DVD Cables Explained
Now, with DVD on the scene in a big way there is a growing amount of confusion concerning the myriad of connectors used for DVD audio and video. This new terminology page endeavors to help explain the differences.
Because of the potentially high quality sound available with DVD attention to the audio cables is more important than ever. You must 'Choose Wisely'.
Digital Audio (the best!)
There are two kinds of connectors used to provide true six channel digital sound. The first and most common is the optical cable (Toslink). This is a thin, wire like cable that has a snap connector on each end. The jacks on the receiver or decoder and the DVD player usually have a protective cover that must be removed. If more than one optical jack is provided only uncover the one that will be in use. Keep the covers safe so you can replace it over the jack should you wish to move the unit. The lesser seen connector is the SP/DIF (IEC60958) connector. This is a coaxial or fiber optic cable that can carry the six discrete channels to a decoder or receiver. In both cases the sound is the best possible and will work for all DVD players. I have had information provided to me that there is also a RCA type connector that is compliant with IEC60958 standards. I have personally not seen this one so if anyone has any additional information on this cable format please let me know. According to the DVD audio specifications, DVD players must transmit PCM, the method used for music CDs and at least one MPEG-2 format usually Dolby Digital 5.1 (formerly called AC-3) or DTS (Digital Theater Sound). An increasing number of DVD players and decoders will handle both Dolby 5.1 and DTS. DTS discs require more bandwidth or space on the DVD and therefore often do not have the added features that have made DVDs so popular. Most people can not tell the difference between the two formats in normal home conditions.
Toslink Cable: RCA Cable: Coaxial Cable:
Component analog audio: (better response)
With some DVD players there are provisions for six channel analog output provided provided by an internal digital/analogue decoder. This method will require a receiver with six separate inputs or three sets of stereo receivers. In most cases you will not have control of the volumes for the six channels. Some set ups require a special cable with RCA connectors on one end and a DB-25 connector on the other. This may be difficult to find or replace.
Stereo/surround analog audio: (average response)
Every DVD player has two RCA outputs designed for stereo output. Since all DVDs are MPEG-2 encoded this stereo signal can be decoded and downmixed to Dolby Surround/ProLogic by a Prologic enabled receiver or to regular stereo if this feature is not available. This imposes the normal restrictions to Prologic including mono rear channels and no discrete sub woofer channel. If you get a DVD player before you upgrade your sound system this is the way you will have to connect the system. These output and input jacks are color coded with white for the left channel and red for the right. (just a note, the yellow jacks are for the video.)
RF digital audio (LaserDisc only):
This type of connector is becoming extinct due to the growing popularity of DVD as the serious movie collector's media of choice. It uses a coax cable to from the output of the laser disc to the LD/DVD input of the receiver. It is important to remember that the digital audio from a DVD does not come out of the RF output but is only outputted from the optical output. This output is only analog and will require three separate audio hookups to cover all the variations. Please note, DVDs do not output in RF format so you will need an autoswitch capability. The consensus for this approach is 'why bother'.
Just as important as the audio for DVD is the video. In most cases there many be less actual choices than show here due to limitations on your TV's connection abilities. In any case, here are the standards.
HDMI (High Definition Media Interface) (best)
This is the latest in high definition video cabling. It is now common on Blu-ray DVD players, HD Cable boxes, HD DVRs and most types of high definition television sets. The cables are built to very exacting specifications and require high quality materials so they tend to be expensive. For the picture quality this cable is unmatched and well worth it. The most common form of this cable is the Type A connector. This is has 19 pins and supports the SDTV, EDTV and HDTV formats. There is a Type B with 29 pins on the horizon but it is not in use as of yet. It has a bandwidth of 1080p at rates up to 120 Hz. HDMI 1.3 as used in modern Blu-ray players can transport DD+, TrueHD, and DTS-HD bitstreams in compressed form. Less expensive models can have a length of about 16 feet while better made cables can go up to about 40 feet but cables of that length will cost you. For example a 25 foot cable can run over $200 while you can find cables of 12 feet for around $60 to $100. Considering you most likely just spent three to four thousand on that plasma TV, Blu-ray DVD and home theater receiver go for a higher quality cable. You might as well see all the high definition video that you paid for. As these cables become more common in use the prices should go down.
Progressive video (little better still):
Players have been produced with progressive-scan YUV component video output in the form of 3 BNC or RCA connectors. Hook decent-quality cables from the three video outputs of the player to the three video inputs of a progressive-scan line multiplier or a progressive-scan TV. Toshiba's version is called ColorStream PRO. This format preserves the progressive nature of most 24-frame movie discs, providing a film-like, flicker-free image with higher vertical resolution and smoother motion. Until recently, this was restricted to computers since there are numerous copy protection problems. Now, many new televisions and DVD players are supporting this mode. Rather than painting the image with alternate lines, odd lines of the picture first followed by the even lines, the progressive scan pushes the entire picture to the screen. This greatly reduces the flicker. For more advanced details please click here.
Component video (better):
Some U.S. and Japanese players have interlaced component YUV video output in the form of 3 RCA or BNC connectors. Connectors may be labeled YUV, color difference, YPbPr, or Y/B-Y/R-Y, and may be colored green/blue/red. Some players have RGB component video output via a 20-pin SCART connector or 3 RCA or BNC connectors labeled R/G/B. Hook cables from the three video outputs of the player to the three video inputs of the display, or a SCART cable from the player to the display. Note: For equipment with RGB inputs, the YUV signal won't work; a transcoder is required. It may be possible to obtain a converter to obtain component video from another format such as S-video. Be cautious since this is outside most design specifications and the quality may be compromised. The typical color codes for this connector set are: Green (luminance), Blue (Pa B-Y) and Red (Pa R-Y).
S-video (above average) :
Almost all players have s-video output. Hook an s-video cable from the player to the display (or to an A/V receiver that can switch s-video). The round, 4-pin connectors may be labeled Y/C, s-video, or S-VHS.This four pin connector provides superior video than the RCA connectors for two reasons, greater bandwidth and segregation of the signals.S-video, Super VHS, SVHS, Hi-8 and other "Y/C" formats use two separate video signals. The luminance (Y) is the black and white portion providing brightness information. The chrominance (C) is the color portion providing hue and saturation. The remaining two pins are grounds. With the typical RCA cable all video information is contained in one cable. This increases cross talk or overlap of information from one signal to an other. For a little more advanced definition click here.
Composite video (average):
All DVD players have standard RCA (Cinch) baseboard video connectors. Hook a standard video cable from the player to the display (or to an A/V receiver ). The connectors are usually yellow and may be labeled video, CVBS, composite, or baseband. Very often this jack is found next to the two for the audio, red for right audio and white for left audio.
RF video (worst):
A few players have RF video output for televisions with only an antenna connection. Connect a coax cable from the player to the TV. A 300 ohm to 75 ohm adapter may be needed. Tune the TV to channel 3 or 4 and set the switch on the back of the player to match. Audio is supplied with the RF signal, but it's only mono, even on stereo TVs. If you have a player without RF output, you can buy an RF modulator (~$30) to hook up to an old TV that only has RF input. If you try to hook up your DVD through your VCR you can run into problems on discs protected with copy protection such as Macrovision in place. In February 2009 television broadcast will be only in digital and a converter box running about $50 will be required to use this type of connection. this conversion to digital will not affect people using cable or satellite TV.