What You Must Know- HDMI Extension (2)

【Writer/Pre-sales Engineer】

Do you remember the technical article we shared last month? After getting the point about the situations of requiring HDMI extenders, you can select the extension mode. This time, we’re going to give you some tips about how to choose the most suitable cable for your HDMI extension.

There’re various ways for HDMI extension. Firstly, you should select compatible and easily-attained cables. The transmission technique applied with the cable would decide the transmission distance, video quality, and the transmission type of the extender. The transmission type includes IR, USB, RS232, audio, CEC, and HDCP.

Network cable

network cable applied to HDMI extension accounts for 90% in the market. TCP/IP, HDBaseT, SDVOE, and other supplier-defined transmission techniques are normally used on the cables.



HDMI Optical Fiber Extender (picture source: fuji.com.tw)

Optical cable

the extenders applying optical cable are normally used for the transmission distance over 200M. Recent years, optical technique is rapidly developed; its cable’s price is almost as the same as the network cable’s. Joint welding is also a troublesome matter. To solve the problem, you could have the welded cable custom made from the factory directly. However, we suggest you ensuring the piping space and extension distance first. Another commonly-known way is transforming the optical cable into the HDMI module. The optical length is fixed for sale. You can find 20M-500M in the market. This kind of cable is called HDMI optical cable. There’s the chip inputted to the two sides of the HDMI joint. For point-to-point transmission with long distance, this is a favorable solution.

HDMI Optical Fiber Extender (picture source: fuji.com.tw)

4K HDMI 2.0 Active Optical Cable (picture source: ATEN)

Coaxial cable

cable TV and antenna both apply coaxial cables, which can also be used for HDMI transmission. However, it’s quite difficult to be found in the present market. There are two transmission modes of the coaxial cable: SDI and DVB-T (Digital Video Broadcasting-Terrestrial). However, it’s inconvenient to apply DVB-T and it would cause compressed and delayed video. Thus, it’s rarely used in the present market.


HDMI Coaxial Extender (picture source: DIY Trade)

Wireless transmission

the wireless transmission protocol of different chip suppliers can be varied. The different transmission techniques used for different frequency bands would also affect the transmission effect. With 2.4G transmission, the signal would be easily interfered by the on-site equipment with the similar frequency band. With 5G, the transmission distance would be shorter; the signal penetration would lose more as well. The transmission effect of 60G is quite high, but it costs more. There’s also the commonly-known wireless presentation remote/box that should be used with software. You need to install the specified APP on the smartphone first. And then, this APP could encode the video and transmit to the receiving box. After that, the receiving box would decode the video and then output HDMI signal. For example, the AirPlay built in iPhone is the app for transmitting HDMI signals to Apple TV. However, this transmission mode would occupy the smartphone’s efficacy. At its heart, wireless transmission devices should be certified with NCC for sale. The transmission distance is also restricted with the same space. With a partition wall, the transmission efficacy would greatly decreased.


Wireless HDMI Extender (picture source: BicCamera.com)

HDMI repeater

this extension solution is constructed with a repeater connecting with HDMI cable at the both side. It costs much because of the inclusion of HDMI cable’s and repeater’s price. It’s better to select the HDMI cable with good quality so that the transmission distance would be longer to achieve the premium effect.


HDMI 4K*2K Repeater (picture source: Yahoo)


HDMI Repeater (picture source: Rakuten)

How to choose the chip for the extender that is most suitable with your need? Here’re some questions you could ask yourself first:

  1. How long is the extension distance?
  2. Is there any electro magnetic interference on site?
  3. Are you strict in the clarity of the video?
  4. Do you mind video delay?

Basically, more expensive chip would cause higher price of HDMI extender. If you can’t accept any video delay or you pursue the excellent video quality, we suggest you purchasing HDBaseT extender. However, the price is comparatively high and the application is not very flexible. There are many professional projectors built in HDBaseT input; you could purchase HDBaseT transmitter only so that the receiver’s cost can be saved. If you need an extender supporting longer transmission distance and better anti-interference feature, the TCP/IP type (transmitting signals via network switch) is recommended. Moreover, the chip for this type can be varied so that we strongly suggest you inquiring the supplier about the transmission rate (100Mbps or 1Gbps), L2 network switch requirement, video delay, video compression, and etc.

Here is the brief introduction. We hope it could help you. If there’s any further questions, please feel free to contact our pre-sale engineer (patrick@bxb.tw).