The short answer
The same television can look and sound noticeably different depending on how it is connected — and the difference costs nothing to fix. Three mistakes account for most of it: the wrong grade of HDMI cable, a console plugged into a port that does not carry high frame rates, and a soundbar not running over eARC, so Dolby Atmos never arrives. This guide covers each, including the Hong Kong-specific question of receiving broadcast TV.
Step one: work out what each HDMI port actually does
Most people assume four HDMI ports are identical. They are not — a television typically has at least two special ones:
| Device | Which port |
|---|---|
| Soundbar / AV amplifier | The port labelled eARC (or ARC) — usually only one per set |
| PS5 / PS5 Pro / Xbox Series X | A port that carries high frame rates (4K120). Some sets support it on all four ports, some on only one, and some cap the whole set at 4K60 |
| Set-top box, streaming stick, Blu-ray player | Any remaining port is fine |
| Computer | Use a high-bandwidth port and switch the input to PC mode — chroma handling differs |
How do you tell which port qualifies? Do not trust the words "HDMI 2.1" on the box — that is an interface version, not a bandwidth guarantee. Read the "HDMI (High Frame Rate)" row on the official specification sheet: it should state 4K 120 or 4K 144. Samsung's own support documentation gives an example where a Neo QLED paired with an Xbox Series X must use HDMI 4, "the only port that supports 120hz" on that set. Sizes within one series can differ, so check model by model. For why frame rate matters at all, see our refresh rate article.
Choosing an HDMI cable: there are four official grades, the rest is marketing
Plenty of cables are sold as "HDMI 2.1 cables". No such certification exists. These are the official certified grades:
| Official cable grade | Bandwidth | What it carries |
|---|---|---|
| High Speed | 10.2Gbps | 1080p and 4K@30 — not worth buying for a new set |
| Premium High Speed | 18Gbps | 4K60 with HDR — plenty for films, streaming and set-top boxes |
| Ultra High Speed | 48Gbps | 4K120 and 8K60 — essential for gaming |
| Ultra96 | 96Gbps | 8K@60 and 4K@240 at 4:4:4 — for the newest interface generation, not yet needed in a typical 2026 home |
In practice: Premium High Speed is enough for films and set-top boxes; go straight to Ultra High Speed the moment a console is involved — the price difference is small and not worth economising on. Longer runs are more failure-prone, so beyond about 5 metres choose a cable carrying the official certification label (the box has a QR code you can verify).
Soundbars: eARC versus ARC versus optical
All three produce sound. What differs is the format that survives the trip:
- eARC — HDMI officially states support for up to 192kHz, 24-bit, uncompressed 5.1 and 7.1, 32-channel uncompressed audio, plus DTS-HD Master Audio, DTS:X, Dolby TrueHD and Dolby Atmos. In short: lossless Atmos needs eARC.
- ARC — the older channel, compressed formats only. Streaming's compressed Atmos usually gets through; a Blu-ray's lossless track does not.
- Optical — the oldest route, typically compressed 5.1 with no Atmos. Its advantage is that it sidesteps HDMI handshake problems entirely.
How to wire it: one HDMI cable from the soundbar into the television's eARC port, with everything else plugged into the television. It is the simplest layout and the soundbar follows automatically when you change input. If your soundbar has its own HDMI inputs you can instead route the console through the soundbar — but only if that soundbar passes 4K120 through, otherwise it becomes the bottleneck.
Five checks when Atmos will not appear: (1) is eARC switched on in the television's settings; (2) is the cable genuinely in the eARC port; (3) is the cable at least Premium grade; (4) is the audio output set to passthrough / original format rather than PCM (PCM guarantees no Atmos); (5) does the app or disc actually carry an Atmos track.
Note that our soundbar warranty runs for one month — different from the three years on televisions, so factor that in before ordering. Browse models in the soundbar collection.
Consoles: what the makers actually say
PS5 and PS5 Pro — PlayStation officially requires "an Ultra-High-Speed HDMI Cable that supports HDMI 2.1" into "an HDMI port that supports HDMI 2.1". If the setup is wrong, PlayStation names the symptoms: the signal drops to 1080p 120Hz, or nothing appears at all. Seeing either does not mean the set is broken — it means the connection is wrong.
Samsung owners, one extra step — full bandwidth is not enabled out of the box. Go to Settings → Connection (or General) → External Device Manager → Input Signal Plus (older firmware calls it HDMI UHD Color) and enable it for each HDMI port individually. Without it, the right port and the right cable still will not give you 4K120.
Nintendo Switch 2 — Nintendo's official specification gives a maximum of 3840×2160 at 60fps on a television, with 120fps available when 1920×1080 or 2560×1440 is selected, and HDR10 support. So a Switch 2 alone is no reason to upgrade your cable for 4K120.
Also switch on Game Mode (or automatic low latency, ALLM). It is the single biggest reduction in input lag available to you — a bigger difference than any picture setting. For game-focused sets, see the gaming TV collection.
Hong Kong broadcast TV: set-top box or streaming?
Two facts to separate first:
- Hong Kong digital terrestrial television uses the DTMB standard (GB 20600-2006), in force since 1 August 2007 — different from the DVB-T2 common in Europe and Southeast Asia.
- A television's built-in tuner follows its market version, and versions do not all carry the same tuner. So "will this set pick up free-to-air channels from an aerial" is a question to answer from that model's official specification sheet, not with a blanket rule. Ask before you order.
If the set cannot, or you simply do not use an aerial, Hong Kong offers three routes: a set-top box (myTV SUPER, Now TV and similar — these plug into HDMI and have nothing to do with the set's tuner), streaming apps installed on the television itself, or a pay-TV operator's box. Streaming apps do carry system requirements — myTV SUPER, for instance, lists Samsung Tizen 5.0 or above, LG webOS 4.0 or above, and Android 9.0 or above. Our TV operating system article compares what each platform can install.
One remote for everything: HDMI-CEC
Samsung calls it Anynet+, LG calls it SIMPLINK, everyone else calls it HDMI-CEC — the same feature. With it on, switching on a console wakes the television and jumps to the right input, and the television remote controls soundbar volume. If you find the set-top box switching itself on annoying, this is where to turn it off.
Five symptoms and their usual cause
| Symptom | Most likely cause |
|---|---|
| Gaming caps at 1080p 120Hz, or a black screen | Input Signal Plus not enabled, or the cable is not Ultra High Speed |
| Soundbar plays but never shows Atmos | Audio output set to PCM, or not running through the eARC port |
| Picture blanks for a second and returns | Cable too long or under-specified — try a certified one |
| Green or purple tint, or sparkling noise | Colour depth exceeding available bandwidth — enable Input Signal Plus or change cable |
| Gaming feels half a beat behind | Game Mode is off |
If a picture problem persists after the connections are right, what is covered and how on-site visits work is set out in the international-version warranty policy. To start from choosing a set, see the smart TV collection.
Frequently asked questions
Do I need a new HDMI cable for gaming?
It depends on the console. For 4K120 on a PS5, PS5 Pro or Xbox Series X, PlayStation officially requires an Ultra High Speed HDMI cable supporting HDMI 2.1, into a port that supports HDMI 2.1. A Switch 2 tops out at 4K60 on a television, reaching 120fps only at 1080p or 1440p, so it alone is no reason to upgrade. For films and set-top boxes, Premium High Speed is enough.
Why is my soundbar not producing Dolby Atmos?
Work through five checks: is eARC enabled in the television's settings; is the cable in the eARC port; is the cable at least Premium grade; is audio output set to PCM (which guarantees no Atmos — choose passthrough or original format); and does the app or disc carry an Atmos track at all. HDMI states that formats such as Dolby TrueHD, Dolby Atmos and DTS:X require eARC.
Are all four HDMI ports on a TV the same?
No. Usually only one supports eARC for a soundbar, and high-frame-rate capability varies model by model — some sets support 4K120 on all four ports, some on only one, and some cap the entire set at 4K60. Do not rely on "HDMI 2.1" printed on the box; read the "HDMI (High Frame Rate)" row of the official specification sheet.
How do I receive Hong Kong free-to-air channels?
Hong Kong digital terrestrial television uses the DTMB standard (GB 20600-2006, in force since 1 August 2007). A set's built-in tuner follows its market version and versions differ, so check that model's official specification sheet and ask before ordering. If you are not using an aerial, a set-top box, streaming apps or a pay-TV operator's box all work — none of them depends on the set's tuner.
My PS5 shows a black screen — is the TV faulty?
Usually not. PlayStation states that an incorrect 4K120 setup shows exactly this: a drop to 1080p 120Hz, or no picture. On a Samsung, go to Settings → Connection (or General) → External Device Manager → Input Signal Plus and enable it for that HDMI port, then confirm the cable is Ultra High Speed. Those two steps resolve most cases.
About this article
Cable grades and eARC format support come from HDMI Licensing Administrator official material; console requirements from PlayStation and Nintendo official specifications; menu paths from Samsung official support documentation; the Hong Kong terrestrial standard from the Communications Authority. Port capability for any individual model follows that model's official specification sheet.
