The HDMI interface allows the transition of digital audio and video over a single cable and according to many, the HDMI cables should be your first choice if you are setting up a home theater system. Since all of the latest displays and video and audio sources are HDMI-ready, connecting them with a single HDMI cable easy and far less messy. When it comes to the quality of the picture and sound, the HDMI cables do not necessarily outperform other cables, they just make your setup neater.
The main difference between the HDMI and Component Video lies in the ways they deliver the signal – HDMI is digital and Component Video is an analog format. This difference is often cited by writers, who claim that digital is always better since the analog signal is subject to degradation, but the truth is that the analog signal is rarely depreciated over short and even longer distance and most home users will obtain perfect picture even when using Component Video cables for their home theatres. While there is some truth to the assumption that using HDMI or DVI cable to link source that uses digital recording to a digital display is likely to ensure greater quality since there is no conversion, quite often the digital signals are encoded differently and scaling and processing does occur. On the other hand, using a Component Video in a setup, where a native digital display is used, the signal needs to be converted from digital to analog and this means that its quality might be altered.
One of the main disadvantages of the HDMI cables is that they cannot be run over very long distances. While the exact maximum length of the HDMI cables is not specified, most writers agree that cables, longer than 10 meters could be problematic. This depends on many different factors and for some equipment and setups, running a 15-meter HDMI cable might not be a problem at all, while in other cases, even a 6-meter cable might not work. In comparison, the analog signal can be carried over 50 to 90 meters over cables without the use of boosters. For both HDMI and Component Video cables, the quality of the cable and especially its impedance will determine if they can be used for longer distances. Most users need only short HDMI cables for their setups, but if you find yourself trying to connect source and display, which are more than 20 meters apart and want to use an HDMI cable, then you will have to buy an extender and use two or more separate cables.