Sound Systems for Your Large Meeting Rooms

A sound system plays a significant role in the school gym or auditorium. But what about the other large rooms in the school such as the lunch room or the lecture halls? These facilities are often host to community meetings or political meetings. Of course, the same rooms are also used by the school system itself for staff meetings or student club events. Whatever the situation, the need for a well functioning sound system is important.

Whether you need to update your present system or install a new system, there are several features that should be considered. First, how many microphone inputs do you need? Should it be able to play music? Where is the best place to locate the mixer? What type of speaker system should I use? Let’s look at these questions and discuss some potential solutions.

How Many Inputs are Needed?

A typical mixer used in a large meeting room would have four to eight inputs. The number of inputs will often determine how many microphone inputs are available. For instance, a six channel mixer may be configured so one input is connected to the school paging system (Fig. 1). Another line input could be used for a cassette deck for music playback. The remaining four inputs are dedicated for microphone inputs. Figure 1 shows input 4 is reserved for a wireless microphone.

Don’t assume that just because the mixer has only two or three inputs remaining for microphones that this limits the possible locations for microphone jacks. Look at Figure 1 again. You will notice each microphone input on the mixer has more than one jack location. This provides greater flexibility in microphone positions to meet a variety of uses. The multiple jacks are based on the assumption that no more than one microphone per mixer input will be used. However, if two microphones are used on the same input, the only harm done will be a reduction in sound quality.

If you do need more microphone inputs than the mixer has, other solutions are available. For example, a separate portable mixer could be used. If the portable mixer has a microphone level output, which many have, it could be plugged directly into a microphone jack. The portable mixer line level output could also be connected to a “direct box.” The microphone level output of the direct box is then connected to a microphone jack of the room’s sound system.

Figure 1

Where Should the Mixer Be Located?

The location of the mixer/amplifier is important. It probably needs to be in a lockable cabinet either in the room itself or in a more secure nearby storage room. If the mixer is located in the room itself, try to position it so the operator has good sight lines and can also hear the sound system. You will also want to limit access to the system’s controls so curious fingers don’t cause big headaches.

If the mixer is located in a remote storage area, a remote volume control is very handy for setting the proper volume. This remote control could vary from an overall master volume control to individual controls for each input. It’s also possible to install controls that are only adjustable with a key-activated switch. Controlling the volume from multiple strategically located panels is another option.

If the mixer is located in a storage room, make sure to locate it close to the door as it is too easy for access to get hampered by tables and chairs, etc. Another good idea is to install a loudspeaker monitor in the equipment room. This loudspeaker should be set at the same volume level as the main loudspeakers, so adjustments at the mixer will be appropriate for the meeting room.

What Type of Loudspeaker System Should Be Used?

This is a difficult question to answer without knowing what the room is like and how it is used. The loudspeaker should cover the entire listening area with sound that has consistent quality and is the same volume. This is far easier said than done. Depending on the ceiling height and the shape of the room, there are numerous alternatives for loudspeaker type and location. However, most meeting rooms have a relatively low ceiling in relationship to the area of the room. Because of this, a distributed system of loudspeakers mounted in the ceiling is the most common design. This al-lows the mic-rophone to be located almost anywhere in the room.

Figure 2

It is often advantageous to have the loudspeaker(s) that are directly over the microphone turned off. This will help the system operator to achieve enough volume before that dreaded feedback “howl” occurs. This loudspeaker muting system is shown in Figure 2. The local loudspeaker is automatically muted when the microphone cable is plugged into the corresponding microphone jack.

Can the Large Meeting Room Be Split into Smaller Rooms?

Perhaps you have several small rooms which can be combined to form a large room. You will probably need a zoning feature on the sound system. With this, you can turn off the sound to areas which have no need of the sound system. The system in Figure 2 is an example of a simple two zone system with a remote master volume for each zone. You may need a separate system for each small room. The separate systems can then be bridged when the rooms are combined.

Optional Meeting Room System Equipment

There are many other options which can be added to the meeting room sound system which help provide more consistent, high quality sound. One example is the automatic microphone mixer. This mixer automatically turns on the microphone when somebody speaks into it. This helps prevent feedback by keeping unneeded microphones turned off. Another good option is the leveler. The leveler is like an automatic sound system operator; it will adjust the volume up or down to achieve a more consistent sound level.

Why Does It Have To Be So Complicated?

It doesn’t. The sound system need only be as complicated as necessary to meet the needs of the meeting room. Furthermore, a COMPREHENSIVE sound system isn’t necessarily complicated to operate!

by Ron Huisinga © 1996 Internet Sound Institute (www.soundinstitute.com). This article is for personal use only. Any commercial reproduction is not permitted without permission. To obtain permission, contact ISI at hopi@soundinstitute.com

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