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So you want to buy a brand new HDTV, A/V Receiver, Blu Ray player and some of you have an old VCR that you want to incorporate into your home theater experience. There is something that you probably didn't even think about, much less budget for, and that's how you are going to tie it all together. This is the job of the cable. There are many kinds of cables out there all with different uses. Today's column will discuss the various kinds of AV cables on the market and what they are used for.

Before we get started, we want to talk a bit about cost. Cables are the new cash cow of the big box retailers. Many retailers make more profit selling a premium priced HDMI cable than they do selling a budget LCD TV. They tell you that you need the cable to get the best picture possible. Please don't be fooled by this ploy. There have been studies that show a $12 HDMI cable performs every bit as well as the $200 premium priced cable. (Cheap vs. Expensive cable comparison done by "Marketplace" on CBC Print Article or Video).

Our recommendation has always been to buy high quality cables but don't over-spend. You can buy a fully certified two-meter HDMI 1.3a cable for less than $15. In our experience, it will work every bit as good as the $200 premium priced cable! With that said, there still may be times in which you would want a higher quality, more expensive cable. For instance, if you need longer cable lengths, or if your cable will be installed in-wall, it would be better to invest a bit more in quality cable.

Without further ado, here's what you need to know about cables:

Video Cables

  • Composite Video - This is the single, "yellow" RCA plug video cable. It transmits analog video and is typically used by VCRs and older (or very cheap) DVD players.  Composite Video cables do not support HDTV. Odds are you have a ton of these around the house, since just about every video product on the market supports it, and will typically include one of these cables in the box.
  • S-Video - A single video cable with a strange connector that looks a little like the old PS2 mouse and keyboard connectors. It has a metal ring with 4 metal pins inside.  It transmits analog video that is slightly better than Composite video, but it is still not compatible with HDTV.  This cable was used on higher end VCRs and DVD players back in the day. A one meter S-Video cable goes for about $13 at the big box retailer and about $2 online.
  • Component Video - This is the "three video cables hooked together" system.  The individual cables in the set are usually color coded Red, Green and Blue, or labeled Y, Pb, Pr. It transmits analog video vastly superior to Composite and S-Video and is HDTV capable.  When we first got into HD, manufacturers were not including these cables in the box but today they are. High quality component cables go for about $16 online.
  • VGA - This cable is typically used to connect a computer to a monitor, and is rarely used for Home Theater applications.  It is analog and very similar in quality to Component Video cables.  Many HDTVs support it, and it does support High Definition.
  • DVI - The name stands for Digital Visual Interface and it's a single video cable that transmits, as the name implies, digital video.  It transmits excellent quality video identical to early versions of HDMI and is becoming more and more popular as a replacement to VGA in the PC industry.  One unique aspect of the cable is that it can transmit either Analog HDTV (which is VGA compatible) or Digital HDTV (early HDMI compatible) over the same interface.  Although it doesn't support the most recent advances in HDMI specification, it is HDTV capable.
  • HDMI - High Definition Multimedia Interface.  Another single digital video cable, but it should really be in a category of its own, because it is the only video cable that can also transmit audio.  It is the easiest and most convenient way to wire for HDTV because the one connection gets you the best quality digital video and digital surround sound of any connection type. The recently released HDMI 1.3 specification expands the capability to support an even higher quality than typical HDTV and is ideal for use with the next generation High Definition video discs like HD DVD and Blu-ray.  Needless to say, you can use this cable to watch High Definition.

Audio Cables

  • Stereo Audio - These are the two, "red and white combined" RCA plug audio cables.  They typically complement a Composite video installation and are intended to be used to transmit analog, stereo audio. Although they can support matrix surround sound, like Dolby ProLogic, they do not support the discrete 5.1 surround (Dolby Digital) used in most HD content. These connectors are not recommended for connecting High Definition Televisions.
  • Digital RCA or Digital Coax - This is a single RCA cable used to transmit digital audio.  It does support surround sound or multi channel audio and can be used for HDTV.
  • Optical (Toslink) - This is a single cable with a funny connector also used to transmit digital audio via light pulses.  It has very similar capabilities to the Digital RCA cable and also supports surround sound, multi channel audio.
  • HDMI - The most capable audio connector for HDTVs.  With HDMI 1.3, it now has the capability to support the lossless, perfect quality audio formats used on HD DVD and Blu-ray discs.  It is the recommended cable for connection of HDTVs, both audio and video.

Other Connections

Although these go a bit beyond “Newbie” knowledge, we thought you might want to know about some other connector types you may have seen, as well as some things coming down the road.

  • Firewire or IEEE 1394 - Firewire is used in video for many PC and CE devices, but hasn't really penetrated the Home Theater market. It has been used by some devices for transfer of compressed HDTV content for backup and archive purposes. Its time may have come and gone in that space.
  • DisplayPort - DisplayPort is the main competitor to HDMI.  It is a single cable that supports both digital audio and digital video and has its own copy protection scheme similar to HDCP called DisplayPort Content Protection (DPCP).
  • Video over USB - Some companies are investigating using a standard USB cable to transmit Digital Video.  It would support multiple displays by daisy chaining them together.  This sounds like neat functionality, but is still in the experimental phase.
  • Wireless HDMI - Many companies, such as Tzero, are actively working on a Wireless implementation of the HDMI spec, and some products are starting to hit the market. Once this functionality is native to the devices you buy, you'll no longer need to connect anything with a cable.  Just plug them into the wall and you're ready to go. Keep in mind that these current wireless transmission methods convert and compress the HDMI signal and will result in a degradation of signal. And although they are HDMI-compliant, there aren’t yet any wireless HDMI transmission schemes approved by Simplay Labs, which certified HDMI connectors.

Posted by The HT Guys, March 18, 2008 9:58 AM

About The HT Guys

The HT Guys, Ara Derderian and Braden Russell, are Engineers who formerly worked for the Advanced Digital Systems Group (ADSG) of Sony Pictures Entertainment. ADSG was the R&D unit of the sound department producing products for movie theaters and movie studios.

Two of the products they worked on include the DCP-1000 and DADR-5000. The DCP is a digital cinema processor used in movie theaters around the world. The DADR-5000 is a disk-based audio dubber used on Hollywood sound stages.

ADSG was awarded a Technical Academy Award by the Academy of Motion Picture Arts and Sciences in 2000 for the development of the DADR-5000. Ara holds three patents for his development work in Digital Cinema and Digital Audio Recording.

Every week they put together a podcast about High Definition TV and Home Theater. Each episode brings news from the A/V world, helpful product reviews and insights and help in demystifying and simplifying HDTV and home theater.