Four questions, about a minute. Pick an answer for each and the card at the bottom tells you what kind of soundbar to look for.
Answer all four questions to see your result.
A TV's built-in speakers are thin and point down or backwards, which is why dialogue turns to mush and explosions have no weight. Any soundbar fixes part of that by being wider, louder and aimed at you. How much more it fixes depends on three things: whether it has a dedicated centre channel for voices, whether it has real low-frequency hardware, and whether it tries to place sound above or beside you.
That last point is where marketing runs ahead of physics. A single bar in front of the sofa can widen the picture and, with clever processing, suggest height. It cannot put a helicopter behind your head. If sound from behind matters to you, the honest answer is separate rear speakers, and that is what the top tier of the picker will tell you.
Tier 1, a simple 2.1 bar. Two channels plus a subwoofer. It will lift dialogue and add some bass for a modest sum. It is the right answer for a small room or a bedroom TV. The pick in this tier is the LG S40T: a 2.1-channel, 300 W bar with Dolby Digital and DTS decoding, Bluetooth and an ARC HDMI output.
Tier 2, a bar with a centre channel and a sub. A 3.1 layout gives voices their own speaker, which is the single most useful upgrade for people who say they cannot follow the dialogue. If you mostly watch speech-led drama, this is where the money is best spent.
Tier 3, a single Dolby Atmos bar. Atmos adds height information to the soundtrack, and a bar that is built for it will do its best to project that from the front. The Sonos Beam Gen 2 does it with processing from forward-facing drivers, five amplifiers and an HDMI eARC socket, and does without HDMI passthrough and DTS:X support. For a medium room and a mixed diet of films, it is a sensible centre of gravity.
Tier 4, a flagship bar, ideally with rears. The Sonos Arc Ultra is built around Atmos, with 14 drivers and Sonos's Sound Motion woofer. It has a single HDMI eARC port and no DTS:X. For a large room, the real jump comes from adding wireless rear speakers and a subwoofer to a bar like this, not from the bar alone.
Look at the back of your TV for an HDMI socket labelled ARC or eARC. Plain ARC carries compressed surround such as Dolby Digital, which is what most 2.1 bars want. eARC has the bandwidth for the lossless and Atmos soundtracks that Tier 3 and Tier 4 bars are built to use. If your TV only has an optical output, you will get ordinary surround and no Atmos, whatever the box says.
One more check costs nothing: in the TV's sound menu, set the output to the external speaker or HDMI ARC, and switch off the TV's own sound effects so the audio is not processed twice.
Many people living in flats should be wary of a big subwoofer. Low frequencies travel through floors and walls much better than voices do. If you answered that bass is a problem, favour a bar with a night mode or a dialogue boost, keep the subwoofer level low, and think about a setup that puts the voice channel first. You will lose some thump, not much clarity.
The three picks below match the tiers: a bargain 2.1 bar, a mid-priced Atmos bar and a flagship. They are chosen to suit the film-watching in this piece, not because anyone paid to be listed. Links are affiliate links; prices change, so the picks show what is current. Specs are the makers' own, and we have not listened to any of them.