In this Polk Signa S2 vs Yamaha YAS-108 comparison guide, upgrading your TV sound does not have to cost a fortune. The Polk Audio Signa S2 and the Yamaha YAS-108 are two popular budget soundbars that boost movie night in distinct ways.
Updated October 2026: Both bars here promise bass without a big system - they just deliver it differently. The Signa S2 pairs its bar with a separate wireless subwoofer; the YAS-108 builds its bass into the bar itself. That single design choice decides the bass depth, the floor space, and the setup effort. This update adds the disclosure this article was missing, plus the separate-versus-built-in verdict below.
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The Polk Audio Signa S2 is a 2.1 setup. It comes with a separate wireless sub for deep bass. The Yamaha YAS-108 is a single soundbar with built-in subwoofers and 3D virtual surround audio.
This guide helps TV watchers, movie lovers, and gamers choose between the Polk Audio Signa S2 vs Yamaha YAS-108. You will learn how they differ in bass, voice clarity, ports, and room setup.
Key Differences at a Glance
The main difference between the Polk Audio Signa S2 and the Yamaha YAS-108 is the bass setup. The Polk Audio Signa S2 uses an external wireless subwoofer for strong room-shaking low notes. The Yamaha YAS-108 uses built-in subwoofers to save floor space while offering 3D surround sound with DTS Virtual:X technology.
The Polk Audio Signa S2 is better for deep movie bass. The Yamaha YAS-108 is better for compact rooms and wide surround sound.
Polk Audio Signa S2 Review
The Polk Audio Signa S2 is a low-profile soundbar paired with a wireless subwoofer. It sits low on your TV stand so it does not block your TV remote sensor. The soundbar is wrapped in a soft black fabric top and front grill.
Setting up the Polk Audio Signa S2 is quick and simple. You plug the soundbar into your TV with an optical cable or an HDMI ARC cable. The wireless subwoofer connects automatically when you turn on the power.
The sound profile is tuned for rich movie tracks and clear dialogue. Polk uses VoiceAdjust technology to boost vocal tracks. You can raise actor voices without raising the background noise. The external subwoofer adds deep low notes that make action scenes feel powerful.
What I Like
- External wireless subwoofer delivers deep bass for big action movies.
- Low profile design fits under almost any flat panel TV setup.
- Polk VoiceAdjust helps you hear dialogue clearly at low night volumes.
- Includes both HDMI ARC and optical audio cables in the box.
What Could Be Better
- Lacks HDMI passthrough for extra media player inputs.
- Basic remote control feels small and easy to lose between cushions.
Who Should Buy the Polk Audio Signa S2?
The Polk Audio Signa S2 is ideal for movie lovers who want deep bass rumble without complex wires. It fits well in medium and large living rooms.
Who Should Avoid the Polk Audio Signa S2?
Avoid the Polk Audio Signa S2 if you do not have floor space for an extra subwoofer box.
Check Polk Audio Signa S2 Price on Amazon →
Yamaha YAS-108 Review
The Yamaha YAS-108 is a sleek, single-bar solution designed for clean setups. It features a slim body with rounded ends and built-in keyholes for easy wall mounting. It does not require a separate subwoofer box on your floor.
Instead of an extra box, the Yamaha YAS-108 uses two built-in subwoofers with bass reflex ports. It also features DTS Virtual:X. This mode creates a 3D surround sound effect without needing extra wall speakers.
Connectivity is a major strength for the Yamaha YAS-108. It includes an HDMI input and an HDMI output with 4K pass-through. You can plug a streaming stick or game console straight into the bar. It also features multi-device Bluetooth so you can pair two phones at once.
What I Like
- Single bar design frees up floor space by eliminating the sub box.
- DTS Virtual:X creates a wide surround sound feel across the room.
- HDMI passthrough supports 4K HDR video signals from streaming devices.
- Subwoofer output port allows adding a powered sub later if desired.
What Could Be Better
- Internal subwoofers cannot match the deep bass of a standalone sub box.
- Touch control buttons on top can be hard to see in dim rooms.
Who Should Buy the Yamaha YAS-108?
The Yamaha YAS-108 is ideal for apartment dwellers, bedroom setups, or anyone who wants a clean look with no extra boxes on the floor.
Who Should Avoid the Yamaha YAS-108?
Avoid the Yamaha YAS-108 if you want heavy bass impact for huge action blockbusters.
Check Yamaha YAS-108 Price on Amazon →
Detailed Comparison
Bass and Low-End Impact
The most noticeable difference comes from how each soundbar handles low notes.
The Polk Audio Signa S2 includes a dedicated wireless subwoofer box. This 5.25-inch woofer pushes real air into the room. It gives deep bass response during explosions, drum beats, and heavy music tracks.
The Yamaha YAS-108 uses two 3-inch internal subwoofers. It uses bass extension processing to sound fuller. While it sounds impressive for its size, it cannot play as low or loud as a standalone cabinet.
For maximum bass impact, the Polk Audio Signa S2 is the clear winner.
Surround Sound and Soundstage
Creating a wide sound image makes movies feel more immersive.
The Yamaha YAS-108 features DTS Virtual:X 3D surround sound processing. This technology simulates height and surround channels. It makes audio feel like it comes from above and around your head. It creates a wide soundstage for movies and video games.
The Polk Audio Signa S2 focuses on traditional stereo sound decoding with Dolby Digital. It creates a natural front soundstage, but it does not simulate overhead audio height.
The Yamaha YAS-108 creates a broader 3D sound field for movie nights.
Voice Clarity and Dialogue
Clear voice reproduction is vital when watching news, sports, or dialogue-heavy TV shows.
Polk uses its proprietary VoiceAdjust technology in the Polk Audio Signa S2. It provides three explicit voice level modes on the remote control. You can boost vocal clarity independently from the main volume.
Yamaha uses Clear Voice technology in the Yamaha YAS-108. It boosts dialogue frequency bands with a single button press. It works well, but it gives you less adjustment control than the Polk system.
The Polk Audio Signa S2 offers slightly better voice level fine-tuning.
Ports and TV Connectivity
Connecting your media devices easily reduces cord clutter behind your entertainment center.
The Yamaha YAS-108 includes both an HDMI input port and an HDMI ARC output port. It supports 4K HDR passthrough. You can connect a gaming console directly to the soundbar and pass video to your TV. It also offers dual-device Bluetooth switching.
The Polk Audio Signa S2 has one HDMI ARC port, one optical digital input, and one 3.5mm aux input. It lacks an HDMI passthrough input. You must plug your game consoles directly into your TV instead.
The Yamaha YAS-108 offers more flexible input connections.
Design and Space Requirements
Placement flexibility depends heavily on your living room layout.
The Polk Audio Signa S2 bar is very slim at just 2 inches tall. It glides under low-clearance TV stands easily. However, you must find a spot on your floor for the wireless sub near a power outlet.
The Yamaha YAS-108 is a single-unit design. You place it on your TV stand or hang it on the wall using its built-in keyholes. There are no extra floor boxes or secondary power cables.
The Yamaha YAS-108 is easier to fit into small rooms or minimalist spaces.
Real-World Buying Scenarios
Choose the Polk Audio Signa S2 if:
- You love action movies and want real bass rumble from a dedicated sub.
- You have floor space next to your TV console for a wireless sub box.
- You frequently struggle to hear dialogue during quiet movie scenes.
Choose the Yamaha YAS-108 if:
- You live in an apartment or bedroom where floor space is limited.
- You want 3D virtual surround sound for gaming and movies.
- You need an HDMI input with 4K passthrough for a streaming stick or console.
Market Positioning
The Polk Audio Signa S2 targets buyers who want a classic 2.1 home theater sound system at an accessible entry price. It focuses on physical bass hardware and simple TV integration.
The Yamaha YAS-108 targets space-conscious buyers who prefer an all-in-one package. It focuses on smart audio processing and connectivity features like DTS Virtual:X and HDMI passthrough.
Is It Worth Buying?
Both of these budget soundbars offer a huge upgrade over built-in TV speakers. TV speakers produce flat audio with weak bass and muffled dialogue.
The Polk Audio Signa S2 is worth buying if low-end power is your top priority. The included wireless sub delivers impact that single soundbars simply cannot replicate.
The Yamaha YAS-108 is worth buying if space savings and extra ports matter more to you. Its built-in subwoofers sound surprisingly full, and you can always add an external sub later via its dedicated sub output.
Quick Decision Guide
- For maximum bass: Pick the Polk Audio Signa S2.
- For small rooms: Pick the Yamaha YAS-108.
- For dialogue adjustment: Pick the Polk Audio Signa S2.
- For 3D virtual surround: Pick the Yamaha YAS-108.
- For 4K HDMI passthrough: Pick the Yamaha YAS-108.
2026 Check: Separate Sub vs Built-In Bass - The Space Trade
The Signa S2’s separate sub is the bass advantage - and the space cost. A dedicated subwoofer placed on the floor moves more air than any drivers squeezed into a bar, so movie bass and music low-end land with real weight. The price is floor space, a second box to position, and a corner that actually suits it - a sub shoved behind furniture in a tiny room will not deliver what the spec sheet promises.
The YAS-108’s built-in bass is the tidy-room advantage. Everything in one bar means nothing to pair, nothing to place, and nothing for a small apartment to trip over. The bass will not reach as deep as a separate sub, but for TV dialogue, everyday viewing, and smaller rooms, the cleaner setup often matters more than the last octave of low end - and the article’s own voice-clarity comparison above is where the Yamaha makes its case.
Decide by room, then by ports. Large or open living room with floor space to spare: separate sub. Small room, bedroom, or a setup where a second box is a non-starter: built-in bass. Either way, check the ports against your TV before buying - the two bars differ on connectivity, and the best-sounding bar is useless on the wrong input. For the single-bar alternative with no sub at all, see our Signa S2 vs Bose Solo 5 comparison.
Final Verdict
Choosing between the Polk Audio Signa S2 vs Yamaha YAS-108 comes down to your space and bass preference.
The Polk Audio Signa S2 delivers deep bass impact thanks to its separate wireless subwoofer. Its VoiceAdjust feature keeps dialogue crisp during late-night viewing. It is the best choice for movie lovers with enough room for a subwoofer box.
The Yamaha YAS-108 is an all-in-one soundbar that saves floor space. Its built-in subwoofers and DTS Virtual:X 3D sound produce rich room-filling audio. Its 4K HDMI passthrough input gives you flexible wiring options. It is the best pick for compact setups, apartments, and clean wall-mounted installations.
For deep bass, buy the Polk Audio Signa S2. For a clean, space-saving design, buy the Yamaha YAS-108.
FAQ
Does the Polk Audio Signa S2 need a wire to connect to the subwoofer?
No. The subwoofer for the Polk Audio Signa S2 connects wirelessly to the main soundbar. You only need to plug the subwoofer into an electrical wall outlet.
Can you add a subwoofer to the Yamaha YAS-108?
Yes. The Yamaha YAS-108 includes a dedicated subwoofer output port. You can connect a separate powered subwoofer using a RCA sub cable if you want deeper bass later.
Will these soundbars work with my current TV remote?
Yes. Both the Polk Audio Signa S2 and Yamaha YAS-108 support HDMI ARC. When connected via HDMI ARC, your TV remote will control the soundbar power and volume automatically.
Which soundbar is better for small apartment rooms?
The Yamaha YAS-108 is better for small apartments. It combines built-in subwoofers into a single bar, saving floor space and preventing excessive low-end vibration through shared walls.
Do these soundbars support Bluetooth music streaming from a phone?
Yes. Both the Polk Audio Signa S2 and Yamaha YAS-108 feature built-in Bluetooth. You can stream music directly from your smartphone, tablet, or laptop.