An account of an acoustic newbie's journey from bare walls to a wellbalanced, sonically pleasant space.
The physics of the propagation of sound is immensely complicated, and when the assortment of materials that make up the walls, floors and ceiling (plus any windows, doors and furniture) are added to the equation, it's very difficult to predict what will happen to sound waves once they've left their source. What's more, every room is different, and it's not just the dimensions that will dictate how the room will sound... Imagine two rooms of the same shape and size. One has twometre-thick concrete walls, and the other a singlelayer plasterboard stud-wall. Even with those brief, albeit extreme descriptions, you probably know already that the two rooms will sound very different. Add in the multitude of room shapes, sizes, wallconstruction methods and surfaces found in home studios, and it becomes impossible to provide a one-size-fits-all guide to acoustic panel treatment.
The subject of acoustics is regularly discussed in SOS, but plenty of readers still ask for the subject to be covered from a much more basic starting point. What follows is a look at installing acoustic treatment from a complete beginner's perspective: some basic, essential information, along with a bit of advice from acoustics professionals that should give you the confidence to get started. I'll follow this up by taking you step by step through my own recent experience of treating a room.
First Things First
The first thing to grasp is the outcome you want to achieve. It's a common misconception that acoustic treatment with acoustic ceilings or acoustic baffles should kill all reverberation, and that you want a room covered floortoceiling with foam tiles: this isn't what you're aiming for. You also need to bear in mind the limitations imposed by space and budget: most home studios are small in comparison with the Abbey Roads and AIR Lyndhursts of this world, and many homestudio owners simply don't have the funds for bespoke treatment solutions.
So what is the aim? Andy Munro, acoustic design specialist, remarks, "acoustic design is the science that restores a neutral sound balance”. Applying that science means interfering with the path of sound to control the sound energy. Jorge Castro, chief acoustician at Vicoustic, says that "in the case of affordable treatment, we need to control the energy of the sound first. Then we can take care of the sound quality. With small spaces, bass frequencies are always a problem, and we should control the low frequencies as much as we can.” In fact, he continues, "In small rooms, I've never heard people saying they have too much absorption of low frequencies.”
Absorption & Diffusion: What, Where, Why?
To achieve the right balance, there are two main approaches: absorption and diffusion. Products that have absorptive properties include foam and rigid mineral-wool (see the 'DIY & Rockwool' box), and they 'soak up' the sound energy, turning it into heat, through friction. Most effective on highfrequencies, absorption is essential for reducing flutter echoes and for taming brightsounding or 'ringy' rooms. Bass trapping is also a type of absorption, but is specifically designed to absorb lowfrequency energy. A clever combination of soft, hard, thick and thin materials, including air, is used to make the most efficient bass trap, and an empty gap between the wall and the back of the trap helps to make it even more effective.
Diffusion is the scattering of sound energy using multifaceted surfaces. Diffusers are commonly made of wood, plastic, or even polystyrene. Jorge Castro explains: "diffusion helps in energy control and improves the sound quality in frequencies throughout the middle and high range of the spectrum, and also improves sweetspot image.” The 'swee
The space in question included an area that would provide a reasonablesized live room, and another that would serve as a small control room, and although both were important, I really wanted to get the performance space right. I decided that I'd buy commercially available panels, because I simply didn't have the time, space or inclination for the DIY option. Most manufacturers of acoustic products also offer a consultation service, and they often have free online calculators to help you decide on a suitable treatment option, too, so even if you choose the DIY route this can be a sensible place to start, and fabric acoustic panels are also available.
I chose to get my treatment from Vicoustic, a company relatively new to the UK acoustictreatment market who make a range of products for studios and home theatres. I told them that, as this was the only live room for a small project studio, it needed to be quite versatile, with both a 'dead' corner for dry recordings and a more ambient space to liven up acoustic recordings where needed. I'd expected a solution with almost complete wall coverage, foam panels and