Tech Terms Demystified: HDMI Switching and HDMI Repeating

By

Ralph Graves

Ralph Graves is one of Crutchfield's blog editors, and part of the company's social media team. He writes about home audio/video gear, specializing in Apple-related and wireless technologies. Ralph holds a master's degree in music composition, and his works have been released on various labels. He's served as product manager for an independent classical and world music label, produced several recordings, and worked extensively in public broadcasting. Since 1984 he's hosted a weekly classical music program on WTJU, and is also active as a blogger and podcaster.

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HDMI Switching
"HDMI Switching" is one of those terms that sounds terribly complicated and technical, but turn out to be relatively simple and straight forward. In a nutshell, a receiver with HDMI switching can select a single signal from any of the HDMI inputs going into it to send through its HDMI output.

Need a little more detail? Here goes:

HDMI (High Definition Multimedia Interface) connections are designed to handle a lot of digital data. It can carry the highest resolution video image currently available, and up to eight discrete full-range audio channels. That's why it's become the connection of choice for many high-definition TVs. That, and the fact that it lets you run a single cable to your TV for both video and audio.

A number of HD video sources, like Blu-ray DiscT players, and high-def cable and satellite boxes - even some upconverting DVD players- also send video and audio through a single HDMI cable. Without HDMI switching, you would have to plug each one of those sources directly into your TV. On a TV with only one HDMI input, if you wanted to watch a DVD, you'd plug the player's HDMI cable into your TV. And then if you wanted to check out some satellite TV, you'd have to unplug the DVD's cable and plug in your satellite box's HDMI cable.

HDMI switching lets you plug all those devices into your compatible receiver, and the receiver's built-in HDMI switcher changes the connection internally. You simply select the appropriate source.

HDMI Repeater
Now remember, with HDMI switching, it's as if you're running a cable directly from your source to your TV. A receiver with just an HDMI switcher never processes the HDMI audio - it just passes it through.

If you want multichannel sound to play through your home theater system, you'll want a receiver with an HDMI repeater. Rather than just passing through the HDMI signal, a receiver with a repeater will process the audio portion of the signal coming in, and then send on ("repeat") the video portion to the HDMI output going to your TV.

Not every receiver that does HDMI switching has an HDMI repeater. But all of the receivers that do have an HDMI repeater also do HDMI switching.