Looking into my retro tech closet, I can see how easy life used to be – or not. Game consoles, DivX players, network receivers and so on had dozens of outputs to offer something for every situation – S-Video, Scart, RCA, Composite, optical/coaxial (SP/DIF). All you needed was an impossibly large box of cables and everything-to-everything adapters, and there was always a quirky input somewhere on the TV or receiver that used the right cable to make the right connection.
HDMI simplified everything. You now only need one cable for everything. My TV has (almost) only HDMI connections, modern consoles and 4K players like Apple TV 4K or Fire TV Stick still have a power input and an HDMI output. That’s all you need.
That’s true as long as you want to connect a device with an HDMI output to a device with an HDMI input. Console and stick to TV, done. As soon as it gets even slightly more complex, the simplicity is over.
Beamer instead of TV? No problem, also works with HDMI – but then the sound is gone. Most projectors don’t have speakers, and very few at least output the sound to connect an AV receiver. AV receivers solve many problems if they have enough HDMI inputs. And are new enough – because my AV receiver in the living room is great, but it can’t do 4K. So throwing it away is out of the question.
The console, Apple TV & Co. must therefore be connected directly to the television, which then outputs the audio signal back to the receiver. This works as long as the TV has enough HDMI inputs (mine does) and outputs the audio signal without errors (mine doesn’t). I have an unpleasant jerking sound with squeaky background noise when the 4K signal goes into the TV and the sound then flows digitally to the receiver – whether via HDMI with ARC (Audio Remote Channel) or via the optical SP/DIF output of the television. Of course, this is an isolated case, but there are many of them – and we show a possible way of dealing with them.
HDMI audio splitter / audio extractor
If you want to extract the sound from an HDMI signal, you can use a special adapter. They have an HDMI input and an HDMI output and an additional audio output, which outputs a jack socket for headphones, cinch sockets for an analogue stereo signal or SP/DIF for a digital 5.1 signal, depending on what is required.
What exactly you need depends on the cable situation on site and the required HDMI standards. Such an audio extractor costs 15 to 20 euros in the cheapest case. The devices support the HDMI 1.4 standard and output audio both digitally and analogously; the limitation lies in the resolution: full HD is not a problem, 4K is only possible with a reduced refresh rate (30 Hz).
If you want to transmit a 4K image to a TV or projector, you should pay attention to HDMI 2.0 when buying an HDMI audio extractor. You have to pay at least 25 euros for such an adapter. As with the 1.4 model, there are HDMI inputs and outputs, as well as an analogue and a digital audio output.
No matter what the resolution, audio extractors need power. In the best cases, you can get it via a USB cable. Power adapters are usually not included, but you don’t need them either: almost every television and AV receiver has at least one USB port free, to which you can connect a stick for firmware updates, for example – the splitter then also gets its own from it Energy.
HDMI switcher
If you have more HDMI players than suitable inputs, an AV receiver often takes over the job of the switch. However, the devices are large and comparatively expensive – and if you already have a good-sounding hi-fi system, buying a new one doesn’t necessarily make sense when a simple HDMI switch is actually enough.
Corresponding devices are available from around 10 euros. You have one HDMI output and two, three, four, six or even more inputs. Depending on the model, switching is done with a mechanical switch, with pushbuttons, remote control, automatic or a combination of these things. Again, it is important to pay attention to the HDMI standard. Cheap models manage Full HD and 4K with restrictions, for a small surcharge there are switches that can also handle 4K resolution at 60 Hz.
Since the automatic switching often doesn’t work as well as you would expect – for example, when a Fire TV stick or an Xbox turns on briefly because of a firmware update, although you’re watching a film on Blu-ray – and the If the way to the switch is not up-to-date, we would recommend a device with a remote control. If you like, you can use smart infrared transmitters such as the Broadlink RM Mini 3 with Alexa connection to activate the switching routines via smart home app or voice command.
By the way, better equipped HDMI switchers bring the function of the audio splitter with them: This 65-euro model from Amazon , for example, is a four-way switcher and audio extractor in one.
HDMI splitter
If you want to fire several outputs from one input, for example monitors in several rooms at the same time or projector and television at the same time, you need an HDMI splitter (also called 1-in-2-out adapter). The simplest adapters of this type (from about 8 euros) even work in both directions – they either make one output from two inputs or supply two outputs from one input signal.
This is easily sufficient for normal audio and video signals. However, it can become complex when HDCP copy protection is involved, for example when playing a Blu-ray or a 4K stream. HDCP is intended to ensure that the video signal between the player and the output device is encrypted throughout – if it is used, you cannot just connect several televisions or monitors.
HDMI cable
Which cable is the right one? While this used to be very simple – after all, digital transmission is digital transmission – the world of HDMI cables has become significantly more complex. And because the topic is so complex, we have dedicated a separate story to it: Which HDMI cable for 4K, HDR, 8K & Co.
Conclusion
I have an audio extractor in the living room because my receiver isn’t 4K-capable and the TV’s audio output is causing problems. In the office I have an old Full HD projector with a single HDMI input that is connected to a switcher with an audio extractor – so I can use Fire TV Stick, Xbox and Nintendo without having to switch plugs. An RM Mini 3 takes care of switching, which I can control by voice via Alexa. It’s good for comfort and the environment – it means my old hi-fi amps can still be used occasionally even though one doesn’t even have HDMI – and the other isn’t from the 4K era.
The article The best cordless projectors: Top 5 mobile projectors for on the go is exciting for film fans . We explain everything to do with the right sound in the speaker, subwoofer and AV receiver guide: You really need that for good home cinema . Also worth reading is the article Displayport instead of HDMI: (USB) cables, adapters & Co. from 4 euros.
