An Overview of Consumer Electronics Connectivity
Brought to you by Impact Acoustics
“ For a list of all the ways technology has failed to improve the quality of life, please press three.” - Alice Kahn
This quote is certainly applicable to consumer electronics. From the very first commercially produced radios to the latest in high-definitiontelevision technology, the manner in which the components used to deliver our news, music, movies and entertainment are interconnected seems to have escaped logic. For both the newcomer and the old hand alike, connecting equipment in the most efficient and effective manner can be a painful chore. It is hoped this article will improve your background knowledge concerning potential A/V systemconnection schemes and where each is most appropriate. The next time you find yourself in a “connectivity quandary” perhaps the ideas shared here will help you to quickly solve the riddle of which wire goes where and why!
HDMI (High Definition Multimedia Interface) is a trademark of HDMI Licensing LLC. Developed by Sony, Hitachi , Thomson (RCA), Philips, Matsushita (Panasonic), Toshiba and SiliconImage, HDMI was created as a digital interface standard for the consumer electronics market.
The HDMI protocol combines high-definition video, multi-channel audio, and inter-component control in a single digital interface. This lone interconnect has the ability to transmit uncompressed digital video and up to eight channels of audio from source to display. Even more, the HDMI connection enablesaudio/video components to share data and commands, thus unifying an oft-disjointed collection of “boxes” into a real, working system. Based on Silicon Image's TMDS ® technology, HDMI is also fully compatible with PCs and display devices incorporating the Digital Visual Interface (DVI) standard.
For all of its amazing ability, the HDMI connector is surprisingly compact and robust. Based oncopper cables (as opposed to optical fibers), HDMI makes few demands as to cable length and bend radius. Runs to 50 feet or more are easily accommodated. HDMI may well be the perfect way to transmit high definition images to a ceiling mounted projector or from multiple source components to a single control processor. HDMI is rapidly finding its way into many upscale home cinema products.
DVI(Digital Video Interface) is a trademark of the Digital Display Working Group, an amalgam of corporations headed by Intel and including such powerhouses as Compaq, Fujitsu, Hewlett Packard, IBM, NEC and Silicon Image. The DVI connection was designed as a replacement for the P&D (Plug and Display) standard, itself an upgrade from the digital-only DFP format. Designed primarily to connect a computerto an LCD flat panel monitor, DVI has found applications in advanced consumer electronics image devices where it is used to deliver digital video from a source to a display. One drawback for DVI, that is not a major concern with HDMI, is the length of the connection. DVI is limited to about 20 feet. Beyond this length signal degradation quickly becomes evident.
There are three types of DVIconnections: DVI-A, DVI-D, and DVI-I. Let’s look at each in turn.
The “A” in DVI-A stands for analog. DVI-A carries a DVI signal to an analog display such as a traditional computer CRT. DVI-A is seldom, if ever, encountered in the home theater realm. In the words of the immortal Forest Gump, “one less thing…”
Digital video at last! DVI-D transfers uncompressed digital video in itsnative format between source and display or between components. DVD-D precludes the typical digital-to-analog/analog-to-digital conversions between a computer’s video card and monitor and provides a higher quality and faster (wider bandwidth) interface. DVI-D is the interface used on the equipment of interest to the majority of readers of this site. Fortunately, DVI-D and the next iteration have...