Audio Visual Cables Explained

Modern TV and AV devices can use a large variety of different connection types, particularly if you’re using some older equipment along with new stuff. In this article I’ll try to explain what HDMI, Component, Composite and other cable types are.


HDMI is currently the gold standard of cable for connecting audio visual devices. If you can connect something via HDMI it would be the best. Often though in practice not all the devices you want to use with your TV have HDMI connections, or there simply aren’t enough in the back of the TV.

HDMI supports a variety of High Definition and Standard Definition video formats and will provide the best picture quality available. Use it for Blu-ray players, Personal/Digital Video Recorders and other High Def Media devices first. Some DVD players and Standard Definition media devices also support HDMI but only use HDMI for these if you have spare sockets on your TV.

HDMI is the simplest connection to install. Just one cable will carry video and audio. It’s hard to get lost finding where they go too! Be careful when inserting the plugs into the slots though. HDMI plugs and sockets can be damaged by rough insertion and this will evidence itself most at higher resolutions and frame rates, such as when used for 3D Blu-ray. Another thing that many people are unaware of is that HDMI sockets and plugs are rated for only a limited number of lifetime insertion cycles. So you don’t want to be plugging and unplugging them all the time, as this will eventually cause the failure of the cable or socket.


Component video is the next best method of connecting a device after HDMI. Component video is carried by a 3 RCA cable with red, green and blue connectors. These don’t correspond with the colours red, green and blue in the picture, but rather one core carries the brightness of the image, and the other two carry components of the colour spectrum which are then reconstructed into a colour image. Component video is an analogue connection, but is capable of carrying a range of formats including SD and HD formats.

Component video cables only carry video, so a separate 2 RCA cable to carry audio is also required. These typically have connectors coloured white and red. This makes for a total of 5 connectors per device connected.

I would recommend using Component for a device like a Blu-ray player, DVD player or other media device in cases where you can’t use HDMI.

Composite Video

3 RCA Composite Video and Audio cable
3 RCA Composite Video and Audio cable

Composite video has been one of the most common audio-visual connection types. Composite uses a 1 RCA cable with a yellow plug for video. Most composite cables also include a 2 RCA audio connection with white and yellow plugs, although they can be separate. Composite cables are only capable of carrying Standard Definition video and are the lowest quality of cable connection. Like component cables, composite cables also carry an analogue signal. Despite this they will still provide a decent picture from a DVD player.

As composite video provides the lowest quality of picture I would recommend only using it where there are no other options. Typically this will be for connecting older DVD players to older TVs. VCRs should also use composite. Some game consoles also still use it.

TV Pass Thru

Where you have multiple devices that need to use the TV signal, TV flyleaves are used to connect the devices. Typical devices with pass thru are Personal Video Recorders, DVD Recorders, VCRs and Set Top Boxes. Input TV signal sockets are almost always PAL BL Female, so these accept a PAL BL Male plug. Output TV sockets are usually PAL BL Male sockets, so to connect the signal from the other device to the TV you’ll need a PAL BL Female to Male cable.