Finding the Perfect Dolby Atmos Soundbar: Denon DHT-S517 vs Polk Audio Signa S4

When your TV's built-in speakers just aren't cutting it anymore, upgrading to a Dolby Atmos soundbar can transform your living room into a mini movie theater. I've spent considerable time testing both the Denon DHT-S517 and Polk Audio Signa S4, two popular soundbars that promise immersive three-dimensional audio without the complexity of a full surround sound system.

Both soundbars were released in 2022, entering a crowded market where manufacturers were racing to bring Dolby Atmos technology to more affordable price points. Since their launch, we've seen software updates improve their performance, and the competitive landscape has pushed both companies to refine their approaches to spatial audio.

Understanding Dolby Atmos Soundbars

Before diving into the comparison, let's clarify what makes these soundbars special. Dolby Atmos is a surround sound technology that adds a "height" dimension to audio by bouncing sound off your ceiling. Traditional surround sound moves audio left, right, front, and back. Atmos adds "up" and "down" to create a three-dimensional bubble of sound around you.

Both the Denon DHT-S517 at $302 and Polk Signa S4 at $299 use a 3.1.2 channel configuration. This means three main channels (left, center, right), one subwoofer channel (the ".1"), and two height channels (the ".2") that fire sound upward to reflect off your ceiling. It's like having invisible speakers floating above your head.

The key considerations when choosing between these soundbars include how well they handle dialogue (crucial for movies and TV), how convincingly they create that overhead Atmos effect, how they perform in different room sizes, and whether their connectivity options match your setup needs.

Audio Performance: Two Different Philosophies

Sound Quality and Tuning Approaches

Testing these soundbars side by side reveals fundamentally different audio philosophies. The Denon takes what I'd call a "precision-first" approach, emphasizing clarity and accuracy over raw impact. When watching dialogue-heavy scenes in movies like "The West Wing" or "Mad Men," the Denon's seven-driver array—including two 4.7" x 1.6" racetrack-shaped midrange drivers and dedicated 1" tweeters—delivers remarkably clear vocal reproduction.

The Polk, by contrast, prioritizes immersion and spatial impact. Its seven-driver configuration uses SDA (Stereo Dimensional Array) technology, which artificially widens the soundstage to make audio seem like it's coming from beyond the physical boundaries of the soundbar. When testing with action sequences from "Top Gun: Maverick," the Polk created a noticeably wider sound field that made jet engines seem to roar from the far corners of my living room.

This difference becomes particularly evident in bass handling. The Denon's wireless subwoofer uses a 5.25" front-firing driver in a more compact enclosure, delivering what I found to be tighter, more controlled low-end response. Bass lines in music maintained their definition, and movie explosions had punch without overwhelming the midrange frequencies where dialogue lives.

The Polk's subwoofer takes a different approach with its larger 5.9375" downward-firing driver. This design choice creates more room-filling bass that you feel as much as hear. During action scenes, the Polk's subwoofer adds more visceral impact, though sometimes at the expense of precision. The downward-firing design also means bass response varies more with subwoofer placement—putting it on carpet versus hard flooring noticeably changes the character.

Dolby Atmos Implementation: Height Effects That Matter

The real test of any Atmos soundbar is how convincingly it creates overhead effects. Both soundbars use upward-firing drivers—the Denon employs two 2.5" full-range drivers while the Polk uses 2.625" height drivers—but their tuning creates distinctly different experiences.

In my testing room with 9-foot ceilings, the Polk consistently produced more noticeable overhead effects. During the opening scene of "Blade Runner 2049," where rain falls throughout the frame, the Polk made individual droplets seem to materialize above and around my listening position. The Denon produced the same effect, but more subtly—you had to listen for it rather than being immediately impressed by it.

This difference reflects their design priorities. The Polk's more aggressive upward projection works well in medium to large rooms where you have adequate ceiling height and distance for sound reflections to develop properly. The Denon's more conservative approach works better in smaller spaces where aggressive height effects might become distracting or poorly defined.

Consumer Reports noted that while both soundbars reasonably reproduce the height dimension, the Polk's approach creates a more dramatic "wow factor" that many users prefer, even if it's sometimes less accurate to the original mix intention.

Dialogue Clarity: Where Denon Shines

One area where the Denon DHT-S517 clearly outperforms its competitor is dialogue handling. The dedicated Dialogue Enhancer feature offers three adjustable levels (Low, Medium, High) that specifically boost vocal frequencies without affecting background music or sound effects. This isn't just a simple EQ adjustment—it's sophisticated processing that identifies and enhances speech patterns.

During testing with complex action sequences like the battle scenes in "Avengers: Endgame," I could follow every line of dialogue even when explosions and music competed for attention. The Dialogue Enhancer's High setting proved particularly useful when watching late at night with reduced volume levels.

The Polk's VoiceAdjust technology achieves similar results but with less precision. It raises vocal volume across the board rather than targeting specific speech frequencies. While effective, it sometimes made dialogue sound slightly artificial, particularly with certain actors' voices that fell outside its optimization range.

For households where multiple family members have different hearing sensitivities, or for anyone who frequently watches content with heavy accents or challenging dialogue, the Denon's superior dialogue processing justifies its slightly higher price.

Connectivity and Modern Features

HDMI and Input Flexibility

The Denon DHT-S517 offers superior physical connectivity with two HDMI inputs—one for eARC (enhanced Audio Return Channel) connection to your TV, plus an additional HDMI input for connecting sources directly to the soundbar. This extra input proves valuable if your TV has limited HDMI ports or if you want to connect a gaming console directly to take advantage of the soundbar's audio processing.

Both soundbars support HDMI eARC, which allows your TV remote to control soundbar volume and enables the highest-quality audio formats to pass through from streaming apps. However, the Polk's single HDMI input means you'll rely more heavily on your TV's built-in smart platform or need additional HDMI switching.

The Denon also includes a USB-A input for direct playback from flash drives—a feature that seems old-fashioned but proves surprisingly useful for playing high-quality music files or when troubleshooting audio issues.

Streaming Capabilities: Polk's Major Advantage

Where the Polk Audio Signa S4 dramatically outperforms the Denon is in streaming flexibility. The Polk includes built-in Wi-Fi connectivity, allowing direct access to streaming services like Spotify, Apple Music, and Amazon Music without requiring a phone, tablet, or streaming device.

This Wi-Fi capability transforms daily usage patterns. Instead of grabbing your phone to stream music through Bluetooth, you can use voice commands or the soundbar's app to access your playlists directly. The convenience factor becomes particularly apparent during parties or background music scenarios where you don't want to tie up your personal device.

The Denon limits you to Bluetooth 5.0 connectivity for wireless streaming. While Bluetooth quality has improved significantly—and the Denon's implementation sounds quite good—it still requires an active connection to a source device and doesn't support the highest streaming quality tiers that some services offer through Wi-Fi connections.

For households that prioritize streaming music and podcasts, the Polk's Wi-Fi connectivity provides significantly more flexibility and better integration with modern smart home ecosystems.

Room Size and Placement Considerations

Small to Medium Rooms: Denon's Sweet Spot

In smaller listening environments—think apartments, bedrooms, or cozy family rooms under 250 square feet—the Denon DHT-S517 consistently performed better in my testing. Its more controlled acoustic approach prevents the sound from becoming overwhelming in tight spaces, and the front-firing subwoofer design offers more flexible placement options.

The Denon's precision tuning becomes an advantage when you're sitting relatively close to the soundbar. Dialogue remains clear and natural, and the Atmos effects don't become exaggerated or distracting. The subwoofer's front-firing design also means it works well tucked into entertainment centers or placed against walls—common requirements in smaller spaces.

Large Rooms: Polk's Spatial Advantage

For larger living rooms or open-concept spaces exceeding 250 square feet, the Polk Signa S4 demonstrates clear advantages. Its SDA technology creates a wider apparent soundstage that helps fill expansive spaces more effectively. The more aggressive Atmos processing also works better when you have adequate room for ceiling reflections to develop properly.

The Polk's downward-firing subwoofer design provides more omnidirectional bass distribution, which helps maintain consistent low-frequency response across a wider listening area. This becomes important when you have multiple seating positions or when people move around during casual listening.

During testing in a 350-square-foot great room, the Polk maintained engaging audio from various positions around the space, while the Denon's more focused approach worked best from the primary seating area.

Technical Evolution Since Launch

Since their 2022 release, both soundbars have received firmware updates that improved their performance. The Denon's updates focused primarily on HDMI compatibility and Bluetooth stability, addressing early user reports of connection drops with certain TV models.

The Polk's Wi-Fi connectivity has enabled more substantial improvements through over-the-air updates. New streaming service integrations, improved voice assistant compatibility, and enhanced room correction algorithms have expanded its capabilities significantly since launch.

These updates highlight an important consideration: Wi-Fi-connected devices like the Polk can continue evolving their feature sets, while Bluetooth-only devices like the Denon remain more static after purchase.

Music Performance: Different Strengths

Critical Listening and Audiophile Preferences

For serious music listening, the Denon DHT-S517 offers a "Pure Mode" that bypasses all surround sound processing and EQ adjustments, delivering uncolored stereo playback. This feature appeals to audiophiles who want their soundbar to disappear acoustically, presenting music as the artist intended.

Testing with high-quality recordings revealed the Denon's more neutral tonal balance. Jazz recordings maintained their spatial information and instrumental separation, while classical music preserved the natural dynamics that cheaper soundbars often compress.

Casual Music and Party Scenarios

The Polk's approach favors casual listening and social scenarios. Its wider soundstage creates more engaging background music, and the stronger bass response adds excitement to pop, rock, and electronic genres. The Wi-Fi streaming capability also makes it more practical for party playlists and spontaneous music sessions.

The Polk's multiple EQ presets (Movie, Music, Night modes) provide more customization options for different musical genres, though purists might prefer the Denon's more accurate default tuning.

Value Analysis and Long-Term Considerations

Price-to-Performance Ratio

At nearly identical pricing, these soundbars offer different value propositions. The Denon DHT-S517 at $302 provides superior build quality, more robust amplification (150W total system power), and additional connectivity options. Its higher per-feature cost reflects better component quality and more conservative engineering.

The Polk Signa S4 at $299 delivers more features per dollar, particularly when you factor in the Wi-Fi streaming capabilities that would require additional hardware with the Denon. For mainstream users who prioritize convenience and modern connectivity, the Polk offers better bang for the buck.

Future-Proofing Considerations

The Denon's extra HDMI input provides valuable future-proofing for evolving entertainment setups. As 4K gaming and high-refresh-rate content become more common, having direct HDMI connectivity to the soundbar helps maintain audio quality that might be compromised through TV passthrough.

The Polk's Wi-Fi connectivity offers different future-proofing advantages through continued software updates and emerging streaming service integrations. As smart home ecosystems evolve, Wi-Fi-connected devices typically maintain better compatibility with new platforms and features.

Making Your Decision

After extensive testing with both soundbars, I'd recommend the Denon DHT-S517 for users who prioritize dialogue clarity, have smaller listening spaces, need multiple HDMI inputs, or prefer more accurate audio reproduction. Its precision-focused approach and superior dialogue processing make it particularly well-suited for serious movie watching and critical music listening.

Choose the Polk Signa S4 if you want maximum immersion from Dolby Atmos effects, have a larger room to fill, prioritize streaming convenience, or prefer more dramatic bass response. Its wider soundstage and built-in Wi-Fi make it better suited for family entertainment and casual listening scenarios.

Both soundbars deliver significant improvements over TV speakers and represent excellent values in the competitive Dolby Atmos category. Your choice should ultimately depend on your room size, listening priorities, and how you consume audio content. Neither will disappoint, but understanding their different strengths ensures you'll choose the one that best matches your specific needs and preferences.

The good news is that at these price points, both the Denon DHT-S517 and Polk Signa S4 deliver performance that would have cost significantly more just a few years ago. Whichever you choose, you'll enjoy a substantial upgrade to your home entertainment experience.

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