Digital Trends

We are just starting to see new high-end HDTV's, DVD players, and audio products including HDMI (High Definition Multimedia Interface) connectivity.  HDMI, which was conceived as the successor to DVI, for the passage of digital video signals also has the capability to carry uncompressed digital audio and video signals together through the use of one cable and connector.   This means that it has the potential to bypass all other digital audio connectors including coax and optical (TosLink) and 1394.  Wow!  The implications are staggering.  With 5.1 HDMI included in A/V Receivers, DVD players/recorders (including future Blu-ray and HD DVD players), Satellite Receivers and Cable HD Receivers, it eliminates the need for digital audio — coax and optical — and 1394 entirely to carry digital audio signals.  It also makes it easy for the consumer to attach one cable instead of several from their Satellite/Cable HD Receiver, and DVD player to A/V Receiver to TV.

However, I was very troubled at the recent C.E.D.I.A. Expo to find out that one has to be careful about HDMI these days.  Why do I say this?  Both Audio and Video products currently on the market that utilize HDMI only passes 2.0 digital audio, and not full-blown 5.1 surround sound audio.  These products include A/V Receivers, DVD players/recorders, and HDTV's.    Of course, to be fair, Silicon Image — the creator of HDMI -- claims that it can do 5.1 audio easily.  However, the hard fact is that none of the connections currently on the market today are passing 5.1 audio!  In an ideal world, HDMI has the capability to carry all HD video and digital audio signals including Dolby Digital, DTS, DVD-Audio and SACD via one connector plus full-blown HDTV and HD-DVD signals as well.  This is a terrific scenario as is anything that will cut down on cabling clutter is a great thing.  The back of my home theater looks like hundreds of strands of spaghetti wires.

I'm just warning caution right now, and making you aware of the limitation of current products in the marketplace.  We haven't eliminated everything just yet, and you should be aware of it.  Clearly, it will take time for the audio companies to include full-blown HDMI switching capability as it took several years for component video switching to become commonplace.  Today, several manufacturers now include component video switching with up conversion (from composite and S-Video) on numerous models, which is pretty neat.    

Several upscale HDTV's now include HDMI input(s), and a handful of DVD players include HDMI output.  Sending both digital audio and video signals directly to the TV via HDMI does simplify matters up converting those already pristine DVD images to near HD quality.  Audio, on the other hand, from that DVD player will only be sent at Dolby Digital 2.0 quality to be handled by the TV's internal audio system.  And, if you're using the TV's speakers and Dolby Digital processing, you won't know the difference.