Hopefully, the sound from the audio or home theater systems you put in the homes you build is coming from the right places.

An increasing number of builders are integrating speakers into their residential structures, especially in the form of in-wall or in-ceiling speakers. And, while speaker installations are often done by a professional electronics integrator, it is still valuable for builders to understand how the decisions are made concerning where to place them.

To understand best speaker placement, builders need to have a basic understanding of acoustical theory, topographical placement, and how the substructure of a room affects the audio experience.

Just as important as the material used in the construction of the speaker itself, the placement and the way a speaker is installed and secured to the framing will affect how it performs. Your integrator is most likely the one who will design around the room space to determine audio high spots and low spots and to determine audio dispersion, but knowing the process the integrator goes through to provide the best acoustics can help you in the framing and construction process before they start their role.

Speaker Mechanics

Ever since 1924 when C.W. Rice and E. W. Kelley invented the first loudspeaker using a solenoid and cone arrangement, manufacturers have been discussing and arguing the best material and component assemblies for making speakers. Electrostatic loudspeakers today are basically motors connected to a diaphragm or cone that drives air in acoustical waves into the listening environment. The motor is driven by an electromagnet that modulates or vibrates the diaphragm when energized by electrical signals from the amplifier, which in turn creates the acoustical wave that we detect as sound.

Here are five considerations for builders to address when incorporating in-wall and in-ceiling speakers when related to new construction. The advice comes from Mike Musgrave, operations manager at Audio Video Entertainment (AVE) in Laguna Niguel, Calif., which installed over 3,000 entertainment networks in new homes in 2004.

1. Leave It To the Pros—This advice is self-serving, but as Musgrave points out, professional installers and integrators can often receive substantial discounts on equipment and pass some of the savings on to you. Beware, this does not qualify them to predict performance or to understand all the subtle nuances of audio. Make sure your subcontractor has the industry and state certifications that qualify them. Furthermore, make sure the company has any necessary insurance and service contracts, and that they can service all the aspects of this technology.

2. Measure Twice, Cut Once—Yes, the general builder's code applies here. Plan your speaker cut-outs carefully, then double check your locations. Design the framing space or cavity so that they are a uniform 14.5 inches wide, and that the spaces where the speakers are to be placed are equal in cubic volume. If two or more speakers are expected to sound the same and have the same dispersion patterns, then the cubic volume of the area behind each must be equal.

3. Let There Be Light—When lighting cans are integrated, make sure that they are installed correctly and will not vibrate or resonate, and that the architectural sight lines complement the speaker placement.

4. Take It Back—One of the most beneficial things that a builder can do when incorporating speakers into residential structures is to have the integrator install "back boxes." A back box is an enclosure that, like many of the traditional stand-alone speakers, has some attractive acoustical properties. First, they have an engineered volume of space that is optimized for all of the components in that particular model of speaker. Secondly, the back box adds mass, which allows more of the energy of the speaker to be directed into the acoustical wave rather than that energy being diluted into the structure and changing the sound. Typically, at a retail price of approximately $400 per room, a back box will double the audio performance in the room. Musgrave says most manufacturers have them available, and your installer should know what that are.

5. Time Is On Your Side—Bring the audio experts in early in the framing process. Do not treat the entertainment network as an afterthought. By getting involved early, the integrator will have more options for designing around architectural features. AVE uses SpeakerCraft brand speakers for most of the homes it installs. And Musgrave stresses that builders should carefully consider the subcontractor and the equipment they will use. For example, different speaker products may require different framing, and the type, direction placed and location of the framing can add or detract from the speaker performance, as well as affect vibrating or resonating when the speakers are playing.

Different considerations such as volume and frequency can also affect this. When the speakers are playing at certain volume levels, or at some of the lower frequencies, the energy expended can transfer from the baffle plate of the speaker to the substructure. This causes the substructure to resonate and sometimes even rattle. The baffle plate is the surface of the speaker assembly that holds the speaker diaphragms or cones in place.

The more rigid your speaker framing is, the better the speaker performance will be. Simply explained, the structure is not absorbing as much energy, but is a stable platform for more accurate acoustics transfer into the speakers themselves. This is accomplished by making sure all the surfaces are cut and assembled to fit together tightly.

Remember that, when integrating entertainment into new homes, the sub-structure and placement will affect the performance just as much as the equipment does.

Frank White heads Custom Metrics, which does consulting for manufacturers in the integration market. He can be contacted at frank@custommetrics.com.