TV Sound Explained: Dolby Atmos, eARC and Do You Need a Soundbar?
If you care about how your TV sounds, the short answer is yes: a soundbar is worth it, and even a modest one is a big step up from built-in speakers. The upgrade you notice first is clearer dialogue and some actual bass, which is exactly what most people are missing. The rest of this guide explains why the speakers inside your TV struggle, what Dolby Atmos and eARC really mean once you strip the marketing off them, and how to pick a soundbar without overspending.
Why built-in TV speakers are usually weak
Modern TVs are built to be thin. That is great for how they look on a wall and terrible for sound, because good audio needs two things a slim panel cannot easily give it: physical speaker size and an enclosed volume of air for bass. There is barely any depth behind the screen to fit a decent driver, let alone a cabinet, so the speakers end up small and shallow.
Where they point makes it worse. To keep the front of the TV all screen, most sets fire their speakers downward into the stand or backward into the wall, so the sound reaches you as a reflection rather than straight on. That is a big reason dialogue can come across muddy or distant, and why you find yourself reaching for the volume during quiet talky scenes and then diving for it again when the music swells.
None of this means TV audio is broken. For casual viewing, background telly, the news, or a small bedroom set, built-in speakers are perfectly fine. The gap only really bothers you when you sit down to watch something properly.
Dolby Atmos and DTS, without the marketing
Older surround sound worked in fixed channels: front left, front right, centre, a couple of rears. Each speaker got its own dedicated feed. Dolby Atmos changes the approach by treating sounds as objects placed in a three-dimensional space, including a height dimension above you, and letting your gear work out how to reproduce that with the speakers it has. A helicopter can move over your head rather than just from one side to the other. DTS:X is the rival format that does much the same thing.
Here is the catch worth knowing. A TV can advertise that it "supports Dolby Atmos," and that is technically true, but the built-in speakers almost never do it justice. Height and surround effects need speakers that can throw sound upward and around a room, which a flat panel simply does not have. Atmos support on the TV mostly matters as a signal that the set can pass that soundtrack through to something that can actually play it, like a soundbar or an AV receiver.
eARC vs ARC: the connection that carries good sound
To get the best audio from your TV to a soundbar, you want them talking over the right HDMI socket. This is where ARC and eARC come in.
ARC (Audio Return Channel) lets a single HDMI cable send sound back from the TV to a soundbar, so you do not need a separate audio lead. It works, but its bandwidth is limited, so it can only carry compressed audio formats.
eARC (Enhanced Audio Return Channel) is the newer version, and the extra bandwidth is the whole point. It can pass high-bitrate, lossless soundtracks, which is what full-fat Dolby Atmos (delivered via Dolby TrueHD on a 4K Blu-ray) and DTS:X actually need. Worth knowing: the Atmos you get from a streaming app like Netflix or Disney+ is usually the compressed version (Dolby Digital Plus), and only disc-based Atmos via Dolby TrueHD is truly lossless. Either way, eARC is the connection with the bandwidth to carry that high-bitrate soundtrack to your soundbar intact, where ARC would fall short.
| ARC | eARC | |
|---|---|---|
| Cable | One HDMI | One HDMI |
| Bandwidth | Lower | Much higher |
| Audio it carries | Compressed formats only | High-bitrate lossless, including Atmos via Dolby TrueHD and DTS:X |
| Best for | Getting basic TV sound to a soundbar | Passing full-quality Atmos and DTS:X |
Two practical notes. Both the TV and the soundbar need to support eARC for it to work, and it is worth using a good-quality High Speed HDMI cable. If your gear is older, the fallback is an optical cable, which is reliable for stereo and basic surround but cannot carry lossless Atmos. If you are working out which HDMI ports do what on a new set, our guide to HDMI 2.0 vs 2.1 covers the sockets and what eARC needs.
Do you actually need a soundbar?
For most people who care about sound, yes. The jump from built-in speakers to even a basic soundbar is large, and the two things you notice immediately are dialogue clarity and bass. You stop riding the volume control, and action scenes get some weight behind them. A soundbar is the single cheapest upgrade that meaningfully changes how your TV sounds.
When built-in speakers are genuinely fine: casual or background viewing, small rooms where you sit close to the set, and secondary TVs you do not watch films on. If the sound already suits how you use that television, do not spend the money.
The simplest test is your own reaction. If you regularly find dialogue weak or muddy, or you are turning subtitles on just to follow what people are saying, that is the sign a soundbar will fix the thing that annoys you.
Soundbar tiers: how much to spend
Soundbars split roughly into two useful groups.
- Basic 2.0 or 2.1 bars. A 2.0 bar has left and right channels; a 2.1 adds a subwoofer for bass. This tier delivers the big upgrade most people are after: clearer dialogue and proper low end. If your main complaint is "I can't hear what they're saying," this is all you need, and you do not have to spend a lot.
- Dolby Atmos soundbars. These add up-firing speakers that bounce sound off your ceiling to create a sense of height, plus more channels for surround. They are the ones that make use of an Atmos soundtrack passed over eARC. Worth it if you want a more immersive, cinema-like effect and you have a reasonably normal ceiling for the up-firing trick to work against.
Whichever tier you choose, connect it to the TV via eARC over HDMI where both devices support it, since that is what carries the best audio. Use optical as the fallback if they do not.
The bottom line
If sound matters to you, a soundbar is the upgrade to make, and a modest 2.1 bar handles the dialogue-and-bass problem that bothers most people. Step up to an Atmos bar with eARC only if you want genuine height and surround and have a soundtrack worth feeding it. Match the connection to the gear: eARC for lossless Atmos and DTS:X, optical if that is not an option.
Picking the TV itself is the other half of the job. If you are shopping for a new set, our rundown of the best gaming TVs and our explainer on what OLED is and whether it is worth it cover the panel and feature choices that go alongside sound.