Audio visual are known as RCA signal was the standard and came with most audio and visual devices including video players, camcorders, projectors, gaming consoles. The signal used to transmit the sound and video was analog and was good enough at the time. However, as technology improved and newer innovations took over, HDMI soon became the standard and started out replacing the RCA signal. HDMI produces clearer and even more reliable signal that causes crystal clear images and crisp audio. It is found in most modern entertainment accessories and works in digital form.Visit here here http://5productreviews.com/8-best-rca-hdmi/