The Invisible Audiovisual System

One issue that we face with our projects is making technology transparent within the space it occupies. For many projects, the end users and owners want to see the audio and/or visual systems they spent their money on. They want to showcase their system and make it a visible focal point of the facility. But other clients view the system and its individual components differently; the technology is there to serve a purpose, not create a distraction or act as a decoration. Their conference room can be filled with any of the latest technologies, just as long as the equipment blends into the surroundings. Whether you want to showcase the presentation system or camouflage it, some common issues need to be addressed: wall mounted controls, projectors and screens, loudspeakers, microphones, and user-accessible equipment.

Combining Controls

Often when you walk into a room you will see an array of wall-mounted devices. How many times have you seen an on/off light switch, dimmer, exhaust fan switch, projection screen control, and remote volume control on five different wall plates spread out over three feet of the wall area? One wall plate is silver, one is an ivory toggle, one is a gray decora, and the others are some shade of color that almost matches the wall paint.

These multiple functions should have been combined into a single faceplate-which hold from one to four switches- with labels clearly identifying each button. These plates come in a variety of colors and finishes. Grouping and naming the switches is a simple idea that will save frustration (and embarrassment) when you try to dim the lights and instead change the temperature in the room or kill the power to the projector. If the system is very complex, the push buttons and switches can be replaced with a small LCD touch screen control. This detail is just one of the responsibilities of the audiovisual design consultant.

Concealing Components

Clients who want to view large images in the conference room need to make a choice between using a projector or a large monitor. The number of people that need to see the image, and the type of image (high resolution for computer graphics or lower resolution for general video viewing) helps to determine the type of display device used. Projection screens obviously come in larger sizes than monitors and are favorable for reaching bigger audiences. However, both projected and direct view displays have their own requirements for integrating a system within the room.

Ceiling-mounted projectors are bulky and can be a visual distraction from a room’s design. While their size makes it difficult to hide the entire unit, the projector could be housed in a soffit or lowered from the ceiling by a mechanical lift. Large monitors that we typically find in conference rooms can weigh 250-350 pounds and could be up to 40 inches wide and 30 inches deep. Monitors this size can either set on the edge of a large credenza, or be integrated into the casework or furniture design. Smaller models can be placed on a platform that raises up from inside a credenza. However, the weights and dimensions for these monitors are larger than one would typically expect.

Loudspeakers are another common component whose appearance can be easily minimized. Next time you are in a large office building or hotel lobby, look up at the ceiling. What do you see? A majority of the time, you will probably see two or three different types of loudspeaker grills within close proximity of each other. One will be for background music, the other might be for a fire alarm system, while the third is for the paging system. These loudspeakers serve three separate functions and were probably installed by three different contractors. Again, this is something the project’s audiovisual design consultant would have avoided by coordinating all these functions into one or two enclosures. If building codes prevent this, the grills could be coordinated so they all have the same general appearance.

What about microphones? In the Summer 1993 issue of this newsletter we talked at length about how microphones really need to be on the conference table (as opposed to ceiling-mounted). The style and type of microphone selected should be dictated by its function and the number of people who will use it at any given time. A copy of the article can be found on our web site under the newsletter/article link, or give us a call if you need a copy faxed.

Equipment Access

There are two different sets of equipment for audiovisual systems. The first set is static equipment; power amplifiers, equalizers, switches, and other components that usually do not need adjusting after they have been set up. The second is comprised of all the audio and video sources: computer to video interfaces, VCRs, laserdisc or DVD players, cassettes, CDs, and slides. Each of these items must be accessible by all present including those in wheelchairs. In many cases, source equipment should be separated from the rest of the equipment, or at least located in the lowest portion of the equipment rack.

An Increasing Need

So just how important is system/facility integration? With everyone going ‘on-line’ with greater frequency, many meetings are now relying on high technology presentations. In the corporate, training, education or boardroom setting, computer-based presentations are becoming the standard. Almost every student graduating with a technical degree-whether in business, engineering, or science-uses a computer. They are familiar with electronic presentations; their instructors have already been using this technology. As more and more educational facilities incorporate campus-wide networks and large screen display systems in their classrooms, students will assume that this is the norm for business environments. Firms almost always ask for large screen monitor displays for their conference and training rooms once they see their peers and competitors using similar systems.


What is a sone? A sone is another one of the wonderful terms the acoustical industry has generated to confuse all of us. Sones are most commonly found in the rating of small fans; even more so for residential bathroom fans. Personally, we would not select a fan that is any louder than 2-1/2 sones for our home, which is a level that is noticeable but not objectionable to most people. To give you an idea about how loud a sone is, 6 sones is the level that we typically speak at when seated around a conference table. Keep in mind that noise is a subjective thing which varies depending on a person’s tolerance to such. One person’s Metallica is another person’s Mozart. The following table relates sones to A-weighted decibels.

dBA 40 50 55 60 65 70 75 80 85 90
Sones 1 2 3 4 6 8 11 16 22 32

As you can see, sounds heard at 80dB are not merely twice as loud as 40 dB, but are actually 16 times louder!