Microphones for conferences and readings, two scenarios will show you the possibilities.

• Scenario 2: Conference, plenum, in short, a seated event with several speaking participants

  • Feedbacks: the most common cause is crosstalk from speakers to the microphone

  • Speakers for conference rooms?

This scenario is easiest, because there is only one primary microphone and one task: the presenter's voice must be heard by the audience. For this, we have to distinguish two basic examples of PA applications:

Is the presenter moving about?

Does the presenter move about, so is it more like an animated presentation on a stage? Is there a big blackboard, a whiteboard, a projector and does the lecturer therefore walk back and forth in the room? Does the presenter have to operate a laptop or even handle an experimental set-up? Then there are several options:

• A pocket transmitter with clip-on microphone or lavalier microphone. Here it is important that the cable has as little slack as possible, otherwise interferences can easily occur. The safest solution would be to fasten the cable to the body. However, this type of microphone is also susceptible to feedbacks, especially those with an omnidirectional polar pattern.
• A pocket transmitter with headband microphone or earband microphone. Here even a very active presentation style will not lead to interferences. Mind you, these microphones are a matter of taste. We have made the experience that not everyone likes wearing a microphone on their head.

Is the presenter stationary, just sitting in one place?

In this case, the easiest solution would be a directional desktop microphone. Next, we have to determine which PA scenario we are dealing with.

1. Is a presenter sitting down talking to a passive audience? Then a desktop microphone connected to the PA technology of the room would be sufficient. We recommend practical gooseneck microphones for this, for these can be aimed directly at the presenter regardless of seating position and size.

2. Is a presenter speaking to an audience, that can sporadically ask questions? In that case, the presenter should have a desktop microphone, and, in addition, a helper or moderator should have a wireless microphone to pass on to the audience.

3. Are several regular questions from the audience to be expected? Then it is rather scenario 2.

For more flexibility in setting up the technology, there are also wireless desktop microphones. Without cables, these microphone stations can be flexibly adapted to the room layout.

For regular lectures and presentations, a lectern is worth it

A lectern solves many problems at one go: a PA amplifier and a 2-way speaker system are integrated and connections for additional speakers (NEUTRIK SPEAKON) and microphones (XLR) are easily accessible. Besides, everyone who has already used a lectern knows that it has an effect. When standing upright, we talk more confidently, the arms can rest on the lectern and notes disappear behind a low screen. And let's face it, it simply looks more professional.

Here you often have 'chairpersons' in the truest sense of the word: a small group of people sitting in front of the others at the top of the room exchanging views with the larger group. For these chairpersons, especially wireless systems provide useful features that allow for an active presentation. The host, presenter or moderator can:

• activate and deactivate microphone stations of participants manually

• control individual speaker groups manually from a zone paging microphone station,

• even prioritise individual microphone stations in the plenum,

• set the speaking time for individual or even all speakers

Here we have three main options for realising a conference:

1. A wired microphone at each (speaker's) table is not expensive anymore nowadays. Good desktop microphones are available for less than EUR 100.

2. Boundary microphones, that are sensibly distributed on the tables, are always a good choice if you are dealing with sound-reflecting surfaces. With reflecting surfaces in the immediate vicinity, boundary microphones work particularly well. Some can be switched between cardioid and omnidirectional polar pattern. 

   • You need a cardioid polar pattern if the participants have their own microphones at their individual places.

   • You need an omnidirectional polar pattern for a group table where people speak from several directions into one microphone.

3. Microphones on the ceiling. These so-called installation microphones are specially developed for ceiling suspension and are directed towards the speakers' positions.

Feedbacks in PA scenarios such as conference rooms, plenary halls or seminar rooms are mainly caused by the variety of microphones. Three general rules help preventing that: 

1. You should plan the PA system in a way that no speakers, not even ceiling speakers, will radiate sound into the desktop microphones at the individual places.

2. You should use microphones with cardioid and supercardioid polar patterns.

3. The sound sources, in this case the persons speaking, should be positioned close to the microphones.

1. Microphone types and their technological fundamentals 

When planning audio technology for conference rooms, installers and planners are faced with selecting the suitable microphone type. Condenser microphones offer excellent sound quality due to their sensitivity and wide frequency response. However, they are also susceptible to ambient noise. Dynamic microphones, on the other hand, are more robust and less susceptible to background noise, making them ideal for loud environments. Array microphones, which combine multiple directional microphones, can be aimed at the speaker in a targeted manner, making them particularly useful in conference situations where precise speech capture is required.

2. Setting up and optimising the microphone positioning  

The correct positioning of microphones is crucial when it comes to achieving the best possible sound quality. Microphones should be positioned close enough to the speakers to ensure clear voice reproduction, but in such a way as to minimise interference from other sources of noise. Taking the polar pattern of each microphone type into account can help eliminate unwanted ambient noise. In addition, the room acoustics must be taken into account. Hard surfaces reflect sound and can generate echo effects that need to be mitigated by acoustic dampening materials such as carpets or panels.
 

3. Noise suppression technologies  

Modern conference microphones use advanced noise suppression technologies to filter out unwanted background noise. These technologies use algorithms that can distinguish between speech and background noise in order to actively suppress the latter. This not only improves sound quality but also increases speech intelligibility, which is particularly advantageous in acoustically challenging environments.

4. Integration into existing audio/video systems

The seamless integration of microphones into existing AV systems requires technical know-how regarding compatibility and connection options. Check that the microphones are compatible with your existing mixers and digital interfaces and whether they may have special requirements such as phantom power. Professional coordination of the microphones with the AV system ensures high sound quality and prevents latency issues.
 

5. Future trends and innovations in microphone technology  

The conference microphone market is continuously evolving, with a clear trend towards smarter solutions. Future innovations may include automated calibration systems, improved digital signal processing and AI-based speech recognition technologies that enhance conference efficiency and improve user-friendliness.

6. Legal aspects and data protection  

When using microphone technologies, data protection aspects also need to be taken into account. Recording conversations in conferences can raise data protection issues, particularly if people are recorded without their explicit consent. It is therefore vital to provide explanations and obtain declarations of consent in order to avoid any legal complications.

Speakers for conference rooms?

There is a general rule that basically applies to all rooms with PA speakers: more sensibly distributed quieter speakers are preferable to fewer louder speakers. Ultimately, it depends on whether there are already sound sources distributed in the hall that you can control via mixing amplifier or whether the microphone stations themselves have to serve as speakers.

_{^{Image source Headergrafik: Ingo Bartussek – stock.adobe.com}}