $160 for an S4D on a student discount, an anecdote rather than a price anchor.
Is it worth it?
Buy the Signa S4 for dialogue clarity, simple eARC setup and true up-firing height effects. Skip it if you want Wi-Fi streaming, rear surrounds or deep bass rumble, or if the S4D is within reach at $299.
Sources
Manufacturer:
- Signa S4 | Polk Audio (US product page)
- Signa S4 Info Sheet (Polk PDF)
- Signa S4 Owner’s Manual (Polk PDF)
- Polk Audio Warranty | US
Independent reviews:
Owner reports:
