The RCA connector is one of the oldest ways that we still use to connect video (and audio) to a Television set. Virtually every person who uses a TV has become very familiar with the yellow, red and white cables that magically transform a black TV screen into a quality image and booming sound (ideally). This method of connecting a system to a TV is still alive and very active, although its usage is declining because of the new types of connections are gaining prominence. RCA connectors have some distinct disadvantages when compared to newer types of cables, but they are still a viable way of attaching different kinds of video and audio signals.
Today, RCA connectors are usually configured to transmit video and audio signals. However, in RCA connectors, every signal must be transmitted through its own single cord. This is why the video and audio cables are separate, and the left/mono (white) and right (red) cables are also separate. Because of the separate cables, RCA connectors can be a mess, especially with complex signals, which can require seven or more cables to set up the correct visual/audio settings. For some people, this can be a significant disadvantage, especially compared to the newer HDMI cables, which can transmit high definition visual and surround sound audio signals all in one cable.
The most popular usage of RCA connectors is in the red, white and yellow cables mentioned earlier, where the red and white cables transmit the right and left audio signals, respectively. The yellow cable is called a composite video cable. On its own, it only transmits the video signals, and can’t carry any audio signal. Because of this, it is sometimes seen by itself, without any RCA connectors for audio. Composite video had become the standard way to connect a TV with a video output until the rise of High-definition television, and the increased amount of information the signal needed to contain.
In order to effectively render HD signals through an RCA connector, different parts of the signal needed to be split across different RCA cables. This is called component video – and the composite video (yellow) cable is replaced by red, green and blue cables that combine to transmit an HD visual signal. The audio cables remain the same; although either the red audio or visual cable will be marked differently to hep avoid confusion. Each of the three component video cables transmits a very different visual signal, so connecting only one or two of them would dramatically distort the picture, especially in its coloring.
Many people believe that the quality a digital signal like what is carried in an HDMI connection is inherently superior to that of the analog signal an RCA connector provides. However, this is mostly a myth; there are some advantages to a digital signal, and also to an HDMI connection, but there is no universal quality difference between the two. As a matter of fact, any separation between the quality of picture between digital and component video is usually a matter of what device is being used. In some cases, RCA connectors will display a better picture than a digital connection, and vice versa.
However, the difference in quality between component and composite video is clear and easily noticeable. A standard composite video cable simply can’t carry enough information to transmit an HD signal. This is mirrored in the price difference between the two – a component video cable will usually cost about $10 more than a composite video cable. RCA connectors are generally at least a foot long, and the more expensive cables can stretch to about 20-30 feet before losing signal quality.