What Is an RCA Cable?

If you've ever connected a CD player or DVD player to your TV, you likely used an RCA cable. A simple RCA cable has three color-coded plugs extending from one end that connects to three corresponding colored jacks on the back of a TV, projector, or another output device. It carries audio and video signals from the component device to the output device (i.e. a television or speakers).

The RCA cable is named for the Radio Corporation of America, which first used it in the 1940s to connect phonographs to amplifiers. It entered popular home use in the '50s and is still in use today. The two most common types are composite video and component.

Composite Video RCA Cables

The colors used in composite RCA cables are usually red and white or black for right and left audio channels and yellow for composite video. Composite video is analog, or non-digital, and carries all the video data in one signal. Because analog video is made up of three separate signals to begin with, squeezing them into one signal reduces the quality somewhat.

Composite video signals typically consist of 480i NTSC/576i PAL standard definition video signals. It's not designed to be used for high-definition analog or digital video signals.

Component Cables

Component cables are more sophisticated and are sometimes used on HD TVs. Component cables have three video lines usually colored red, green, and blue and two audio lines colored red and white or black. The two red lines usually have an additional color added to distinguish them.

Component RCA cables are capable of much higher resolutions than composite video cables: 480p, 576p, 720p, 1080p, and even higher. 

Uses for RCA Cables

Although an HDMI cable is a more modern way to connect devices, there are still plenty of opportunities to use RCA cables.

They can be used to connect a variety of audio and video devices, such as camcorders, to TVs or stereos to speakers. Most high-end camcorders have all three RCA jacks, so the signal entering or leaving the device goes through three separate channels—one video and two audio—resulting in a high-quality transfer. Lower-end camcorders usually have only one jack, called a stereo jack, which combines all three channels. This results in lower-quality transfers because the signal is compressed. In either case, RCA cables transmit analog, or non-digital, signals. Because of this, they cannot be plugged directly into a computer or other digital device. RCA cables connect amplifiers to all sorts of devices. 

Quality of RCA Cables

Several factors affect the quality, price, and performance of RCA cables:

• Materials: The connectors on RCA cables are often gold, silver, or copper. As you might expect, the gold connectors are the most expensive. They're also better than silver and copper connectors at preventing oxidation, but not as good at electrical conductivity. The silver connectors are best for electrical conductivity with the copper cables coming in a close second and the gold cables falling far behind. Other suitable materials are nickel, zinc, and tin.
• Cable Length: Cable length has a negative effect on signal quality. Buy a cable that is only as long as you need it to make the connection for the best signal quality.
• Shielding: A well-shielded cable delivers a better signal than one that lacks robust shielding.
• The other end of the cable: If possible, match the material used in the other end of the cable to the material used in the connectors. Don't match tin with gold or silver with gold. Those combinations can cause problems because of an electrolytic reaction.

Frequently Asked Questions

• How do you connect HDMI output to RCA input? You can use an HDMI to AV/RCA Converter. Connect the converter to a power source, then connect the HDMI cable, and red and white RCA cables, to the converter. Connect the converter to the TV or other device, and then connect the yellow video cable from the converter to your device.
• What is a low-level RCA output? Low-level audio output is usually four volts or lower and classified as an un-amplified signal transmitted through RCA cables. Low-level is also referred to as line-level inputs.