A successful experience depends on many factors.

Maximizing your investment in a videoconferencing facility goes far beyond buying the equipment and finding a good installation company to install it for you. You must consider acoustics, lighting, color schemes, furniture, and even the size and general footprint of your room.

Since the main source of audio input in a videoconference comes from microphones, it’s a good idea to strive for the best acoustical environment possible for the mics to operate in. You should always try to minimize the background noise in your videoconference room. This is usually measured in a metric called Noise Criteria (NC), which is a standard that was set forth in 1957 to measure steady state background noise.

For the purposes of a videoconference room, you will want to achieve NC30 or better. In practical terms, this means don’t choose a room for videoconferencing if it is located below a large building-related mechanical system such as a Variable Air Volume (VAV) box. In addition to background noise, you’ll want to make sure that at least one parallel pair of wall surfaces is treated with at least 2-inch thick sound absorbing panels. This will knock down the room’s reverberation time.

If you can, invest in an integrated door system with a Sound Transmission Class (STC) of at least 50. An STC rating is a metric relating to a material’s or an assembly’s ability to prevent sound from passing through it. Only an integrated door system ensures that it’s paired with the proper size door frame and hinging system to minimize sound transmission.

ROOM LIGHTING TIPS
Since the other source of input in a videoconference system is video, it’s critical to complement the quality of your video with good lighting. First, any light fixtures that are located in front of or near your videoconference room’s main display(s) should always be on a separate switchable circuit to avoid washing out any projected images or causing screen glares on flat panel displays. Next, all of the light fixtures used in a videoconference room should be recessed to provide a uniform field of light so that your camera’s iris does not make constant adjustments.

If possible, lighting should strike conference participant faces at 45 degrees. This is referred to as “key light.” Surfaces behind videoconference participants should be lit to separate the foreground from the background. This significantly improves video quality. The ratio of background to foreground light should range from 1:1 to 3:1. Recommended lighting levels are 750 lux (horizontal) on the table with 500 lux (vertical) on participant faces. It’s also vital that the lighting is even with no hot spots. Fluorescent lighting is usually more practical than tungsten or halogen fixtures.

Remember that the three walls that make up the videoconference background require very even lighting that starts at the ceiling line. A popular choice for meeting rooms is to use a line of single fittings, but this always provides a scalloped effect in the background, which looks bad at the other end of a videoconference call. If possible, all lighting should be a uniform color temperature. Mixing fluorescent with tungsten or halogen fixtures should be avoided. If the room has windows to the outside world, make sure there are blackout shades. Finally, if a dimming system is provided as part of the meeting room, it should be provided with an RS-232 type interface so it can talk to any AV control devices that may be a part of the system.

You should also give thought to general room finish colors. It’s a good idea to make sure that the wall surfaces avoids reflective finishes and be of a darker color scheme, since it provides a better contrast ratio between participants and background imagery.

TABLES AND ROOM
With regard to videoconference furniture, I tend to avoid the popular “V”-shaped tables of videoconference yesteryear since modern cameras have a wide range of pan, tilt, zoom, and overall controllability. Plus, those “V”-shaped tables are just not good for much else, and, in many videoconference rooms, actual videoconferences probably only take place 25 percent of the time. So it’s a good idea to just use a normal table for the other 75 percent of users.

But there are some things to consider about the table you use. First, the table should not have a reflective finish. It could cause glare. Second, if you can, select a darker finish, which will improve the contrast between furniture and people. Third, if you can provide a fixed table, do it. This will make it easier to run cables, power for laptops, and data connections to your users. If you are lucky enough to have a room that facilitates a fixed furniture arrangement, make sure your conference table has big pedestals to accommodate conduits. The pedestals should also have large access hatches on them so wiring can be properly terminated, dressed, and managed.

The last general criterion to consider is simply the size and general footprint of your videoconference room. I prefer smaller videoconference rooms, as they give users a more intimate meeting environment with their faraway friends. If you have a 26-person videoconference room, things could get out of hand with too many people talking, participants being too small in the field of view, or having to constantly pan, tilt, or zoom the camera.

I’ve been asked to fix a lot of problems in videoconference rooms over the years, and these problems are cheap to avoid upfront, but costly to fix after a room is deployed.

Joey D’Angelo is a principal consultant with Charles M. Salter Associates in San Francisco, CA, and specializes in AV/telecommunication systems. He can be reached at joseph.dangelo@ cmsalter.com.