Nov. 18, 2022 - Until recently, designers creating meeting rooms had two considerations when choosing the suitable microphones for the job: What mic delivered the best audio for the space, and did it fit the overall aesthetic?
Now there's another factor:
Which mic will work best with a camera tracking solution that targets a given speaker in a meeting space?
Take Crestron's Automate™ VX solution, for example; it's a speaker tracking system for larger rooms such as boardrooms, classrooms, and training spaces. "These solutions can intelligently switch and aim cameras at the active talker in the room by interpreting data from the microphones used in the room together with a room diagram to automatically locate the active talker – or the region where the active talker is," explains Rony Sebok, Crestron's director of intelligent video.
Speaker tracking technology that can seamlessly "cut" from person to person in a presentation or conversation is superior to traditional "fixed camera shot" setups. These systems mimic the camera switching you'd find in a television production without the need for anyone to operate the cameras or their accompanying switches. But picking the right mic for the right situation can further improve the end result — dramatically.
The Five Types of Microphones
There are five fundamental types of microphones, and each has its advantages (and typical use cases):
Tabletop Microphones
"Gooseneck mics are often used on podiums and for panelists," explains Sebok. "They give excellent audio for a single person because the mic is close to the person and therefore will pick up speech well."
That means, of course, they're perfect for camera-tracking systems since the speaker's audio is prominent in the mic pattern — so long as they are placed in a fixed or known location. "The Automate VX system uses a DSP to determine which gooseneck mic someone is talking into and then uses a room diagram to determine where that mic is and aims a camera there," says Sebok.
"Other tabletop mics can be used in a similar way, framing the person speaking in a 'single-shot' manner," she adds. "For example, button mics are discrete and will still give a camera tracking system good information about which person is speaking."
"Another option is a microphone such as the Shure® MXA310, which can best be described as an 'intelligent table array' microphone," adds Cara Shannon, a Crestron senior manager of product marketing. These "hockey puck" style units have multiple internal mic elements which can be optimized for a defined coverage area. Each element can be used to provide an additional position in the room for camera tracking.
Ceiling Tile Microphones
Ceiling tile mics are gaining in popularity since, as the name implies, they're highly unobtrusive, taking up zero table space — but offer a fairly wide coverage area for larger rooms. When these mics are outfitted with beamforming technology, they can effectively cover a 25 by 25-foot space while "reporting" where a beam is aimed to pick up the speaker. They're also an excellent option when a room doesn't have fixed furniture and can easily accommodate different configurations.
"The Automate VX system can take advantage of this beam direction together with a room diagram to determine which person in the room is speaking and aim the camera at them," says Sebok. "One, two, or three-person shots are possible with beam-forming ceiling mics." The resulting shots from the Automate VX system are "tighter" than competing solutions, which often only target a zone and not individual speakers.
Lavalier Microphones
Lavalier mics are also single-person mics, often used for a lecturer who might move around. Sebok explains, "The 1 Beyond AutoTracker™ camera has face detection and motion-tracking, which makes it an excellent stand-alone solution for a presenter space." When combined into an Automate VX system, the connected audio DSP identifies the lavalier mic as the active talker; it can automatically select the AutoTracker camera, further enhancing the experience.
"This combination of audio location and face/motion tracking is very powerful," she adds.
Discussion Systems
"Discussion systems are most often used in large assembly halls, which can have as many as 100 to 250 mics in a room," says Sebok. "They often have built-in speakers so that people far away from one another can still be heard, and they also have additional features to enable voting or to identify people by seating using an ID card."
Available in wired or wireless configurations, these solutions include a control system that can report which mic (or mics) are active at a given moment.
"Each individual mic generally has two operating modes, push-to-talk and voice-activated," says Sebok. "With push-to-talk mics, the mic becomes active when someone pushes the button, even if they aren't speaking. The camera tracking solution will aim the camera based on the button's trigger. This works well for organized meetings but not so well for ad-hoc discussions." As a result, voice-activated solutions are preferred for camera tracking systems.
Pendant Microphones
Pendant mics — mics that hang from a ceiling and provide broad coverage — are popular but problematic for camera-tracking systems. "Since their coverage area is often so large, the system has difficulty tracking the person speaking," Sebok explains.
"And, if auto-gain is used as part of an audio system, it's even more difficult to differentiate which mic a person is closest to," she adds.
"Ultimately, pendant mics aren't the best selection," says Sebok. "There are lots of great choices from the other types to best implement with an intelligent video system while still meeting the needs of the room acoustically and architecturally. From there, it's fairly simple for an integrator who knows their stuff to find the right fit for a room, acoustically and architecturally."
"Of course, we're always available to provide more specific guidance and design assistance to ensure the best outcome."