Connections

New sets have several different types of inputs that can handle varying levels of quality. That's because manufacturers have added new connections as higher-quality signals have become available. They've left the other inputs in place to work with older equipment. Using the appropriate input can improve the picture quality. Most new sets have HDMI as well as component-video, S-video, composite-video, and RF.

HDMI inputs provide a digital connection to devices such as standard DVD players, Blu-ray high-def disc players, digital-cable boxes, satellite receivers, audio/video receivers, and some computers. HDMI carries audio and video on one cable, simplifying hookup compared to using a three-jack component video input and separate two-jack audio cables. A digital-to-digital connection has the potential to transmit pristine picture quality, though our tests so far haven't shown that picture quality via HDMI is always significantly better than via a component-video input.

Component-video inputs use green, blue and red RCA connectors, and are typically labeled YPbPr. They receive video as three separate signals: two for color, one for luminance. In our tests, component-video inputs have typically yielded video quality close to that of HDMI. Component-video inputs, which can accept high-definition signals (something S-video cannot), are often used with Blu-ray and DVD players, satellite receivers, cable boxes, and video games. They don't carry audio signals, so separate audio cables are required.

S-video inputs, which are small round jacks with four tiny holes, split the video signal into two parts, color and luminance, so picture quality is usually slightly lower than with component-video, most notably in color fidelity. S-video connections are most often used with standard-def components such as standard DVD players and some cable or satellite boxes. They don't carry audio signals, so separate audio cables are required.

Composite-video inputs combine all the parts of the video signal into a single stream, so quality is a step below S-video. Composite-video connections are often used to connect a VCR, cable box, camcorder, or game console. A composite-video cable is a single cable with a yellow RCA jack; like other inputs, it's paired with red and white audio jacks.

Antenna/cable, or radio frequency (RF), inputs (sometimes called F-type or 75-ohm coaxial inputs) are the most basic connections. When carrying standard-definition analog signals, they typically provide the lowest detail of all video inputs and are most susceptible to noise and interference. But with digital signals, including high-def, they can provide top picture quality. They're sometimes labeled as UHF/VHF inputs on a TV. An RF input might be the only way to connect an antenna and some older cable boxes and VCRs. It's the only analog input that carries both picture and sound on a single cable. The others all require separate audio connections (red and white RCA jacks) for stereo sound.

TVs now typically include several other types of inputs. For example, many come with a memory-card slot or USB port. That enables you to view digital photos or videos stored on a USB flash card. A growing number have an Ethernet jack for connecting the TV to a home network or the Internet. You can connect a digital camera or camcorder directly to the TV if it has a USB, or IEEE 1394/Firewire input. A VGA input lets a TV accept signals from virtually any computer; DVI inputs are compatible mostly with newer midrange computers.