Audio Is The Senior Corporate Partner
For some audio visual equipment is actually the senior partner. “It depends on the context,” says Richard Knott, sales and project engineer at Shure Distribution. “For conferencing and meeting spaces audio is absolutely critical. If you’re having a video conference and you lose the audio then you can’t communicate effectively, if at all. Without video at least you can have an audio call. In presentation spaces it’s probably more balanced as you want to be able to see and hear clearly.”
Audio systems should be designed at the very beginning of a project alongside video, argues Stuart Taylor, integration project manager at Anna Valley. “Ideally both video and audio should be considered at the same time as architecture and office design, because building materials, size and shape of the room, furnishings and wall and floor finishes will all affect how the sound travels within the space. Unfortunately, this seldom happens, which explains why manufacturers are now developing technology like wireless microphones that can be retrofitted!”
“Program audio that’s tied to content on a display has to have properly placed loudspeakers, potentially impacting aesthetic and acoustic decisions for the room,” adds Joe da Silva, director of product marketing at Extron.
As a minimum, all audio systems require input devices to capture the sound, typically microphones, and output devices to make it audible, such as amplifiers and loudspeakers or acoustic panels. More likely than not, you will also need some technical hocus pocus in the middle, not just to get the input and output components to talk to one another and synchronise with the video, but also to handle remote transmission, improve the sound quality, and so on.
“The type of microphone will be influenced by how the room will be used,” says da Silva. “For example, will individual control be required per participant, as in a larger system, or will a single mic work with all participants surrounding it, as in a huddle space?”
“Microphones must capture audio from people speaking, therefore the pick-up range and polar pattern must work with the seating positions, whether it’s a ceiling or table-top microphone,” says Darren Barton-Taylor, sales director at Focus 21. “Cardioid polar patterns capture audio in front of the microphone rather than behind, which helps eliminate unwanted noise.
“A new innovation is beam forming technology, which allows the pickup nodes within a microphone to be sized and steered to particular positions within a room rather than relying on the natural pick up patterns (cardioid or omnidirectional).”
“Wireless microphones for presenters and conferencing eliminate messy cables and enable users to move more naturally,” adds Alison Charters, senior product manager at Midwich.
“Loudspeakers will range from ceiling speakers for basic background audio or a basic stereo system, up to a full voice lift system with a high density of ceiling loudspeakers in large spaces,” says Knott.
In smaller spaces a single loudspeaker usually suffices. For deeper spaces (say more than about 15 metres) an array (configuration of multiple speakers coupled together to act as a single sound source) tends to give more sound projection and better coverage. In a conference space each delegate position may also have its own mini-speaker.
says Knott.
In smaller spaces a single loudspeaker usually suffices. For deeper spaces (say more than about 15 metres) an array (configuration of multiple speakers coupled together to act as a single sound source) tends to give more sound projection and better coverage. In a conference space each delegate position may also have its own mini-speaker.
Sound pressure
The most important number in a speaker’s specification is its sound pressure level (SPL), the best indication of its potential loudness. “Speakers and amplifiers must be powerful enough to reach the required SPL within a room, which makes an appropriate system dependant on the room size,” says Barton-Taylor. “Users shouldn’t disregard low frequencies, which are achieved using sub woofers and ensure voice reinforcement is well rounded and natural.”
In all but the simplest systems, between mics and speakers sits digital signal processing (DSP) technology which helps ensure that the optimum sound reaches each loudspeaker at precisely the right time. “DSP is the heart of the system, providing routing, automixing, acoustic echo cancellation, equalisation and dynamics processing,” says da Silva. “Most DSP products today are scalable so that one unit might be used in a small room while several units networked together may be required in a larger application. Some now integrate VoIP (voice-over-IP) capabilities, too.”
“There may be USB audio interfaces in meeting rooms so people can use their laptops with room systems, or soft codecs like Skype for Business or BlueJeans,” says Knott. “There may be a need for much larger DSP equipment in a central control room, which supports a more hands-off approach and allows control via hard-wired, touch panels or wireless via iPads or tablets.”
Audio for smaller spaces
While a larger room may have a permanent video conferencing system with rack-mounted DSP equipment, this may be unnecessary in smaller rooms and huddle spaces, Charters believes.
“A new generation of versatile kit complements these multi-purpose rooms by employing the laptop or mobile’s web conferencing software, such as Skype for Business, Lifesize Cloud or Zoom, to communicate,” she says. “Then users have an interface they’re familiar with, but in a larger setting where others can join their meeting.
The Revolabs CS700 offers users a familiar format in the shape of a consumer-style soundbar with integrated 120-degree camera and beam steering microphones, which ensures easy USB connection to the laptop and good quality audio both in the huddle space and at the recipient’s end.
If you have a large number of multi-purpose rooms it’s worth considering a portable PA system, Charters adds. “Invest in a protective bag and stand and they can be stored and brought out as required. The LSP 500 from Sennheiser even enables the user to wirelessly daisy-chain systems together to cover big conferences.”
Mixing consoles
At the other end of the scale, companies with larger presentation systems may use a full mixing console, with a member of staff trained to manage the system as a whole, says Knott.
We live in a noisy world, exacerbated by the trend towards open-plan offices and impromptu meeting spaces, which means that background noise can be a real nuisance.
“To counter these challenges audio product manufacturers have made massive progress in noise cancellation and speech privacy in recent years,” says Taylor. “Now you can give a presentation using technology that constantly adapts the listening levels to ensure that your audience hears you clearly while blocking out any ambient noise, and directional speakers allow you to deliver great sound quality to a specific area only.”
“Our NoiseBlock technology can distinguish the human voice from other sounds, so it shuts off the audio from a speaker after participants have finished talking, removing unwanted background noise such as rustling papers,” says Andrew Hug, EMEA vice-president of systems engineers at Polycom.
“AEC (auto echo cancellation) is a must when using audio or video conferencing,” adds Barton-Taylor.
Don’t make the mistake of confusing high volume with high quality, cautions Taylor. “Good audio design should provide comfortable volumes to the entire audience, regardless of their situation. Loudspeaker placement will be key, while zonal processors will be required with speakers delivering the audio at different levels to different areas of the room.”
Software replaces hardware
Network connectivity can make the expansion of inputs and outputs or functional capabilities more straightforward, says da Silva. “AV networking is affecting all parts of the market. Audio-over-IP with Dante, Wi-Fi control from a smartphone, and the ability to use standard networking hardware to move signals around, are examples of relatively new capabilities that are driving entire new segments of the market as well as redefining the cost/benefit ratio for users.”
But putting audio on the network brings its own issues, cautions Knott. “Properly planned networking infrastructure is critical to making all elements work well. With more and more AV devices living on corporate networks or their own separate AV networks, end users need to be aware of all the requirements of setting up networks for AV and realtime processing and communication.”
Software solutions are increasingly replacing hardware, Knott finds. “We’re seeing more companies taking onboard platforms such as Skype For Business, Zoom and Google Hangouts, where in the past they’d have relied on hard video codec.”
As with so much AV technology intended for general business users, ease of use is a paramount concern. “The key words in current corporate AV spaces are collaboration, ease and experience,” says Simon Druce, sales director at CUK Audio. “If people can walk into a room or location and easily communicate with technology that enhances their experience they’ll be more productive and willing to participate.”
“In corporate environments AV users can vary from highly skilled technicians to complete technophobes, so technology needs to be accessible to the people that will use it,” says Taylor. “The control interface in a meeting room should be the only piece of technology that users need to interact with, providing a simple interface that controls all the technology in the room. Conversely a large auditorium may have a tech engineer to operate the system on users’ behalf, so more independent control might be required.”
“With all the new demands and technologies available it’s very important to design a system that’s ‘foolproof’ and very easy to maintain,” adds Marc Kocks, business development manager at Powersoft. “Buyers should be looking for products capable of offering remote monitoring and control featuring live impedance measurement.”
Don’t neglect the aesthetics either, Druce advises. “We’re seeing huge demand for clean table lines, so ceiling mics (in the form of beam arrays) are important, and so are high quality architecture, engineering and construction so that products can be integrated while maintaining aesthetics and user operability. Arthur Holm is a good example of a brand that pays attention to these.”
Every space can have different acoustic properties and challenges, so matching the audio to the space is vital. “The ability to tune a system for the space it’s in is a key criterion,” says Jeffrey Singer, executive director of product marketing at Crestron. “Audio gain, gating and AEC are all critical. Having a system properly tuned to compensate for delay, tonal quality to optimise speech audio, and for speakers, crossover, smooth frequency response and proper throw for the space, are important.”
While no one should install a new system on the cheap, the most expensive solution is not always the best, warns Bob Farahar, channel director at Phoenix Audio Technologies. “Much of the time the option with the highest quote requires more time and manpower, not to mention a complex installation. So go for a simple solution that doesn’t take a rocket scientist to install and that can be adjusted by any of your staff.”
Tailoring to fit
Finally, don’t be dazzled by big-name vendors, Druce advises. “Many smaller companies offer higher levels of support and, more importantly, the ability to work more directly with the user and therefore tailor an offering that truly fits rather than a generic one. I’d also suggest that a complete solution from one manufacturer may not always be the best. Sure, it has the ‘look’ but consider whether they’re really experts in all those fields.”
Case study: ITV Central Studios
Commercial TV studio ITV Central holds debrief sessions with reporters in the field via two custom-fitted meeting rooms. Staff use a range of VoIP services including Google Hangouts, accessed via a Symetrix Radius AEC (acoustic echo cancellation) system supplied by CUK Audio and installed by integrator Involve.
Wireless tablets are used for dialling and volume control, with sound captured by hanging microphones.
Room users can also connect laptops or other mobile devices to the Dante network via an Atterotech unDUSB USB-Dante bridge. USB and VoIP can run concurrently, with the Symetrix Radius acting as a bridge.
