You can connect nearby devices with a short HDM cable. But, how do you solve it when you have to bridge longer distances with HDMI?
Today, almost all of us use HDMI to connect our AV systems. A cable between the Blu-ray player and the TV, one between the decoder and the TV or all devices connected to the receiver or home cinema set via HDMI. These devices are often close to each other and can therefore easily be connected with a cable of 1, 2 or 3 meters. But, how do you solve it when you have to bridge longer distances with HDMI?
Long distance HDMI
Suppose you have a beamer in the back of the room and your sources such as the Blu-ray player and the TV decoder are in the front of the room. Then you quickly need an HDMI cable of 10 meters or more. The HDMI specifications do not specify a maximum length, but the rule of thumb is that 10 meters is about the maximum that you can reliably bridge. Then you should also use well-shielded and high-quality cable. Especially when you need a lot of bandwidth (for example because you want 4K @ 60fps or even 120 fps in perfect quality), the need for a good cable is becoming increasingly important. Due to the enormous amount of data, and the higher chance of loss with a long cable, the chance of ‘sparkles’ (randomly flashing pixels) is much greater. Fortunately, other solutions exist.
Optical HDMI cables
Where a classic HDMI cable sends an electrical signal via copper wire, optical HDMI cables use fiber optic to transmit a light signal. The conversion takes place, thanks to miniaturization, in the connector itself. As a result, in some cases you hardly see any difference with a regular cable. With these cables you can quickly bridge 100 m.
HDMI over Ethernet
If you want to send HDMI signals over great distances, and maybe even send HDMI signals throughout your house, a network with CAT cables (the well-known Ethernet cables) is interesting. The CAT5 to CAT7 cables are already widely used to distribute the internet connection indoors, but you can also use these cables to distribute your audio and video signal.
All you need is an HDMI over Ethernet extender. There are various extenders (sometimes also called extenders or converters) for sale, and depending on the quality and the distance that can be bridged, you pay a few tens to a few hundred euros for this. At the transmitter an HDMI cable goes in and an ethernet cable (UTP cable) comes out, at the receiver an ethernet cable goes in and an HDMI cable comes out.
Send audio and video signals wirelessly
If it can be wired, we usually choose wired. This is to ensure that the quality is maintained and to minimize the chance of interference. But, if you really want wireless, there are also options. There are various accessories for sale that can transmit the audio and video signal wirelessly over a long distance.
The products that can send an HDMI signal wirelessly from the source to the receiver are often a lot more expensive than the other solutions, and the range is also lower because it is wireless. For example, Marmitek has a wireless solution that costs you almost 300 euros and provides a maximum range of 10 meters (in the field of view). The operation is quite simple; you connect the source, for example a Blu-ray player, with the transmitter using a short cable. This sends the signal wirelessly to the receiver, which is connected to the display directly or by means of a short cable.
In addition, a number of standards for the wireless transmission of image and sound have been worked on for years. Two of the better known standards are WHDI and Wireless HD (WiHD) . Although progress is being made in terms of laptops and computers, we hardly see these standards in the AV world. We are still waiting for widely accepted and implemented standards to transmit audio and images in high quality and over great distances.
Differences from the classic HDMI cable
All these solutions differ in a number of areas from the classic HDMI cable. You have to be aware of that, so we list them here.
- You have to connect these solutions in a certain direction. A regular HDMI cable has no direction, but an optical cable does. Even if it looks hardly any different from a regular cable. So check carefully which side of the cable you connect where.
- Some of these solutions also require a power supply, especially for wireless solutions and HDMI over Ethernet.
- Check carefully whether the chosen solution also supports all the HDMI features you require. We are thinking of ARC and CEC for example. Unlike ordinary cables, this is not always the case.