Technical FAQs

Find the answers to many of the Frequently Asked Questions on Home Theater Systems, DVDs, Speakers etc. in our Tech FAQ. If you don't find the answer to your particular question or if you need further information regarding any of the answers listed here, just send us an e-mail and we will be more than happy to answer your questions.

• Home Theater FAQ
• DVD FAQ
• Speakers FAQ
• Hard Disc Video Recorder FAQ
• Accessories FAQ
• Power Protection FAQ
• Home Networking and WLAN FAQ
• Glossary

Home Theater FAQ

Q: Why Home Theater? What are the benefits?
A: The primary goal of a home theater is to bring the experience of a theater to your home. You can bring big screen pictures and digital surround sound to your living room with a clarity and fidelity never before possible and see details you never noticed before. Pictures will be so life-like they will almost pop off the screen. Dolby Digital and DTS audio will provide a surround sound experience that will put you right in the middle of the action.

Q: What are the minimum requirements for a home theater system?
A: There is no absolute definition of what constitutes a home theater system. However, most people agree that a respectable home theater should, at the bare minimum, consist of a 27" TV, VCR / DVD player, receiver and a surround sound speaker package.

Q: What is meant by 5.1, 6.1, and 7.1?
A: With respect to home playback, the terms 5.1, 6.1, and 7.1 mean that there are five, six, or seven main speakers, plus a subwoofer, in the playback system. (The subwoofer reproduces the LFE channel recorded on 5.1 soundtracks, plus any bass the main speakers cannot handle.) The difference is in the number of surround speakers: two in a 5.1 system, three in a 6.1 system, and four in a 7.1 system. Obviously, a 5.1-channel soundtrack can be played on a 5.1-speaker system. But it is not always understood is that it can also be played on a 6.1- or a 7.1-speaker system. To do this, the two surround signals on the 5.1 soundtrack are spread across the three or four surround speakers. This distribution can be accomplished by a Dolby Digital EX decoder, a THX Surround EX decoder, or other proprietary methods provided in home theater equipment by various manufacturers.

Q: What is THX?
A: For home theater, THX is a trademark that identifies home theater components such as sound processors and speaker systems that comply with performance parameters of Lucasfilm THX and/or feature their proprietary playback processes. These processes are applied to the signal after Dolby Pro Logic or Dolby Digital decoding, and are intended to produce a listening experience more like that of dubbing theaters where movie soundtracks are mixed.

Q: What's the difference between Dolby Digital and DTS?
A: Dolby Digital and DTS are similar in that they are both digital lossy audio coding technologies, which means they use “perceptual” data reduction techniques that are based on the characteristics of human hearing to mask the process, thereby preserving high fidelity sound. This is necessary in order to fit the typical 5.1-channel bitstream into a given storage space or transmission bandwidth. Beyond those basic similarities, the two formats are very different. The main difference is that Dolby Digital is designed to handle anything from mono to full 5.1-channel sound formats, and typically runs at data rates of 192 to 448 kbps depending on the number of audio channels and the application. DTS was originally designed for a data rate of 1411 kbps, and typically runs at data rates of 754 or 1509 kbps depending on the data capacity available. In order to achieve lower data rates than DTS with no sacrifice in sound quality, Dolby Digital uses many sophisticated data reduction technologies that DTS lacks. The most commonly used data rate for Dolby Digital on DVDs has increased to 448 kbps, thus assuring optimal sound quality. Meanwhile, DTS data rates have been cut in half for most new DVDs, down to 754 kbps, potentially decreasing sound quality. There is some debate about which of the two formats is better. Obviously, we at Dolby feel our technology is superior, and we are proud to say that the electronics and broadcast industries seem to agree. After exhaustive listening tests, Dolby Digital has been chosen as the standard for digital broadcast television, digital cable, and digital satellite TV in almost every country worldwide. All DVDs in the U.S. (and worldwide) are mandated to carry either Dolby Digital or PCM stereo audio. Finally, Dolby Digital is by far the leader in commercial cinema; it is installed in more than 30,000 theaters worldwide

Q: What’s the best type of speakers for a home theater?
A: For best results, we generally recommend that the five main-channel speakers (left, center, and right front speakers, plus the two surrounds) be the same. At the least, all speakers should come from the same manufacturer and be designed to provide similar tonal characteristics, or timbre.

Q: What is Dolby Digital Surround EX?
A: Dolby Digital Surround EX was first introduced in cinemas with the release of Star Wars: Episode One—The Phantom Menace. The EX format features a third surround channel for playback at the cinema's option over surround speakers located behind the audience, while the left and right surround channels are reproduced by surround speakers to the sides. To maintain compatibility, the back surround channel is matrix-encoded onto the left and right surround channels of the 5.1 mix so that no information is lost when the film is played in conventional 5.1. Surround EX soundtracks are now also found on the DVDs, and a/v receivers are available with either THX Surround EX or Dolby Digital EX decoding to derive the extra surround channel. As with EX films, DVDs with EX encoded soundtracks can be played in conventional 5.1. The benefits of Surround EX include more realistic flyover and fly-around effects, a more stable image for atmospheres and music, and a more consistent surround effect throughout the auditorium or home viewing area

Q: What is the difference between Dolby Surround, Dolby Pro Logic, Dolby Digital 5.1 and DTS 5.1? Is one better than the other?
A: Dolby Surround involves encoding four channels of information - Front Left, Center, Front Right, and Rear Surround into a two channel signal. A decoding chip then decodes the four channels and sends them to the appropriate destination, the Left, Right, Rear, and Phantom Center (center channel is derived from the L/R front channels). The result is a more balanced listening environment in which the main sounds derive from the left and right channels, the vocal or dialog emanates from the center phantom channel, and the ambience or effects information comes in from behind the listener.

Dolby Pro-Logic adds hardware elements in the decoding chip that emphasize important directional cues in a movie soundtrack. This process, although not important in musical recordings is very effective for film soundtracks and adds more accuracy to effects such as explosions, planes flying overhead, etc. There is greater separation between channels. In addition, Dolby Pro-Logic extracts a dedicated Center Channel that more accurately centers the dialog (this necessitates a center channel speaker for full effect) in a movie soundtrack.

Dolby Digital adds both accuracy and flexibility by adding stereo rear surround channels that enable sounds to emanate in more directions, as well as a dedicated Subwoofer Channel to provide more emphasis for low frequency effects. Dolby Digital is often referred to as a 5.1 channel system, because of the added Subwoofer channel. Also, unlike Dolby Pro-logic which requires a rear channel of only minimal power and limited frequency response, Dolby Digital encoding/decoding requires the same power output and frequency range as the main channels. Dolby Digital encoding on DVDs, Laserdiscs, and Satellite programming is very common and has solidified this format in the marketplace. Since Dolby Digital involves its own encoding process, you need to have a Dolby Digital receiver or amplifier to accurately decode the signal.

Digital Theater Systems (DTS) has also adapted its surround sound process for home use. It is a 5.1 system just like Dolby Digital, but since DTS uses less compression in encoding process, many feel that DTS has a better result on the listening end. In addition, while Dolby Digital is mainly intended for the Movie Soundtrack experience, DTS is being used in the mixing and reproduction of Musical performances. Many CD-only players now come equipped with DTS outputs that allow a DTS-equipped amplifier or receiver to decode the DTS signals imprinted on "select" DTS-encoded music CD's

Q: What's Dolby Digital-EX ,DTS-EX, and THX-EX?
A: Dolby Digital-EX and DTS-ES add a rear center channel to the typical 5.1 surround setup to make it 6.1. THX-EX is the processing technique to match the new soundtracks

Q: What is the difference between composite, S-video, component and RGB video?
A: Composite video is standard on all DVD players. You 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.

A better solution is S-video. Almost all players have s-video output. S-video looks much better than composite video, and only slightly inferior to component video. 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 labelled Y/C, s-video, or S-VHS.

Component video is the best solution: Most DVD players have interlaced (some also have progressive scan) component YUV (Y'Pb'Pr') video output in the form of 3 RCA-jack connectors. Connectors may be labeled YUV, color difference, YPbPr, or Y/B-Y/R-Y, and may be colored green/blue/red. (Some players incorrectly label the output YCbCr.) Some DVD players and HDTV receivers also have RGB component video output via a 15-pin video plug (similar to a monitor on your PC).

Q: Can I mix composite, s-video, component and rgb video when hooking up my system?
A: This varies depending on the equipment. It depends if your receiver or TV has the capability to perform video format conversion. Most do not. For example, if you hooked up your VCR to your receiver with composite video cable, you could not then, hook-up your receiver to your TV with s-video cables. However, your best bet is to consult your owners manual for specifications on your equipment.

Q: What is the difference between interlaced and progressive video?
A: An interlaced picture is divided into two halves, the odd and even scan lines. These are "halves" are displayed odd, even, odd, even, etc., at a rate of 60 frames per second. So, in reality at any given time you are only seeing half of the picture (although because the frame rate is so high, your eyes don't notice it.) Interlaced scanning sometimes results in screen flicker and visible scan lines. Standard analog TV signals are interlaced signals.

Progressive scanning takes the whole picture (all scan lines) and displays them at a rate of 30 frames per second. Because the whole frame is reproduced every time, the result is a more solid, film-like picture. Computer monitors use progressive video.

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DVD FAQ

Q: What does "DVD" stand for?
A: DVD once stood for digital video disc or digital versatile disc, but now it just stands for DVD -- the next generation of optical disc storage technology. DVD is essentially a bigger, faster CD that can hold cinema-like video, better-than-CD audio, and computer data.

Q: How would I connect a DVD player to my TV to get the best possible picture?
A: That will depend on the type of input available on your TV. Here are three possibilities, starting with the highest quality connection:

Component video: This 3-jack connection will provide the ultimate in color accuracy, and more and more DVD players are including it. TV manufacturers have been slower to include a matching component video input, but it's now available on several models we sell.

S-video: Every DVD player we've seen has at least one S-video output, and most current mid- to higher-priced TVs have at least one S-video input. This connection yields superb picture quality — nearly as good as component video — but colors may not be quite as vivid and free from bleeding.

Composite video (RCA jack): Virtually all DVD players and current mid- to upper-priced TVs include an RCA-type direct video input. A slight step down in overall sharpness and color accuracy from S-video, but still very good.

Q: Do I need a Dolby Digital receiver to enjoy home theater surround sound with DVD?
A: No. All DVD players have regular right and left stereo analog output jacks. Connect them to an A/V receiver with Dolby Pro Logic or Dolby Surround for surround sound, or to a stereo receiver for 2-channel stereo sound. If your DVD player has its own built-in Dolby Digital decoder and 5.1-channel analog outputs, you can connect it to a "5.1-ready" receiver and enjoy full Dolby Digital surround sound.

Q: Can a DVD player play my music CDs? And if so, will it sound as good as my CD player?
A: DVD players are "backwards-compatible" with CDs — they'll play them perfectly! A DVD player's advanced disc transport and digital-to-analog converters are designed for the demanding task of reading and processing the huge amounts of audio and video information on DVDs. By comparison, playing a music CD is a piece of cake. Based on our experience, DVD players sound better than most CD players. And magazine reviews have generally described the CD audio performance of DVD players as "outstanding."

Q: Why do movie studios sometimes include multiple screen-aspect versions of a movie on a single DVD disc?
A: The short answer is, because they can. Double-sided discs and dual-layer discs offer enough storage capacity to include a version formatted for a standard TV, as well as a "letterbox" or other widescreen version. Widescreen versions are preferred by many film buffs and videophiles because they keep the director's original vision intact.

Q: Can I use my VCR to record off DVD?
A: Probably not. All DVD players include an anti-copy circuit which will distort the picture if your VCR includes the corresponding circuit (Macrovision or something similar). In fact, you may not be able to have your VCR connected between your DVD player and your TV, even if the VCR is not recording! You should probably connect your DVD player directly to your TV.

Q: What are "regional codes," "country codes," or "zone locks"?
A:The movie industry insisted that the DVD standard include codes which would limit playback to a specified geographical region. This was done because theater and home video releases of movies do not occur simultaneously worldwide. For example, a movie may be released on video in the U.S. just as it's first appearing in theaters in Europe. DVD players have a built-in region code lockout feature, while the DVD discs may or may not contain a code (region codes are optional on DVD software). A player will be unable to play a disc that has a different region code. Discs may contain codes for more than one region, or may not have any code, which allows them to be played on any player in any country. The region code for Indian subcontinent is "5".

There are 8 regions (also called "locales"). Players and discs are often identified by the region number superimposed on a world globe. If a disc plays in more than one region it will have more than one number on the globe.
1: U.S., Canada, U.S. Territories
2: Japan, Europe, South Africa, and Middle East (including Egypt)
3: Southeast Asia and East Asia (including Hong Kong)
4: Australia, New Zealand, Pacific Islands, Central America, Mexico, South America, and the Caribbean
5: Eastern Europe (Former Soviet Union), Indian subcontinent, Africa, North Korea, and Mongolia
6: China
7: Reserved
8: Special international venues (airplanes, cruise ships, etc.)

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Speakers FAQ

Q: What's the difference between a subwoofer/satellite system and a conventional speaker system?
A: A subwoofer/satellite system is a room-friendly, space-efficient alternative to the conventional stereo speaker system. Sub/sat systems use small enclosures for the tweeters and midranges, and a separate, specially designed box to house the woofer(s).
Subwoofer/satellite systems are very popular because they save space, blend into the room's decor, and offer full, rich sound. The bass module can be placed almost anywhere because it produces only low, non-directional bass frequencies.

Q: Can I hook up a powered subwoofer if my receiver doesn't have a subwoofer output?
A: Absolutely. Almost all powered subwoofers have speaker-level connections for use with virtually any receiver. Just run one set of speaker cables from your receiver's main left and right speaker outputs to the subwoofer, then another from the subwoofer to your main left and right speakers (you'll need an extra pair of speaker cables).

Q: Can a pair of satellite speakers and a powered sub really sound as good as a pair of larger speakers?
A: Definitely. In fact, there are some folks who prefer a sat/sub system because small satellite speakers excel at imaging. To get the best sound from this type of 3-piece system, it's important to choose satellites and a subwoofer that blend well together sonically.

Q: What is matching?
A: A speaker's impedance rating refers to the amount of electrical resistance it presents against current flowing from your amplifier or receiver's powered outputs. Though impedance actually fluctuates as the speaker reproduces different frequencies, manufacturers usually publish a single, average figure, known as nominal impedance.

Most home speakers have a nominal impedance rating of 8 ohms; likewise, most home A/V receivers are designed to be stable when pushing an 8-ohm load. Speakers with significantly lower impedance (4 ohms or less) may cause problems with these receivers by asking them to deliver more current than they are capable of producing.

When you drop from an 8-ohm to a 4-ohm load, you cut the electrical resistance in half, which usually causes your receiver to increase its total power output. Some people are tempted to mate their 8-ohm receivers with 4-ohm speakers, in order to get more wattage. It's wise to avoid this temptation, since it can lead to greater distortion, and cause the receiver to run hot or activate its protection circuitry

Q: What does a speaker's sensitivity rating tell me, and why is it important?
A: A speaker's sensitivity rating (sometimes called efficiency) tells you how effectively the speaker converts power into sound. The higher the number, the more efficient the speaker, and the louder the sound it creates with a given input signal.

An efficient speaker helps you maximize your available wattage. Believe it or not, a 3 dB increase in speaker sensitivity produces the same audible increase in volume as doubling your amplifier power! So when you're shopping for speakers, it always pays to check the sensitivity spec — especially in low-wattage situations.

It's a common myth that larger speakers require tons of power and smaller speakers can get by with minimal wattage. In fact, the reverse may be true — some of the smallest speakers we sell are actually pretty power hungry, while larger speakers can be quite efficient

Q: What are dipolar, bipolar and monopole speakers?
A: Dipolar refers to speakers with drivers that are fired in two different directions and are in reverse phase causing a cancellation of sound waves in front of the speaker. This is usually done in rear speakers that are wall mounted. The front of the speaker is aimed at the listening area, which causes all of the sound to bounce off the walls before it is heard. This makes it almost impossible to determine where the speaker is, creating a true surround effect.

Bi-polar refers to speakers with drivers that are fired in two different directions, but are in phase causing an increase in bass output. I this type of speaker the drivers can be in the front and back of the speaker, side firing, or at 90º angles from one another. There are also speakers which function as both bipolar and dipolar. This can be adjusted using a switch.

Monopole is a type of speaker with all drivers facing one direction. Used for precise placement of sounds. Usually used in front and center speakers

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