Aug 1, 2003 12:00 PM, Isaac Saboohi
Home theaters and distributed A/V systems have increasingly become an integral part in designing a home. The majority of new house construction includes the infrastructure for a home theater and distributed A/V system along with the structured wiring. The future is bright for this market because there is an explosion of new technology, and consumer demand exists to back it up. Long-term implications are the possibility of up-sale in three years' time when the transition is complete to HDTV, which gives dealers an opportunity to sell and upgrade their customers' systems and possibly turn that spare room into a home theater.
The home-theater market has evolved since 50-inch TVs were first introduced, with more products and choices available at a fraction of what they used to cost. The introduction of affordable DVD players and components brought the dream of having an entertainment system and distributed A/V systems to the masses. In addition, technological advances have made way for products that not only perform optimally but are also intuitive and user-friendly. The marketplace is competitive, so providing a one-stop solution can help win more business.
Many things must be considered when designing a home-theater system, and fortunately, there are enough choices available to meet any individual's entertainment needs and budget. Following are some basic factors to consider when designing a home-theater system. (Because regulations vary from state to state, be sure to follow local building codes.)
Whether it's in an existing structure or new construction, building a home-theater system involves the cooperation of many disciplines. You'll have to coordinate with the cabinetmaker to ensure that his or her design will house the equipment properly and provide adequate access, cooling, and facilities for cable management. Communication with the electrical contractor is key to making sure the electrical outlets and switches are conveniently located, and you might have to work with a designer to integrate the prime visible components into the aesthetics of a room.
If your client doesn't live in the middle of a five-acre plot, you need to consider the neighbors and take proper steps for noise control. The primary goal is to provide isolation. Double walls, staggered studs (see Fig. 1), or special insulation and materials will provide for better isolation from room to room as well as indoors to outdoors. One of the most effective methods is to use double walls, which are two walls that are completely detached from each other (see Fig. 2). That is usually the best option if the existing walls are constructed of drywall. You can run the electrical and low-voltage wiring between the two walls without piercing through the drywall and damaging it.
Fill in all around doorjambs, holes, HVAC ducts, and outlets with acoustic caulk. Regular batt insulation can be used in between staggered walls if there was no existing drywall. If there is drywall, a blown insulation such as Optima is recommended in the second wall. A blown insulation will form a tight seal around holes and cavities and will conform to the walls. The added insulation will benefit the thermal characteristics of the room, as well.
It is important to realize (especially when using in-wall loudspeaker systems) that walls have a resonant frequency. The addition of a loudspeaker will turn the whole wall surface into one big transducer (see Fig. 3). The worst case is that bass response can be negatively affected, resulting in a system that sounds muddy or tubby — so make sure the walls are as rigid as possible.
Electrical and low-voltage wiring
Carefully consider the placement and layout of the system in the room. To help prevent distortion and hum through the system, provide dedicated electrical circuits for the theater. Make sure there is sufficient AC to support all amplifiers and other equipment. Provide an outlet where the video projector or display will be installed.
Now that you have dealt with the sound traveling out of the room, it is time to deal with the sound in the room. The idea is to have a combination of reflective and absorptive surfaces in the room. A good rule of thumb is that about 25 percent of the room should be covered with absorptive materials. Panels can be covered with acoustically transparent fabric to match any decor or fabric and can be pulled over the whole acoustic treatment system for a completely discreet look. All absorptive panels should be at least 2-inch-thick fiberglass to be effective down to 500 Hz.
PRODUCTS AND TECHNOLOGIES
The market has no shortage of consumer A/V equipment. A custom electronics integrator provides guidance and information as to the best product to use for a particular situation — that's what sets them apart from the retail establishment.
Incorporating video scalers into the system will ease the installation process as well as make your customers happy. There are many high-quality scalers in the market today. Faroudja and Focus Enhancements manufacture systems that provide good functionality for a home theater. Focus Enhancements' CenterStage CS-2 video processor provides multiple inputs to connect all your components, and it has one RGB HV cable that connects to your projector or monitor. The CenterStage CS-2 has independent settings for each of the inputs, which means that when you are switching from satellite to DVD, no other adjustments will need to be made. All of the input and output adjustments are independent and stored in memory, so when you switch to satellite, the images look the way they are intended to look, without the noise and flicker lines. It accepts digital video interface (DVI) from an HDTV receiver and has DVI with HDCP digital output to your monitor. The Faroudja DVP-1000 offers similar features, as well.
Satellite systems can have image quality rivaling DVDs. When it is streamed down, it is in MPEG form, which is the same compressed digital stream that DVDs use. Once the content reaches the satellite box, it is uncompressed and decoded to play on your TV set. New HDTV satellite boxes such as the Samsung SIR-TS160 have components outputs and can also upconvert regular NTSC programming to 720p.
When specifying a rear-projection TV, look for one like the Hitachi or Toshiba CinemaVision, which has a 720p input. That way you'll have less motion artifacts, and your scaler can process satellite and NTSC images to 720p and output them to the set for the best results. Although 1,080i looks amazing with static images, when you try to watch sports on it with a lot of movement, you'll see motion artifacts.
The back wall should be a matte neutral gray or black for front-projection systems. Light that is reflecting off the screen can bounce off the back wall and distort the projected image. Paint behind and around the screen matte black, as well.
A variety of control systems are suitable for certain applications, but the most important thing is to design the system in such a way that even grandma can pick up the remote and tune to the Disney Channel for the kids. Therefore a good learning remote is a must. The RTI T2 is an ergonomic, easy-to-use remote control that's hard to pass up, especially if your client is on a budget.
Your client will be able to set up complex macros. He or she can program the remote so that one button will dim the lights, turn on the surround processor, and choose the correct input from the scaler. There are also optional sensors that monitor the status of the equipment and keep the components in sync with each other.
The budget and the application of the system will determine what type of audio processor is needed. Receivers are commonly used for home-theater applications. They range in price from $400 to $4,500. Make sure the one you get has enough inputs and outputs to cover all your present component requirements, as well as a few extra for future equipment additions or system expansion.
The receiver will do the majority of the A/V switching, so you need to make sure that it does not degrade the video and that it has enough bandwidth to pass HD. Look for something that operates at 50 MHz and above. Most current model receivers are capable of upconverting the video signal, which is useful if there is no way to spec in a video processor for the job. They convert composite and Y/C to component. That gives you the ability to run a component signal for all your sources to the TV through one cable. The benefit is that monitors will usually have a basic scaler built in for the component input. The images are then converted to progressive, and you'll see a slight improvement of the picture. Also take note that if the receiver is not upscaling the image to the native resolution of the set, it will still remain at 480i.
Receivers are easy to set up; they have everything that you need for a basic to midlevel system, and they offer a lot of value for the money. Receivers without a beefy power supply will greatly reduce the headroom of the system, and the sound will seem compressed during the dynamic scenes. Also make sure that your receiver has discrete infrared codes for each input and on/off, otherwise you'll run into a hurdle during integration and programming. Denon offers professional receivers with high overall performance. The company's flagship AVR-5803 comes close to achieving separates-level quality in a receiver. However, there are definitely trade-offs in performance and control when you are combining all the processing, amplification, and video circuitry into a single unit. The only way to have complete control is to use separate components.
Separates will offer a lot more control and greater fidelity. Besides the benefit of having the audio, video, and amplification isolated from each other, separates have other pluses. One is the ability to add room tuning processors and equalizers to help compensate for some of the acoustical properties of the room. That way everything is more tailored, and great end results can be attained. A few companies offer room-correction-based parametric equalizers and processors, including Snell Acoustics, JBL Synthesis, AudioControl Diva, and Lexicon.
A music management system really makes searching through disks and songs a breeze. It will manage your whole music collection, and it has a graphical interface that can be displayed on a monitor or touch screens for music searching. AudioReQuest is the leader in digital music servers. Advanced integration and networking features make AudioReQuest Fusion a killer application for multiroom, multisource, and multilocation A/V systems. ReQuest Multimedia is well-known throughout the industry for its high level support of both product and integration into high-end A/V installations.
The final step entails the calibration and alignment of the both the video and audio systems. Proper alignment of the systems is essential for the system to operate optimally and efficiently. There are a variety of tools and services available to the custom electronics integrator. The Imaging Science Foundation, founded by Joe Kane and HAA, provides training on the standards and achieving quality images from their screening rooms and theaters.
Equipment and software for audio analysis to consider are the Sencore SP 295, room mode, and real-time analyzer. ETF 5 from Acoustisoft is a software-based 2-channel resolution measurement system that runs on a laptop with a sound card. The software is reasonably priced and not complicated to operate. Smart Live and Acoustic Tools from SIA Software Company is a comprehensive set of software tools for measurement, analysis, and system alignment.
For video calibration, Sencore also manufactures the CP 5000 color analyzer to set up gray scale on CRTs and fixed pixel devices. A versatile and extremely useful set of tools is the new Digital Video Essentials calibration tools by Joe Kane Productions. They are inexpensive and readily available. They also include a tutorial that walks you through the setup and calibration procedure of your audio/video system.
Isaac Saboohiis the owner of XTCsound Systems based in Studio City, California. XTC designs and integrates systems for home theaters, distributed audio/video systems, home automation, control, phone, and lighting.