Connections

HDMI

Digital-to-digital connections could show improved picture quality compared to analog connections, though that hasn't always been the case in our tests so far. But an HDMI connection is often required to receive "upconverted" (quasi-HD) signals from a standard-def upconverting DVD player. Digital connections are copy-protected (using a technology called HDCP), so they may allow content providers, such as Hollywood studios, to control your ability to record certain programming.

There are several versions of HDMI. The newest, the 1.4 specification, offers much different capabilities than earlier versions. Perhaps the most game-changing feature is the addition of an Ethernet channel, which allows a single HDMI cable to carry Internet data (up to 100 megabits per second) along with digital audio and video. That means the rising number of TVs and Blu-ray players that connect to the Internet won't require a separate Ethernet jack.

HDMI 1.4 also supports 3D (which needs two separate 1080p video streams), and video resolutions four times greater than the best resolution offered today, 1080p. One day, home displays will be able to support the "4K (4096x2164/24Hz and 3840x2160/30Hz) resolutions" now found in many digital movie theaters.

The downside to a new HDMI spec, of course, is more confusion for consumers, as there will now be four different "versions" of HDMI 1.4 cables: standard and high speeds, both with and without the Ethernet channel. That means you'll have to read the labels carefully in order to get the cable you need and avoid paying more for one you don't.

HDMI 1.3, has twice the bandwidth of its predecessors, enabling some additional features not included in earlier iterations. A new HDMI-based feature, called HDMI-CEC (consumer electronics control), is designed to allow multiple components, including those from different brands, to be controlled via a single remote control, often with the press of a single button. (We haven't confirmed yet that this feature works between brands as intended.) CEC is an optional feature for HDMI 1.3, so you need to check a product’s feature list to see if it supports CEC. But some manufacturers have given this feature a proprietary name—Panasonic, for example, calls it EZ-Sync, while Sony's is Bravia Theatre Sync.

With its greater bandwidth—almost twice that of earlier versions—HDMI 1.3 enables a significant number of possible picture and sound improvements that weren't available with earlier HDMI iterations (HDMI 1.0, 1.1 or 1.2). For example, a feature called Deep Color increases the maximum number of colors, from millions to billions, that can be displayed. That can help eliminate "banding" (the visible lines that can result in transitions from one color to another) and improve contrast. HDMI 1.3 also supports a new, wider color gamut, called xvYCC, which has about twice as many colors as current HDTV signals. Other HDMI 1.3 features include Lip Sync, which automatically compensates for the lag between audio and on-screen action (which often looks like bad dubbing), and support for Dolby TrueHD and DTS-HD Master Audio, new high-quality "lossless" compressed digital audio formats.

While all these enhancements sound exciting, the reality is that there is still relatively little content that can take advantage of these new features, particularly on the video side. But be aware that in order to fully enjoy the improvements, every single device in the signal chain—program material, source components, a receiver, and the TV—has to support the same version of HDMI and implement each of the specific features. Right now, these features are all optional, so manufacturers can pick and choose which to implement.