LG S40T vs Denon DHT-S517: Finding the Right Soundbar for Your Budget and Needs

If you've ever found yourself cranking up the TV volume just to understand what the characters are saying, or felt like action scenes lack the punch they should have, you're not alone. Modern TVs, despite their stunning visuals, often have terrible built-in speakers. That's where soundbars come in – they're designed to solve these exact problems without the complexity of a full surround sound system.

Today, we're comparing two soundbars that take very different approaches to improving your audio experience: the budget-friendly LG S40T 2.1 Channel Soundbar at $156 and the more premium Denon DHT-S517 Soundbar with Wireless Subwoofer at $302. While both will dramatically improve your TV's audio, they're aimed at different users with different priorities.

Understanding What Makes a Good Soundbar

Before diving into the specifics, let's talk about what you should actually care about when shopping for a soundbar. The channel configuration – those numbers like 2.1 or 3.1.2 – tells you how many speakers are working together. The first number represents left and right speakers, the second is the subwoofer (the ".1"), and any third number indicates height or surround channels.

Power output, measured in watts, affects how loud your system can get and how well it handles dynamic scenes – think quiet dialogue followed by explosive action sequences. Connectivity options determine how easily the soundbar integrates with your existing setup, while audio format support dictates whether you can take advantage of advanced surround sound technologies.

Room size matching is crucial but often overlooked. A powerful soundbar in a small room can overwhelm, while an underpowered one in a large space will leave you wanting more. Finally, the price-to-performance ratio helps you determine if you're getting good value for your money.

The Contenders: Different Philosophies, Different Strengths

The LG S40T, released in early 2024, represents LG's approach to delivering solid audio performance without breaking the bank. It's a 2.1-channel system, meaning you get left and right speakers in the main bar plus a separate wireless subwoofer for bass. With 300W of total power (100W from the soundbar, 200W from the subwoofer), it focuses on delivering the fundamentals really well.

The Denon DHT-S517, launched in 2025, takes a more sophisticated approach. It's a 3.1.2-channel system, which means it adds a dedicated center channel for dialogue (the ".1" after the 3) plus two upward-firing speakers for height effects (the ".2"). This configuration supports Dolby Atmos – a technology that creates three-dimensional sound by bouncing audio off your ceiling to simulate overhead effects like helicopters or rain.

Audio Quality: Where the Real Differences Emerge

Immersion and Soundstage

The most significant difference between these soundbars lies in their approach to creating an immersive audio experience. The LG S40T delivers what I'd call "enhanced stereo" – it takes your TV's flat, lifeless audio and gives it depth, width, and most importantly, bass. The 200W wireless subwoofer provides substantial low-frequency output that you'll feel in action movies and music. When watching something like "Top Gun: Maverick," the jet engines have real presence and weight.

However, the LG is still fundamentally a stereo system. Sound comes from left, right, and below (the subwoofer), but there's no real sense of height or surround effects. It's like upgrading from tinny laptop speakers to a good set of computer speakers – a massive improvement, but still operating in two dimensions.

The Denon DHT-S517 operates in a different league entirely. Its Dolby Atmos capability means it can place sounds in three-dimensional space around you. Those upward-firing speakers bounce audio off your ceiling to create height effects. In practice, this means rain actually sounds like it's falling from above, and aircraft fly overhead rather than just moving from left to right. The dedicated center channel, powered by a specialized full-range driver, makes dialogue significantly clearer and more natural.

I've found that Atmos makes the biggest difference with well-mixed content. Netflix originals, 4K Blu-rays, and streaming services increasingly offer Atmos tracks that the Denon can fully utilize. The LG, while perfectly capable with standard stereo content, simply can't access this additional spatial information.

Power and Dynamic Range

Here's where things get interesting, and perhaps counterintuitive. The LG S40T has significantly more total power at 300W compared to the Denon's 40W. In raw volume terms, the LG can get much louder and has more headroom for dynamic peaks – those moments when whisper-quiet dialogue suddenly gives way to explosive action.

But power isn't everything. The Denon's lower wattage is distributed across a more sophisticated driver array. It uses seven individual drivers: two tweeters for highs, two midrange drivers, one dedicated center channel, and two upward-firing speakers for Atmos effects. This means each driver can focus on what it does best, rather than trying to cover the entire frequency range.

In smaller to medium-sized rooms, the Denon's approach works beautifully. The sound is more precise and controlled, with better separation between different elements in the mix. However, if you have a larger living room or like to really crank the volume for movie nights, the LG's extra power becomes more valuable.

Music Performance: A Clear Winner

While both soundbars are designed primarily for TV and movie content, their music performance reveals another key difference. The LG S40T handles music adequately – it's certainly better than your TV speakers – but the bass can sometimes overpower more delicate musical arrangements. The 200W subwoofer is tuned for movie impact rather than musical accuracy.

The Denon DHT-S517 includes a "Pure Mode" that bypasses all the surround sound processing and EQ adjustments. This mode essentially turns the soundbar into a high-quality stereo system, reproducing music as the artist intended. The difference is immediately noticeable – instruments have better separation, vocals are more natural, and the overall presentation is more balanced.

If you regularly stream music through your TV setup, the Denon justifies its higher price through this versatility alone. The LG is perfectly fine for background music or the occasional song, but it's not designed with serious music listening in mind.

Connectivity and Smart Features: Modern Conveniences

Both soundbars include the connectivity options you'd expect in 2024-2025, but with some important differences. The LG S40T offers HDMI ARC (Audio Return Channel), optical input, USB port, and Bluetooth 5.3. The newer Bluetooth 5.3 standard provides more stable connections and better range compared to older versions – I've noticed fewer dropouts when streaming from my phone across the room.

The standout feature for LG TV owners is the WOW Interface, which displays soundbar controls directly on your TV screen. It's a small touch, but it makes adjusting settings much more intuitive than fumbling with a separate remote. The Sound Sync technology also helps LG TVs and soundbars work together more seamlessly.

The Denon steps up with HDMI eARC (enhanced Audio Return Channel), which supports higher-quality audio formats and greater bandwidth. While regular ARC handles most content fine, eARC ensures you're getting the full quality from high-end sources like 4K Blu-ray players. The Denon also includes an analog 3.5mm input, which might seem old-fashioned but proves useful for connecting devices that don't have digital outputs.

The Home Theater Experience: Where Priorities Matter

For dedicated home theater use, the choice between these soundbars depends heavily on your priorities and room setup. The Denon DHT-S517 creates a more authentic cinema-like experience through its Dolby Atmos processing. When watching "Dune" or any modern blockbuster with an Atmos soundtrack, you'll hear details and spatial effects that simply aren't accessible to the LG.

The Denon's Night Mode compresses the dynamic range, making late-night viewing more neighbor-friendly without losing dialogue clarity. This feature has become essential in apartment living – you can still enjoy action movies without worrying about complaints from next door.

However, the LG S40T shouldn't be dismissed for home theater use. Its higher power output means it can better fill larger rooms with sound, and that 200W subwoofer delivers visceral bass that you'll feel in your chest during action sequences. For many viewers, this physical impact is more important than surround sound accuracy.

The LG's AI Sound Pro feature attempts to automatically optimize audio based on content type, though it's not as sophisticated as the Denon's manual sound modes. Still, it's helpful for viewers who don't want to constantly adjust settings.

Technical Innovations and Recent Improvements

Since their respective releases, both manufacturers have refined their approaches based on user feedback and advancing technology. The LG S40T benefits from improvements to LG's AI Sound processing, which better recognizes different content types – news, sports, movies, music – and adjusts the sound profile accordingly.

The Denon represents a newer generation of soundbar design that prioritizes driver specialization over raw power. This trend reflects the industry's growing understanding that well-implemented lower-power systems can outperform higher-wattage alternatives through better engineering and smarter processing.

Both soundbars include wireless subwoofers, eliminating the cable runs that plagued earlier systems. The pairing process has become more reliable over the past few years, though I still recommend placing the subwoofer relatively close to the main bar during initial setup to ensure a strong connection.

Value Proposition: Understanding What You're Paying For

At $156, the LG S40T offers exceptional value for anyone primarily focused on improving TV audio. You're getting substantial bass response, clear dialogue enhancement, and enough power to fill most living spaces. The wireless subwoofer alone would cost nearly as much if purchased separately.

The nearly 100% price premium for the Denon DHT-S517 at $302 is justified by its additional capabilities: true 3D audio processing, superior music reproduction, more sophisticated connectivity, and future-proofing through eARC and Atmos support. You're not just paying for better sound – you're investing in technologies that will remain relevant as content creators increasingly adopt immersive audio formats.

Making the Right Choice for Your Situation

The decision between these soundbars ultimately comes down to your priorities, room size, and how you consume content. Choose the LG S40T if you have a budget under $200, primarily watch traditional TV content, need to fill a larger room with sound, or want the simplest possible setup. It's particularly compelling for LG TV owners who can take advantage of the integrated features.

The Denon DHT-S517 makes sense if you can stretch your budget to around $300, watch content with Dolby Atmos soundtracks, listen to music regularly through your TV setup, or want the most immersive possible experience in a smaller to medium-sized room. It's also the better choice if you're planning to keep your soundbar for many years and want to ensure compatibility with future audio formats.

Both soundbars will dramatically improve your audio experience compared to TV speakers. The LG delivers excellent bang for your buck with straightforward, powerful performance. The Denon provides a more sophisticated, immersive experience that justifies its higher price through superior technology and versatility. Your choice depends on whether you prioritize value and power or advanced features and future-proofing.

LG S40T 2.1 Channel Soundbar Deals and Prices

Denon DHT-S517 Soundbar with Wireless Subwoofer Deals and Prices