Cables and settings behind a television

For 4K and a soundbar, one certified High Speed HDMI lead with Ethernet is enough for most rooms; eARC only matters if the soundbar handles object-based audio, and it changes which socket on the television does the work. Cables disappear behind the furniture rather than inside the wall, and the sockets stay reachable. The order of the three decisions, lead, socket, housing, is what keeps the back of a television tidy for years.

Which HDMI cable is actually needed for 4K and a soundbar?

A single certified lead covers the ordinary case. The certification programme run by HDMI Licensing Administrator tests cables against the bandwidth they claim, and the label on the packaging is the only reliable signal: a certified Premium High Speed cable is tested for 18 Gbps, which carries 4K at 60 Hz with 4:4:4 colour, and a certified Ultra High Speed cable is tested for 48 Gbps, which carries 4K at 120 Hz and 8K at 60 Hz. Anything sold without that label is a claim, not a test.

For a television and a soundbar, the audio side rarely needs the full 48 Gbps. A soundbar receiving a compressed stream or a PCM stereo signal travels well inside 18 Gbps. The reason to buy Ultra High Speed is the screen, not the speaker: a games console or a computer at 4K 120 Hz needs the wider pipe, and the lead between console and television is the one that must be certified for it. The lead between television and soundbar can be the older certified type without loss.

Length matters more than people expect. Passive certified leads are tested up to about 3 metres for Ultra High Speed and about 5 metres for Premium High Speed. Beyond that, an active optical cable is the honest answer, and it is directional: the plug marked source goes to the console or box, the plug marked display goes to the television. Reversing it produces a black screen that looks like a fault and is not one.

The practical rule is one certified lead per device, bought at the length actually needed, with the certification label kept in the packaging until the return window closes. A drawer of untested spare leads is how a household ends up swapping cables at midnight to find the one that works. The same discipline applies on the audio side, where connecting a soundbar and a television depends on knowing which socket carries the return channel and which cable type the soundbar expects.

What does eARC change when a soundbar is added?

ARC, the Audio Return Channel, lets the television send sound back down the same HDMI cable that brings picture from a source. It carries compressed formats: Dolby Digital Plus, and in practice the streaming services that use it. eARC is the later version of that channel, with far more bandwidth, and it carries uncompressed multi-channel audio and object-based formats such as Dolby Atmos and DTS:X without compression.

The change is not automatic. Three conditions must all hold: the television must have an HDMI socket labelled eARC, the soundbar must have one too, and the cable between them must be certified for the bandwidth. A certified Premium High Speed lead usually suffices for eARC, because the return channel uses a fraction of the cable's capacity, but an old unbranded lead from a drawer is the most common cause of a soundbar that works for a week and then drops out.

Settings decide the rest. In the television menu, the audio output is set to the HDMI or eARC option rather than to the internal speakers, and the digital audio format is set to pass through rather than to PCM, otherwise the television decodes the stream and sends stereo down the cable. On the soundbar, the input is set to the HDMI socket rather than to optical, and any automatic standby is left on. Where both devices support HDMI-CEC, the soundbar wakes with the screen and the television remote controls the volume; the feature is called different names by different makers, and it is the same handshake underneath.

If the soundbar is older and has only an optical input, none of this applies. Optical carries compressed surround and stereo, not object-based audio, and it does not switch on with the screen unless the soundbar has its own signal sensing. That is a limitation of the socket, not of the settings.

How do you hide the cables without boxing in the sockets?

The sockets are the part that must stay reachable. A television is unplugged, moved, and reconnected more often than any other object in the house, and a socket sealed behind plaster or a fixed panel turns a five-minute change into a decorating job. The aim is therefore not to hide the sockets but to hide the cables while leaving the sockets accessible.

Four methods cover most rooms. A surface trunking run along the skirting, painted to match, keeps everything reachable and is the least invasive. A cable spine or a fabric sleeve gathers the leads into one line down the wall, which suits a wall-mounted screen. A floor-to-ceiling channel behind a piece of furniture hides the run without touching the wall. A brush plate, a wall plate with a slot of bristles, lets cables pass through a hole in the wall while closing the gap around them, and it can be unscrewed when the layout changes.

Chasing the wall is the option that removes the most visible cable and creates the most future work. Where it is done, the usual arrangement is a single wide conduit with a drawstring left inside, so a later cable can be pulled through without opening the plaster again. The sockets themselves sit in a recessed box behind the screen, deep enough for the plugs and the bend of the cable, and the television mount is chosen so the screen stands off the wall by the depth of that box.

Where do the boxes live?

The boxes are the streaming stick, the games console, the router, the recorder, and the power supply for each. They generate heat, they need ventilation, and they need to be reachable for a reset. A closed cabinet with no gap at the back is the usual mistake: the devices throttle, the fan noise rises, and the remote control signal fails through a solid door.

The workable arrangement is a shelf or a cabinet with an open back and at least a hand's width of clearance above each device, positioned so the infrared receiver faces the room. A small infrared repeater solves the closed-door case, with the emitter inside the cabinet and the receiver on the front edge. Power is the other constraint: a single switched extension lead with surge protection, rated for the total load, keeps the number of wall sockets down and gives one switch for the whole corner.

Labelling is what makes the arrangement maintainable. Each lead is marked at both ends with the device it serves, using a wrap of tape and a marker or a printed label. When a device is replaced, the lead is identified in seconds rather than traced by hand behind a cabinet. The same inventory habit that serves the rest of the house applies here: a short list of what is plugged into what, kept with the manuals, answers most questions without moving the furniture.

What the settings should be left at

Once the leads are in place, three settings are worth writing down. The television's audio output is set to the HDMI or eARC socket, with the digital format on pass through. The picture mode is set to the calibrated or film maker option rather than to the shop display mode, which is brighter and less accurate. The energy saving and standby behaviour is left at the default that complies with the EU standby regulation, since the automatic power-down after a period without input is what keeps the idle consumption low.

A television corner then needs no further attention until a device changes. The certified lead stays where it was bought for, the soundbar wakes with the screen, the sockets remain reachable behind the screen, and the boxes sit in moving air with their leads labelled. That is the whole arrangement, and it is the one that survives the next upgrade.

The cable names used here, Standard, High Speed and Ultra High Speed, are not shop labels. They come from the bandwidth tiers set out in the HDMI specification, which is published outside the household network and is not a partner or a sponsor of this record. The settings noted above follow the same tiers, so a cable bought for one television may not carry the same signal on another. Check the tier before buying, and write the cable type on the label at the back of the set.

The cables behind a television are rarely planned. They are added as devices arrive, and the settings follow the same pattern: a picture mode changed once, a sleep timer set, a network name typed in and forgotten. Before changing any of it, it helps to know what a house spends energy on, because a television is only one line in a larger account. A second Kept entry on this subject takes the same approach, reading the room before touching the cables.