One size does not fit all in corporate, civic and institutional applications where speech intelligibility in meetings and conferences is so critical. As IT staff increasingly move into AV roles, many are forced to think analog instead of digital. This role shift includes responsibility for making good microphone choices. This article is for anyone who runs sound in the world of meetings and conferences, whether your background is in the IT or the AV world.
Factors To Consider in Mic Selection
The optimal audio solution for a meeting depends on a range of factors, including:
- Room size
- Number of people involved
- Number of presenters
- Presentation style
What does “presentation style” mean?
- One-to-many: one person addressing an audience (example: a lecture)
- Many-to-many: all attendees speaking at will (example: an open forum)
- Hybrid: special cases of many-to-many communication with restricted or prioritized microphone access (examples: city councils, courtrooms, boardrooms, and panel discussions with an audience)
Additionally, you must consider whether or not a sound reinforcement system is involved.
Start With Your Space
Below is our quick study guide to microphone choices for seven common meeting and conference environments. Find the space that’s closest to yours, then check out the recommendations.
#1 Huddle Room
Description: This is a small room that accommodates 4–8 people, usually around a single table.
Sound reinforcement: In general, there is no need for sound reinforcement in basic meeting spaces; however, many huddle rooms incorporate audio or video teleconferencing, which may be portable or permanent.
Microphones: No PA here, so this is a perfect situation for an area miking approach. If the system doesn’t have its own dedicated microphones, try placing a couple of wired or wireless boundary microphones on the table. One or two small condenser microphones hanging a few feet above the table can be a feasible alternative.
#2 Meeting Room
Description: A larger version of a huddle room, the meeting room may accommodate 6–30 people at one or more large tables, often seated “in the round” so that participants can see one another.
Sound reinforcement: If the room has well-controlled acoustics (not too reverberant), sound reinforcement may not be required; however, both recording and teleconferencing are common in meeting rooms, which means that microphones will be required.
Microphones: Whenever four or more microphones are used, we recommend turning off unused microphones. The easiest way is to use microphones with integral On/Off switches and rely on the presenters to operate their own microphones. Another strong possibility is a dedicated discussion system or automatic mixer, which removes that burden from the participants, improving focus on the meeting itself. A discussion system also has the advantage of integrating a small sound system into each microphone station, virtually eliminating any chance of feedback while making it easier for people at opposite ends of a long table to hear each other.
Most people gravitate to having one tabletop microphone per participant, but one microphone for every two people is often sufficient. Gooseneck microphones on the table are the preferred option in meeting rooms because they can’t be inadvertently covered by papers, although boundary microphones can also be used. If the tables are movable, wireless tabletop microphones can provide flexibility and speed of setup. A discussion leader is a good candidate for a headworn or lavalier wireless microphone.
#3 Training Room/Classroom
Description: This is a classic one-to-many communication scenario, with up to 30 students at chairs or tables facing the instructor/lecturer.
Sound reinforcement: The larger and more reverberant the room, the greater the need for a sound reinforcement system at the front, facing the learners. Smaller rooms that do not require a sound system may still need miking to feed streaming, videoconferencing, and/or recording of the presentation. Maximizing intelligibility is critical in any learning environment.
Microphones: The lecturer may work from a podium, but is more likely to move about during the presentation to use a blackboard, whiteboard, or other presentation tools. To accommodate hands-free voice pickup, a headworn or lavalier wireless microphone is the preferred solution.
Student questions can be fed into a distance learning link in a number of ways. A dedicated microphone can be placed at a specific table or on a stand for this purpose, or a handheld wireless can be passed around as needed. Overhead miking of the seating area should only be considered when no sound reinforcement system is involved, and only in rooms with good acoustics. If the class experience is intended to be highly interactive, consider a system of desktop microphones with an automatic mixer or discussion system.
#4 Lecture Hall
Description: A lecture hall is a larger version of a classroom, with an audience of 50 or more. Larger facilities seat over 200 people and often have tiered, theater-style seating.
Sound reinforcement: A lecture situation does not accommodate miking for all audience members, and a PA system designed for high intelligibility is definitely required. Fortunately, lecture halls are relatively stable in their usage, allowing dedicated system design.
Microphones: As in the classroom, a lecturer is best served by using a wireless lavalier or headworn microphone to keep both hands free, or a gooseneck or stand-mounted microphone at a podium. If it is unlikely that the instructor will be actively using visual aids, a handheld wireless is also an excellent option.
Student input is more challenging in lecture halls, since both students and the instructor may have difficulty hearing questions. This is an ideal situation for one or two dedicated microphone stations in the aisles, placed in positions where the threat of feedback is minimal. Alternately, a handheld wireless microphone can be passed around. Despite being on the “wrong side” of the PA system, a handheld should be close enough to the talker to be relatively safe from feedback.
For the instructor, consider providing a dedicated monitor speaker specifically for questions from the audience in the room and in distant locations if needed. As previously discussed, overhead microphones can be problematic in picking up audience questions in a sound reinforcement situation unless the output is safely routed to avoid feedback issues.
Description: Videoconferencing systems allow two or more distant locations to communicate with simultaneous audio and video transmissions over telephone lines or broadband network connections so that multiple groups can interact in real time. They are useful for both meetings and education.
Sound reinforcement: There are two types of systems: dedicated and desktop. They can be based on either traditional telephony or an enterprise VoIP system.
Microphones: The biggest audio problems in videoconferencing tend to be related to microphone placement. Distant mics produce a hollow, indistinct sound and increase the potential for echo problems. Placing microphones within arm’s reach of all participants is a good guideline for improving sound quality and has the added benefit of improving the performance of the system’s acoustic echo cancellation (AEC).
In general, treat a teleconference like any other live sound reinforcement situation, remembering to minimize the visual footprint of any microphones that may be seen in the presentation or meeting.
Description: A boardroom differs from a standard meeting room in that it usually incorporates turnkey control systems so that participants can concentrate on the proceedings instead of the AV equipment. Typically, a control system, such as those made by AMX®, Crestron®, and Extron®, is programmed by the room designer to enable any needed equipment through a single touchscreen remote control.
Sound reinforcement is usually limited to videoconferencing systems and video playback systems.
Microphones: Microphones are common in boardrooms, both for teleconferencing and as a means of recording the proceedings for archival purposes. Automatic microphone systems are popular in boardrooms since they capture the proceedings without having a system operator in the room.
In a boardroom, aesthetics are always a major consideration. Permanent microphones that require drilling through expensive conference tables to run cables pose a challenge. That’s why tabletop wireless microphones are becoming very popular. They can be removed quickly when not in use, and many models offer audio encryption for security purposes.
#7 City Council/Courtroom/Large Meeting Facilities
Description: The bigger the meeting facility, the greater the need for advanced systems. With a chairman presiding over a large group, plus an audience gallery, a comprehensive sound system with advanced features is required. International conferences are even more demanding due to the need for interpretation capabilities.
Microphones: Automatic microphone systems are a starting point. The ability to minimize the number of open microphones helps maintain intelligibility and ensures that all talkers are heard. In addition, many automatic microphone systems allow the chairperson’s microphone to take priority over others.
Many installations can benefit even further by using a discussion system or conference system. These systems address one of the biggest problems of sound reinforcement for meetings by incorporating a small loudspeaker into the base of a tabletop gooseneck.
Of course, every space is different, and some will fall outside these guidelines. Some have very specialized user requirements that are reflected in the sound systems they use.