Amazon Fire TV Soundbar Plus vs. LG S40T: Which Soundbar Wins for Your Home Theater?

If you've ever tried watching an action movie and found yourself constantly adjusting the volume—cranking it up to hear dialogue, then quickly turning it down when explosions blast through your living room—you know exactly why soundbars have become essential home theater components. These sleek audio solutions promise to fix the biggest problem with modern TVs: terrible built-in speakers.

Today we're comparing two popular options that take very different approaches to upgrading your TV audio: the Amazon Fire TV Soundbar Plus with Subwoofer and the LG S40T 2.1 Channel Soundbar. While both aim to improve your viewing experience, they serve different needs and budgets, making the choice between them more nuanced than you might expect.

Understanding What Makes a Good Soundbar

Before diving into specifics, let's establish what separates great soundbars from mediocre ones. The most important factor is channel configuration—this refers to how many separate audio channels the system can produce. A 2.1 system has left and right channels plus a subwoofer (the ".1" represents the dedicated bass channel). A 3.1 system adds a center channel specifically for dialogue, while 5.1 includes rear speakers for true surround sound.

Audio format support matters tremendously for home theater use. Basic soundbars handle standard Dolby Digital, but premium models support advanced formats like Dolby Atmos, which creates three-dimensional sound by bouncing audio off your ceiling. Connectivity options determine how easily the soundbar integrates with your existing setup, while smart features can either simplify daily use or add unnecessary complexity, depending on your preferences.

The physical design isn't just about looks—soundbar length should roughly match your TV width for optimal sound dispersion, and the height matters if you're mounting your TV close to a cabinet.

Meet the Contenders

Amazon Fire TV Soundbar Plus: The Expandable Powerhouse

Released in 2023 as Amazon's second-generation soundbar, the Amazon Fire TV Soundbar Plus represents a significant step up from basic TV audio. This system comes with a 3.1 channel soundbar and wireless subwoofer, but its real strength lies in expandability—you can add rear satellite speakers to create a full 5.1 surround system.

At 37 inches long, it's designed for larger TVs (50 inches and up) and includes support for premium audio formats like Dolby Atmos and Dolby TrueHD. However, there's an important caveat: the Dolby Atmos implementation is virtualized, meaning it uses digital processing to simulate overhead sound rather than physical speakers firing upward.

LG S40T: The Smart Integration Champion

The LG S40T, available since 2024, takes a different approach by focusing on seamless integration and intelligent features. This 2.1 system (stereo plus subwoofer) emphasizes ease of use and smart processing over raw channel count.

What sets the LG S40T apart is its AI Sound Pro technology, which automatically analyzes whatever you're watching and adjusts the audio profile accordingly. It also includes several LG-specific features that create compelling value if you own an LG TV.

Audio Performance: Where the Differences Really Matter

Format Support and Processing Power

Here's where these soundbars reveal their different philosophies. The Amazon Fire TV Soundbar Plus supports lossless audio formats like Dolby TrueHD—these maintain the original studio-quality audio without compression, crucial for Blu-ray movies and high-end streaming content. It also handles DTS:X, another object-based surround format that competes with Dolby Atmos.

The virtualized Dolby Atmos deserves explanation. Traditional Atmos systems use speakers mounted in or on your ceiling to create overhead effects. The Amazon Fire TV Soundbar Plus instead uses sophisticated digital processing to bounce sound off your ceiling, simulating that three-dimensional effect. While not as precise as dedicated overhead speakers, this approach works surprisingly well in rooms with standard 8-9 foot ceilings.

In contrast, the LG S40T sticks with standard Dolby Digital and DTS Digital—compressed formats that work fine for broadcast TV and most streaming content but lack the dynamic range and precision of lossless formats. However, its AI Sound Pro partially compensates by actively analyzing content and applying optimal processing in real-time.

Dialogue Clarity: The Make-or-Break Feature

Based on our research into user experiences and expert reviews, dialogue performance reveals interesting differences between these systems. The Amazon Fire TV Soundbar Plus benefits from its dedicated center channel, which handles dialogue separately from music and effects. This discrete channel separation means voices stay clear even during complex action sequences.

Users consistently report that the system's dialogue enhancement feature works well, though some note that very deep male voices can sound slightly thin. The elevated bass response from the subwoofer occasionally overwhelms speech during particularly explosive scenes, but the dialogue enhancer button on the remote quickly corrects this.

The LG S40T takes a different approach without a dedicated center channel. Instead, it relies on phantom center imaging—using the left and right speakers to create the illusion of centered dialogue. This works adequately for most content, but voices can wander slightly during intense scenes where multiple audio elements compete for attention.

Bass Response and Subwoofer Performance

Subwoofer quality often separates good soundbars from great ones. The Amazon Fire TV Soundbar Plus includes a wireless subwoofer that provides substantial low-frequency extension, particularly effective for movie sound effects. However, based on expert analysis, the subwoofer exhibits what audio professionals call a "one-note" characteristic—it emphasizes deep bass but lacks emphasis in the crucial mid-bass range (roughly 80-200Hz) where many movie effects and music fundamentals live.

This means explosions and thunder sound impressive, but the subwoofer might not add much warmth to music or the full-bodied impact you'd get from more expensive systems. At higher volumes, the bass can become "flappy"—a technical term describing when the subwoofer's driver moves too much, creating distorted, loose-sounding bass.

The LG S40T's 35W subwoofer provides more modest but potentially more accurate bass response. With 300W total system power, it's designed for balanced performance across different content types rather than maximum impact. Users report better integration between the subwoofer and main speakers, creating more cohesive sound overall.

Soundstage and Imaging

Soundstage refers to how wide and deep the audio image appears to extend beyond the physical speakers. The Amazon Fire TV Soundbar Plus creates a soundstage that extends slightly wider than the bar itself, with good focus as audio elements pan from left to right. However, expert analysis reveals gaps in the stereo image for sounds positioned between the left and right bounds of the bar—a limitation of its driver arrangement.

When expanded to 5.1 with rear speakers, the Amazon system provides what reviews describe as "lateral 360-degree surround"—excellent side-to-side immersion, though the virtualized height effects don't match systems with physical overhead speakers.

The LG S40T creates a more compact but potentially more coherent soundstage. Its 2.1 configuration focuses on solid stereo imaging rather than trying to simulate surround effects, which can actually sound more natural for music and TV content.

Smart Features and Integration: Where Modern Soundbars Shine

Amazon's Fire TV Integration

Despite carrying the "Fire TV" name, the Amazon Fire TV Soundbar Plus doesn't include built-in streaming capabilities or Alexa voice control. Instead, it offers deeper integration when connected to compatible Fire TV devices, allowing more granular audio control through your TV's settings menu.

This integration includes the ability to use your Fire TV remote for basic soundbar functions and access to additional audio fine-tuning options. However, there's no dedicated smartphone app, which limits customization compared to more connected alternatives.

The system does include comprehensive manual controls via its included remote, with independent bass and treble adjustment (on a 1-9 scale) and multiple EQ presets: Movie, Music, Sports, and Night modes. The Night mode is particularly useful, compressing dynamic range so loud effects don't wake sleeping family members while keeping dialogue audible.

LG's Smart Ecosystem Advantages

The LG S40T truly shines when paired with LG TVs through several exclusive features. WOW Interface provides on-screen soundbar controls directly through your TV's menu system, eliminating the need to juggle multiple remotes. WOW Orchestra allows your TV's built-in speakers to work alongside the soundbar, creating a larger, more enveloping sound field.

The LG Soundbar App offers comprehensive customization through your smartphone, including a 3-band equalizer for bass, mid-range, and treble adjustment. This level of control surpasses what the Amazon system provides, especially for users who enjoy tweaking their audio settings.

AI Sound Pro represents LG's most interesting innovation. This feature continuously analyzes your content—whether it's a news broadcast, action movie, or music video—and automatically applies optimal audio processing. While the effectiveness varies depending on content quality and personal preferences, users report noticeable improvements in dialogue clarity and overall balance.

Value and Practical Considerations

Pricing and Performance Value

At the time of writing, these soundbars occupy different value tiers, with the Amazon Fire TV Soundbar Plus positioned as the more premium option. This higher cost reflects its 3.1 channel configuration, premium audio format support, and expansion capabilities.

The LG S40T offers compelling value in the mid-range category, delivering sophisticated smart features and solid performance at a more accessible price point. For LG TV owners specifically, the integration features provide additional value that narrows the effective price gap.

Setup and Daily Use

Both systems prioritize easy setup, but with different approaches. The Amazon Fire TV Soundbar Plus comes with its subwoofer pre-paired—simply plug everything in and power up. However, the lack of a smartphone app means all adjustments happen via the physical remote, which some users find less convenient in 2024.

The LG S40T also features plug-and-play setup, but its smartphone app and TV integration provide more flexible control options. The AI processing means less manual adjustment for optimal sound, appealing to users who prefer "set and forget" operation.

Room Size and TV Compatibility

Physical compatibility matters more than many buyers consider. The Amazon Fire TV Soundbar Plus measures 37 inches long, making it ideal for 50-65 inch TVs but potentially overwhelming smaller setups. Its more powerful drivers and subwoofer suit larger rooms where you need to fill more space with sound.

The LG S40T's 28.4-inch length works well with smaller TVs and rooms, while its more controlled output prevents overwhelming compact spaces. The compact design also offers more flexibility for placement in cabinets or wall-mounting scenarios.

Home Theater Performance: The Real-World Test

Movie Watching Experience

For serious movie watching, the Amazon Fire TV Soundbar Plus provides clear advantages. The lossless audio format support means you'll hear Blu-ray movies and premium streaming content as intended by filmmakers. The dedicated center channel keeps dialogue clear during complex soundtracks, while the expandability to 5.1 surround creates genuine home theater immersion.

However, the virtualized Dolby Atmos, while impressive for the price point, lacks the precision of systems with physical height speakers. Overhead effects like helicopters or rain sound processed rather than natural, though this may not bother casual viewers.

The LG S40T excels with everyday TV content, where its AI processing and balanced sound signature provide consistently enjoyable audio. The more modest bass response actually works better for mixed content viewing, where overpowering subwoofers can dominate dialogue and music.

Music Performance

Neither soundbar primarily targets music enthusiasts, but their different approaches create distinct listening experiences. The Amazon system's slightly excited sound signature with emphasized bass can make pop and electronic music sound engaging, though the "one-note" subwoofer character limits its effectiveness with acoustic music.

The LG S40T's more balanced approach and superior app-based EQ controls make it more versatile for music listening. The AI processing adapts well to different musical genres, automatically adjusting the sound profile for optimal performance.

Who Should Choose Which Soundbar?

Choose the Amazon Fire TV Soundbar Plus If:

You're building a proper home theater setup and prioritize cinematic audio quality. The premium format support and expansion capabilities make this system ideal for movie enthusiasts willing to invest in better sound. Fire TV device owners will appreciate the seamless integration, while the larger soundbar suits rooms with 50-inch or larger TVs.

The Amazon system also makes sense if you plan to gradually build toward a full 5.1 surround system. Starting with the soundbar and subwoofer gives you excellent performance immediately, with the option to add rear speakers when budget allows.

Choose the LG S40T If:

You own an LG TV and want the best possible integration experience. The exclusive features like WOW Orchestra and WOW Interface provide value that competitors can't match. The AI processing and comprehensive app controls suit users who want intelligent, adaptable audio without manual tweaking.

The LG S40T also works well for smaller rooms, mixed content viewing, and situations where a more compact, balanced sound signature fits better than powerful, cinematic audio. The lower price point makes it accessible for budget-conscious upgraders who still want smart features and solid performance.

The Bottom Line

These soundbars represent two valid but different approaches to upgrading TV audio. The Amazon Fire TV Soundbar Plus prioritizes raw audio performance and future expandability, making it the better choice for dedicated home theater use despite some limitations in its subwoofer design and smart features.

The LG S40T focuses on intelligent processing and seamless integration, delivering exceptional value for everyday use, especially within LG's ecosystem. Its more modest specifications don't prevent it from providing satisfying audio performance for most users.

Your decision should align with your viewing habits, existing equipment, room size, and whether you prioritize maximum audio fidelity or intelligent, adaptive features. Both soundbars represent significant upgrades over TV speakers, but choosing the right one depends on understanding which approach better matches your specific needs and preferences.

At the time of writing, both systems offer compelling value in their respective categories, though the rapid pace of soundbar innovation means new competitors regularly enter the market. Consider your long-term needs and integration requirements when making this investment in your home entertainment experience.

Amazon Fire TV Soundbar Plus Subwoofer Deals and Prices

LG S40T 2.1 Channel Soundbar Deals and Prices