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Corporate AV Special: The rise and rise of the mic

They have always been there, but usually for very specialised purposes. Now microphones seem to be everywhere. We look at how this happened and the different types of microphone available for AV work –as part of our Corporate AV Special in the latest edition of Installation

Microphones have always been important in corporate AV. The change in recent years – and particularly over the period covered by the pandemic – is that people seem to have at last realised just how important they are. As business relied increasingly on video call technology for meetings and conferences, it became apparent how adding an external microphone – even a $20 gaming condenser model – could improve sound quality. And the meeting itself.

When people eventually returned to offices, there was more appreciation of how microphones could not only help in the amplification of presentations and meetings but also improve speech intelligibility, which in turn improved the understanding, even the enjoyment of the occasion. There were also practical considerations; the need for social distancing within a room meant participants were further apart, which again called for some form of technical assistance in ensuring everyone could hear what was being said.

“There has definitely been an increase in microphone requirements and usage for corporate AV and that’s partly because – happily – there’s a general awareness in the industry for the need for really good audio alongside other AV elements,” comments Tom Griffiths, application, training and support manager at Audio-Technica UK. “That’s not always been the case but people now expect clarity and intelligibility wherever they’re meeting or gathering, whether in person or virtually.”

René Mørch, director of product management at DPA Microphones, agrees there has “definitely” been a rise in both the use of mics and awareness of their importance. This, he says, has “been fuelled by the pandemic”, while acknowledging that the company’s products would generally be found at the higher end of corporate, not in people’s home offices. “We’re involved in environments where there are more people needing to communicate from the same meeting room with six to eight or more participants. People are now more used to a video call and it is convenient to see what people’s reactions are and whether they are paying attention to what is being discussed. But what they are not getting tired of is not bad video quality, it’s poor audio. That’s what makes you tired.”

This is something, Mørch adds, that had been recognised for several years before Covid but the greater reliance on video conferencing has emphasised the benefits proper miking can bring. Rob Smith, senior director of systems sales at Shure, observes that mics continue to be used for many of the same purposes as they always have over the years, such as town hall presentations and training seminars, in addition to video conferencing. The different now, he says, is that the number of rooms equipped for remote meetings and the reliance on that technology for day-to-day business operations has increased dramatically.

“Today, a room with no technology is rare and the reduction in cost brought about by cloud-based unified communications [UC] systems such as Teams, Webex and Zoom has enabled the number of video conferencing enabled rooms to vastly increase,” Smith explains. “The ongoing Covid crisis and attendant need for more remote working has created a demand for improved audio quality from wherever a team member is located. This is because if the participants cannot hear and be heard, the value of decisions that emerge from a meeting will be vastly reduced.”

Inesh Patel, business development manager for business communication at Sennheiser UK, agrees that the requirement for microphones has “probably increased if anything else” because of the larger amount of online interaction in commerce today. “The big increase has been in these all-in-one, plug-and-play type solutions that have microphones built-in, maybe with a speaker as well and a camera for slightly larger applications,” he says. “As you get into bigger meeting rooms you’ve still got those all-in-one systems, maybe larger soundbars, or a codec package that might have a camera separate to it with an extendable microphone in there. Those meet the requirements for those spaces but what has always got to be remembered is the limitation of those all-in-one solutions. They are limited to the size of room they are designed for. When you get to huddle rooms for three to four people, that’s when you get to microphones that can be extended on tables.”

Problems arise, Patel says, if users misjudge the capabilities of devices for smaller situations and attempt to utilise them in bigger scenarios than they were designed for. “They soon realise that maybe the audio quality is not up to scratch and that’s when you need the expertise of an AV integrator or system designer to incorporate separate units, including a decent microphone or microphones, for that particular size room,” he comments.

The type – handheld, lavalier, gooseneck or head-worn – and polar characteristics – cardioid, hyper-cardioid, omni-directional – of a microphone are key points when considering what is needed for a specific application or installation. Which is where practical experience of what different mics can do, which might otherwise appear somewhat arcane to the more casual or non-technical user, is invaluable.

“In meeting rooms there is the question of whether you want something on the table or you want it to be declutterised,” Patel comments. “Traditionally we’ve always emphasised gtting microphones as close to the sound source as possible but with the  latest technology, especially beam-forming, you can comfortably get further away from the microphone without loss of quality. That’s really changing people’s attitudes and helping improve audio quality. But for more traditional requirements, where you might have someone behind a lectern at the front of a room, we would put mics on the lectern or the speaker might wear a lapel mic or even use a handheld. The choice of capsule makes a big impression, particularly when it comes to rejection properties of the microphone in relation to loudspeakers or floor monitors.”

The capsule is the element within the microphone body that converts sound waves into electronic impulses. This process starts with the diaphragm, which contains a membrane that vibrates as sound hits it, with the conversion itself performed by a transducer. The two main types of transducer in use for microphones are condenser, the most common form and which works on electrostatics, and dynamic or moving coil, which operate using electromagnetism.

Shure’s range of microphones for home working, the MV Series, features a digital condenser model with a cardioid pattern and three DSP modes. Cardioid microphones (so called because the polar plot is heart-shaped) have good pick-up from the front (on-axis) and sides (off-axis) but not much from the back. Hyper-cardioid offers a tighter response, with both it and cardioid varieties coming under the heading of directional microphones. Omni-directional microphones, by contrast,  are able to pick up sounds from every direction, with output being constant for all angles of incidence.

“The traditional microphone types all have a place within the corporate space,” explains Rob Smith from Shure. “The cardioid mic-on-a-stand style still provides probably the best solution for single talker applications, or indeed performers on stage. There are now far more advanced options available for multi-participant meetings and other use cases.”

Among the most recent developments in microphone technology is beam-forming. This relies on an array of microphone components, which creates a coverage pattern that can be directed and cover a large area with only a single unit rather than multiple individual microphones. Smith comments that array microphones such as this have offered corporate users more flexible options when it comes to audio. “Microphones can now be moved off the table without losing quality,” he says. “Multiple arrays can be joined together to ensure all speakers can be heard and background noise can be eliminated for the best possible meeting experience.”

A new feature for beam-forming/array mic system is voice lift, an automated process that amplifies someone’s voice in the more distant areas of a large room. As Smith observes, this has proved useful in Q&A sessions during the pandemic because it means there is no need to pass round a wireless handheld mic, as would have happened in the past.

Another type of device commonly used in the corporate world, particularly for conferencing, is the boundary microphone (also known as a pressure zone mic). This usually has capsules supported on a flat plate or housed in an enclosure, which is placed on or near a boundary surface, such as a table, wall or floor. Boundary mics can be either omni-directional or cardioid, with Audio-Technica favouring the latter pattern for its ATND971. “Where delegates might be gathered fairly closely around a conference room table, a cardioid model might be ideal for helping to isolate speakers and rejecting noise pick up from around the room,” says Tom Griffiths. “For less formal situations, such as huddle rooms, an omni-directional mic that picks up sound from everywhere and covers all contributors with a single mic might be the best choice. Although great audio quality is really important, so is providing a solution that is workable and affordable.”

Griffiths adds that another technology being used in conjunction with  microphones for corporate installation is networking. “This caters to the particular requirements of installed applications,” he says. “Our boundary mic has Dante capability, which means it can be easily added to, and control devices on, a network. Increasingly we’re finding a requirement for network audio solutions as end-users and specifiers grasp the benefits of ease-of-installation, functionality and configurability.”

DPA produces an omni-directional boundary mic, as well as gooseneck, lavalier and handheld models. While several manufacturers have opted for beam-forming technology for ceiling-mounted microphones, including Sennheiser with the TeamConnect Ceiling 2, DPA has instead offered its regular directional microphones for this purpose. René Mørch, who worked for systems integrator the Danmon Group in between his first term and what is now his second period at DPA, explains that the 4099 super-cardioid instrument mic is used in corporate installations, with an acoustic interference tube fitted in front of a 500mm capsule to give even greater directionality.

“This is the same principle we use for ceiling-based applications and also for goosenecks on lecterns and tables,” he says. “Our directional microphones on the off-axis are linear, which is unusual. I have used them in corporate situations and by placing just one mic at the top of the screen in a meeting room, pointing down at the people furthest away, you will have equal coverage over distance because the mic is equal in the off-axis due to dampening.”

There was a time when microphones were something out of the run of everyday life. Rock stars would swing them around on stage and TV reporters would grasp them while looking seriously in the camera. Today they are an important factor not only in the corporate world but people’s home life as well. And there’s no sign that’s going to change any time soon.