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Dolby, DTS, Digital, Surround Sound, THX what does all this mean?
These terms refer to the various multichannel sound formats or encoding systems used to produce the realistic 'soundstage' necessary to recreate the movie experience.
In essence, each format encodes audio signals meant to surround the listener to provide a realistic re-creation of the 'sound stage' created for the movie audience. In particular, the dialogue in the movie is directed to a speaker placed directly atop or in front of the video screen; other sounds, music, effects, etc., are 'mixed' or directed to speakers placed elsewhere.
One issue with differing formats is the same old one - incompatibility. Fortunately, many home theatre receivers decode several different sound formats, so the home theatre buyer doesn't have to choose; you can have it all!
What type of systems are available?
Like automobiles, there's a home theatre system to fit your needs and your budget. Basic HT systems consist of a televison or video monitor, HT receiver, DVD player and speakers. More elaborate systems may include video projection systems, separate preamp/processor - power amplifier combinations, and speakers of hundreds of types.
The best way to approach home theatre is to see a demonstration system, and answer some basic questions about your dream system. For example, what is your budget? Will you remodel a room for the installation? How big an image do you want? With the answers to these questions, you and your installer can design the system together, and create a home theatre system within your budget that meets your needs.
How flexible can a system be?
Even the basic HT system's flexibility is limited only by your imagination. HT systems can be the nucleus of multi-room audio/video systems, delivering high-quality sound and video throughout the home. Many sources of program material are available, including cableTV, satellite TV and audio, direct broadcast TV, and the several sound formats such as CD, DVD-Audio and others.
Today's home theatre systems are certainly 'backward compatible'; you can play your treasured cassettes, LPs and other media through the system and hear them in conventional two-channel stereo, or spatially enhanced via the digital sound processor in the HT receiver. This processing capability can also be used to 'clean up' hissy recordings, and produce bass effects missing in your original recordings.
How much does it cost?
A basic system consisting of a 32" direct-view CRT televison, DVD player, HT receiver andspeakers can cost under $2000. The interest in home theatre has yet to peak, and designers and home owners have created systems costing well in excess of $200,000! Realistically, many people view their home theatre as the place to relax and unwind after a stressful day. So costs are proportional to your desire for comfort, and your appreciation of the experience finer components and installations can deliver.
Why shouldn't I just buy a surround system from the
local electronics store?
Of course this is an option; however, if your goal is to create a pleasant and inviting environment, custom installation allows you to integrate the system with your decor. Speakers can be built into walls, electronic components can be conveniently rack mounted and enclosed, and wires running across carpets can be a thing of the past.
As your needs become better understood, custom installation opens the door to possibilities and components you won't find in the local hi-fi shop. Remote speakers and infrared repeaters expand the boundaries of the system, and the array of audio and video components available for custom installation ranges from high-definition DLP projectors that create huge 'windows' with startlingly realistic images, to integrated remote control consoles that eliminate the coffee-table clutter of the many remote controls.
With greater sophistication comes greater complexity; stress is the inevitable result. The process of assembling a high-end home theatre system can be lengthy and complex. Again, the car analogy: whereas a generation ago, you might do your own tune-ups, today's cars demand professional attention. A home theatre should deliver enjoyment and relaxation, and a professional installation is the surest first step toward achieving those goals.
I have a limited budget, what are the basics? Can I expand?
The basics are: a source of program material, a video display, and a sound system. These components may be highly integrated, such as the portable DVD player/LCD video units, or separated into many functionally specific units tied together, as most large custom-designed systems are. Although any system can be expanded, components have built-in limitations that eventually limit their expandability.
The most basic system is your TV and a DVD player. Not really a system at all, but at least you can enjoy DVDs or satellite or cable broadcasts. A key consideration here is the software: all the hardware in the world can't create program material. So, your choice of A/V programming has to be considered at the beginning.
Since the video unit is the central feature of a home theatre system, its selection deserves the most careful consideration, and usually, financial outlay. Your choice of display may determine many other choices: room size, theatre design, lighting, seating and sound system design and capability.
The next item is the audiovisual, or AV receiver. This highly integrated and complex unit performs several functions required to deliver the theatre experience and integrated your components into a system:
1. The receiver converts the digital bitstream, or signal, from the DVD player, to the analogue signals required by the video display, or TV and the speakers.
2. It decodes the multichannel sound components from the audio signal according to its encoding scheme, i.e. Dolby Digital, DTS, Dolby THX etc. This decoding provides the various sound sources required to deliver a realistic sound stage: centre channel, right and left front channels, right and left rear channels, and subwoofer. This is the basic five channel plus sub, or 5.1 channel arrangement. Variations include 6.1 and 7.1 systems, providing more rear-of-the-room sound sources.
3. It processes the audio, usually digitally, to optimize it for your room or your tastes. These processes include equalization, reverberation, time delay and spatial positioning.
4. The power amplifiers in the receiver each drive their own loudspeakers independently.
The receiver usually performs other functions such as signal switching and routing.
As you may have guessed, all of these various functions performed by a single component, the A/V recevier, are available in separate components. The most common 'split' is the preamp-processor or pre/pro, which requires external power amplifiers.
The speakers are the the last step in the audio/acoustic chain, and serve to couple the electronic audio signals to the acoustic environment in the room. This coupling is the single most widely varying and poorly understood item in home theatre design, and ultimately depends completely on your listening preferences. Those preferences are what you have developed in a lifetime of audio experience, and what will deliver the satisfaction you should experience in a system which is right for you.
What is more important, a good amp or good speakers?
Short answer: the speakers that sound best to you, driven by the best amp you can afford with the money left after you buy your speakers.
The speakers, coupled with the room they are in, along with their placement have the most influence on the sound you hear from your system. They range in design from simple and unchanged for decades, to stunningly complex, technologically advanced units with similarly stunning prices. The interactions between listener and loudspeaker can and do fill volumes of text, yet can be reduced to the simplest of rules: buy the speakers that sound good to you. If you understand the interactions between speaker placement and room acoustics, you can tune your system and achieve the sound you want. A dealer willing to work with you until you get the sound you want should have an exchange policy that can cope with the fact that speakers sound different in different rooms. In particular, speakers that sound fine in the dealer's showroom may simply not work in your listening room.
Having selected the speakers you want, the choice of amplifier is easier: home theatre receivers come in several different power ratings, and unless your speakers are particularly power hungry, there's an AV receiver that can do the job. Those with generous budgets for components can take advantage of several very powerful HT amplifiers with great sound, but even relatively modest systems can create heart-pounding special effects.
Above all, take the past of least resistance when selecting components. Despite high-pressure sales tactics and conflicting advice, take your time, stick to your vision and listen to as many systems as you can. Your first HT purchase can be a favourite movie on DVD that you take to the showrooms, or play every time you audition a new speaker or other component.
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