Polk Signa S4 review

Sound

The S4 gives the center channel its own driver, which provides a physical home for dialogue rather than relying entirely on the left and right speakers. The separate subwoofer handles lower frequencies, allowing its position to be adjusted independently of the television. Both parts need a nearby power outlet.

RTINGS found clear dialogue and a mildly emphasized bass-and-treble balance, but limited deepest-bass output.¹ That is a useful distinction: a system can sound lively without reproducing the lowest movie effects convincingly. The presence of a separate subwoofer does not settle that question by itself.

Tom’s Guide heard substantial impact in Movie mode during its office listening, but also found that stronger bass could obscure softer speech.² Those observations support adjusting the balance for the room and program. More bass is not automatically the most useful setting.

Dolby Atmos

The upward-facing pair gives height information a physical playback path. Keep the top of the bar clear so that the TV, a shelf or a cabinet does not obstruct it. The result still depends on the room and listening position; a channel label cannot guarantee a precise overhead effect at every seat.

The system has no speakers behind the listener. RTINGS found conventional surround playback limited by downmixing into the front presentation.¹ Atmos support should therefore be understood alongside the S4’s actual speaker layout, rather than as a promise of complete room coverage.

Polk confirms that its wireless rear speakers cannot be added to the S4. Buy it for the system it already is. If a future pair of rear speakers is part of the plan, choose an expandable range before spending money on this one.

Dialogue and Controls

VoiceAdjust provides three levels of vocal emphasis. Compare them on ordinary television at the volume normally used, rather than choosing the strongest setting during setup and leaving it there. Tom’s Guide preferred the least aggressive level in its test and found the higher settings reduced bass presence.²

Night mode compresses the difference between quieter and louder sounds. It can make late viewing easier at a restrained volume, although it cannot prevent all sound from travelling to another room. Movie and Music modes offer broader changes in presentation.

A supplied remote and top-panel buttons provide the main controls. Status LEDs indicate inputs and modes without a text display. HDMI control can hand routine volume and power to a compatible TV remote, while the Polk remote remains useful for the sound settings.

Connectivity

The HDMI connection returns audio from the television; it is not an input for a console or disc player. Connect those sources to the TV, then verify its audio-output and passthrough settings. The TV becomes an important part of the audio path.

Use HDMI eARC for the broadest supported Dolby-format connection. The manual lists Atmos, TrueHD, Dolby Digital Plus, Dolby Digital and linear PCM. DTS formats are not supported, so a source with a DTS soundtrack needs an appropriate conversion or another audio track. Optical remains useful for simpler TV connections, but it is not an Atmos route.

The included HDMI and optical cables cover the main television options. An analog input offers another connection for a suitable external source, but it does not include a turntable phono stage or turn the bar into a video-switching hub.

Music Playback

Bluetooth provides a direct music connection from a phone or tablet. There are no built-in Wi-Fi services such as AirPlay or Google Cast, and no multiroom network platform to configure. This suits occasional music playback more than a household planning coordinated speakers throughout the home.

The current owner’s manual also describes automatic music playback from a USB drive, activated by holding the Music button. Product sheets still describe USB as an update port, and the supported music-file types are not established in the documentation reviewed. Treat it as a documented secondary option rather than the main reason to buy.

For a permanent music source, the analog input may be more straightforward. A streaming device connected to the television can also supply audio, but that arrangement depends on the TV’s behavior rather than a streaming service built into the S4.

Design and Installation

The bar is low but fairly wide. Measure the surface between the TV feet as well as the clearance below the picture. A low chassis is helpful only if the feet, remote sensor and upward-facing drivers can all remain unobstructed.

Keyhole mounting is supported, with a template and spacers supplied. The manual varies the required gap below a wall-mounted TV according to how far the screen projects above the bar. Follow that diagram rather than mounting the two products tightly together for appearance alone. Suitable wall fixings are still required.

The S4D is an online-exclusive finish, not a separate performance generation. RTINGS identifies the same feature set without claiming a second listening test.¹ Polk’s US powered-soundbar warranty policy lists one year for amplifiers and three for speakers through authorized sellers; check the included terms for the purchased unit.

Alternatives

The Signa numbering is not a simple replacement ladder: other Signa models remain in Polk’s range with different feature priorities. The useful question is whether this specific combination of a center speaker, upfiring drivers and a supplied subwoofer addresses a limitation in the current setup. There is no reason to replace a satisfactory earlier bar merely to move to a higher model number.

The MagniFi Mini AX offers Wi-Fi music and optional SR2 rear speakers in a much shorter, slightly taller front unit. It does not have the S4’s physical upfiring drivers. Consider the Mini AX for its network functions and expansion path, or the S4 for a fixed system with dedicated height drivers and simpler controls.

Verdict

The Signa S4 is a focused TV sound system with useful dialogue controls and a modest Atmos hardware arrangement. Its simplicity works when a bar and subwoofer are all the room will need. Choose another family if Wi-Fi music, rear expansion or source switching is likely to become important.