Why can coaxial cable cords carry HDTV but audio video cables cannot?

Answer 1

HDTV needs a very high data flow to support the fine detail of the images. The standard method for carrying video signals for decades has been with co-ax cables designed to carry video. The cables are designed to have certain characteristics and are tuned to work with both the video source and the receiver.

Standard definition video is a far lower data rate. Although small diameter cables are not co-ax, over a short distance, the errors caused by them are insignificant. HD signals cannot tolerate the same level of error because of the much higher data rate.

Additionally, most HDTV sources such as cable and satellite receivers and Bluray players are designed to output HD signals only on an HDMI connector. Although other connections are possible, HDMI has been promoted by the industry in an attempt to reduce piracy. It is possible to encrypt signals on and HDMI link using a copy protection system. It makes it much harder to extract the signal and make copies of HD content. Although many devices have analog video and audio connections on RCA (phono) connectors, they are deliberately restricted to standard definition to limit the quality of copies that may be made using the analog output.

HDMI is not actually a co-ax connector. It uses several twisted pairs in a similar way to computer network connectors. Like the co-ax cables, the cables are tuned to suit the source and receiver circuitry to reduce errors in data transmission.