4604 Roseville Road, Suite 100, North Highlands, CA 95660

Insors – UNR Room 203

Acoustical Criteria:

We have found in our experience that a properly treated room is necessary for superior performance of audio conferencing systems. The three main factors that influence an audio conference system are:

1. Reverberation - The tonal quality, spatial distribution, and decay characteristics of the reflected sound energy.

2. Ambient Noise Level - The overall background noise produced by internal and external sources.

3. Sound Isolation - How well the room is insulated from noise originating from outside the room.

All of these factors, when not designed adequately, lower the intelligibility of the speech and creates a “bottom of the barrel” sound at the other end of the call.

The following is the critical criteria for a “reasonably” treated room.

The room shall measure a rating of -16db @ 60ms or have a RT60 of < .5 seconds. The exact achievement of this goal is only accomplished by hiring a qualified acoustical consultant. Typically we see rooms with approximately 50 - 60% of the room surfaces covered with a 1” fabric covered fiberglass wall board and special ceiling tiles with a NRC rating of .85 or better. A minimum treatment would consist with the inside sofit of the ceiling and at least two of the four walls. The intent is to acousticaly dampen hard surface areas that are made of glass, marble, steel, concrete and brick that are highly refelective surfaces.

The room ambient sound level should not exceed a rating of NC30. This is achieved through good isolation from outside noise sources as well as a good HVAC and lighting design and installation.

The sound isolation from outside sources, mechanical vibrations, and should exceed a rating of 55db. This is achieved through well balanced HVAC, solid wall, ceiling, and door construction.

Lighting Criteria:

Functional requirements dictate a specialized three-level lighting system for video conference rooms. These recommendations consist of the following:

4. Key Lighting - Ceiling fixtures with a directional lens to evenly illuminate the front of the participants. The light level should be 70-100 foot-candles with fixtures connected to electronic ballast for dimming. The lamp type should be 3500K fluorescent.

5. Back Lighting - Ceiling fixtures with a directional lens to illuminate the top and back of participants. Together, with the key lighting, this visually separates the participants from the background. This light level should be 70-100 foot-candles with the fixtures connected to electronic ballast for dimming. Also, the lamp type should be 3500K fluorescent.

6. Background Lighting - Wall-washer fixtures and downlights will provide a reduced lighting level at the sides, rear walls, and over the projection screens. The wall-washers need to evenly illuminate walls with a variation ratio of no more than 2:1 between the top and bottom. Also, the light level of the wall-washers need to be 2/3 the light level of the key and back lighting with the downlights over the video conferencing enviroment providing no more than 20 foot-candles on the projection screens (less than 10 footcandles is desirable). The goal is to keep the light on the participants and off the projection screens. All the wall-washers and downlights need to be connected to electronic ballast for dimming. Again, the lamp type should be 3500K fluorescent.

7. Lighting Control Interface - All lighting systems will need to be interfaced to the A/V system via an RS232 control interface. This exists between the lighting controls and the A/V system. This will be supplied and installed as part of the lighting system by others.