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White Mark is an acoustic consultancy known for its work in both the music and post production sectors, but is also heavily involved with what managing director David Bell calls the "educational" market. Radio and television studios and even specialist esports venues, as well as music recording facilities, are now a key part of schools, colleges and universities. Bell cites the Confetti Institute of Creative Technologies, part of Nottingham Trent University, as an example of a studio building with a high degree of sound isolation.

“Part of this comes from the layout created, allowing spatial separation of the rooms and the concrete block construction that was possible," he says, adding that acoustic treatments such as specialist suspended ceilings can also offer economic solutions for the absorption of sound, particularly in dealing with low end frequencies.

While the aim is to create something that is close to, if not on the same level as, a professional studio, Bell observes that the principal thing limiting the quality of acoustic spaces in education is procurement.

"Price has frequently become the only issue considered and there is a steadily decreasing consideration of what the performance will be," he says.

"Too often the procurement department will consider that professional standards of performance are too expensive. This is not the case and the use of non-application specific acoustic designers, in concert with the limited standards set out in BB93, often leads to the design/build approach elevating budgets to the detriment of the final facilities' quality."

Reverberation Factor

The amount of reverberation in a space is a key factor in the acoustic design of a studio, but it should also be high on the list of priorities when it comes to AV installations such as meeting rooms, classrooms and public places; including bars, airports and shopping centres. A low reverb time plays a part in reducing the amount of reflected sound, which can adversely affect the intelligibility of speech.

If this is not addressed as part of the initial construction, it is possible to deal with reverberation problems retrospectively by installing sound treatments. These are able to absorb or deflect unwanted audio elements to produce clearer, more intelligible sound. Among the specialist companies producing treatment systems for education and office

7 Series Master Reference Monitors environments are Ecophon and Standapart: the former offers a range of free-hanging units and baffles, modular ceilings, acoustic plaster and wall panels/screens; while the latter also produces acoustic screening, wall-mounted blocks, freestanding units and standalone 'pods' that can be installed in a larger room to create an isolated space.

Pro audio and musical instrument retailer Thomann has produced an online guide to acoustics that is primarily for what it calls 'home recording enthusiasts', but which is a useful starting place for the uninitiated. Reflections are identified as a major contributor to poor audio quality, causing comb filter effect distortions, room modes, flutter echoes and other problems. To combat these, the use of absorbers such as compressed glass fibre matting and Basotect foam, as well as plate resonators and diffusers, is recommended.

Grand Designs

In these days of grand design architecture and interiors, acoustics can often be a secondary consideration. Many architects and interior designers would no doubt baulk at the idea of putting acoustic baffles or panelling into a swanky hotel lobby, highend store or exclusive restaurant, but David Yates, founder and chief executive of technology design practice Recursive Digital, comments that simpler, less obtrusive methods of absorbing wayward frequencies and sounds can be employed to achieve a good quality outcome.

"If somewhere has been built from scratch you can specify something traditional, like acoustic ceiling panels," he explains. "If you're lucky, the interior design works with that and there might be other interiors to absorb sound, which helps beyond the standard acoustic tool kit. You could have absorbing panels in the walls but you can also put them under tables or change the furniture, for example from wooden seating to something with cushions. If you're trying to fix the reverberance in a space, sometimes you need to be a lot more creative."

While a completely dead acoustic is a very strange environment, there is a need to control the behaviour of sound in any space where audio intelligibility and, or, quality is desirable. "On the whole, reflections are bad news," acknowledges Neil Grant, managing director of acoustic consultants Harris Grant. "But absorption is difficult. No single panel is absorbent across the whole range of frequencies and if you make the room dead, you're doing nothing about mid and low reproduction."

Devices And Techniques

As Grant outlines, there are several devices and techniques available to deal with reflections and help create the right acoustic for the job. Key among these is the diffuser, a panel with a non-uniform (in other words, not flat) surface, which prevents direct reflections. A variation on this is the diffractal, usually used to control the low end and often in the form of a layered wooden diffuser.

When it comes to sound isolation/proofing, Grant says just having a concrete box structure is not enough. "You can't decouple from that, so you need a set-up of mass [outer wall, floor or ceiling], air in between, and mass [inner wall, floor or ceiling]," he explains.

Harris Grant made its name designing recording studios. One of its notable achievements is Peter Gabriel's Real World, which broke convention by having no physical divide between the control room and the performance area. Grant observes that while the recording market has changed dramatically over the last 30 years – with many big name studios either going out of business or turned into much more lucrative real estate, such as apartments – the need for good acoustics and sound in other areas has become more recognised.

"In schools and colleges there is a need to link together multiple spaces, like classrooms and music facilities," he says. "In large rooms like that, the main issue is high background noise levels. My job is to integrate things like that. Home cinema has its own rules because you're creating a false environment, with surround/immersive audio formats from 3.1 or 5.1 to Dolby Atmos."

There is a wide range and variety of acoustic treatments and constructions available at the current time, so selecting the right one for a specific project is crucial. All of the experts agree that not only should time and money be allocated to include an acoustician in the design and building processes, but also state that the clients and architects/designers need to be made aware of the niceties of acoustic design. In this way, a good sounding as well as good looking result is more likely.

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