HDMI stands for High Definition Multimedia Interface. An HDMI cable is digital interface connector that transmits both video and audio signals. A single HDMI cable can be used to replace all of the cable connections between a high definition television and other high definition devices, such as a Blu-ray player.
Other methods can be used to connect home theater video components, such as component video, S-video and DVI (digital visual interface). These are legacy type connections that may not have the ability to work properly with some of the latest high definition technologies, such as 1080p resolution and Deep Color. Most HDTVs require the use of an HDMI cable to achieve 1080p resolution from Blu-ray or HD DVD players or cable boxes. It is therefore safe to assume that you should use a quality HDMI cable, at least when matching 1080p video components to any 1080p HDTV.
Are all the cables the same?
No. According to the official HDMI site, there are two types of cables. Older standard Speed cables, also called Category 1, support 720p and 1080i resolutions. Standard Speed cables are not rated for 1080p. High Speed cables, also called Category 2, are rated for all HDTV resolutions, including 1080p. A Category 1 cable has been tested for speeds up to 75 MHz, while a Category 2 cable is approved for up to 340 MHz. All version 1.3 cables are Category 2 cables.
Do I need to purchase expensive cables?
No, but you should purchase cables from a quality manufacturer. The price on many Monster cables exceeds $100 per cable, but good quality cables can be found for as little as $20. If you have a 720p or 1080i system with a short cable run, almost any cable should work. If you are working with 1080p HDTV equipment, you might want to invest more than $5 for HDMI cables. I’m using a Philips 6 foot High Speed HDMI Cable that I found at Wal-Mart for $35. The cable is certified for 1.3a and works great.
Whether you are using a $120 Monster cable or a $10 El-Cheapo cable, it is important to keep all audio and video cables away from power cords and cables. AC current can create problems with hum on audio cables and can distort video signals. A good rule of thumb is to always keep audio and video cables and speaker wires at least six inches away from power cords whenever possible–and never bundle audio or video cables together with power cords.
What are all the different versions, such as 1.0, 1.1, 1.2 and 1.3?
The HDMI standard has evolved since it was introduced in 2003. Each new version adds new capabilities. The current standard is 1.3b. The versions are more related to the capabilities that may or may not be required by your home theater components as well as the ability of the cable to deliver those features without loss of quality. All of the versions support 1080p when the cables are certified. The important part to remember is that the HDMI standards refer to the components in a home theater system and not the HDMI cables. The certification on the cable just means that the cable meets the requirements for the standard, but more important is the fact that all HDMI cables that are certified for at least the minimum 1.3 standard will work with 1.3a 1.3b components. In other words, an HDMI 1.3 cable is the same as a 1.3a or 1.3b cable. Nothing has changed with the newer cables, therefore, there is no reason to upgrade to newer cables unless an older 1.3 cable is defective. If you have an older 1.0, 1.1 or 1.2 cable, you will want to upgrade it to a newer 1.3 cable in order to achieve a 108p resolution and assure compatibility with newer audio and video components.
What is the maximum length for an HDMI cable?
The HDMI specifications do not limit cable length, but it is intuitive that long cable runs will lose signal strength. The longer the cable length, the higher the quality requirement become in order to prevent signal degradation or loss. Devices such as HDMI repeaters are available that amplify a signal when very long cable runs are required. There are also special cables with built-in signal amplifiers called active, boosted, amplified or equalized cables that are powered by the HDMI wiring and therefore do not need an external power supply.
Although I have not tried it, from what I have read it is safe to use cables without amplification for runs of up to 10 meters (32.8 feet). It is interesting to note that an AV amplifier with HDMI connectors is considered to be a repeater.