Studio soundproofing materials that absorb sound act like sponges soaking in most of the sound waves striking them. Although all materials — whether porous, semi-porous or solid — absorb some portion of a sound wave, the terms “acoustic panel” or “acoustic material” refer primarily to materials developed for the purpose of offering optimal sound absorption values. Because music studio sound proofing absorbers reflect little, if any, sound energy striking them, they are useful for controlling unwanted noise and reverberation.
A wide variety of eco-friendly sound absorption materials exist today that provide different sound reducing properties for soundproofing a studio. The best studio attenuation materials are porous — i.e., material containing tiny channels, cavities or intervening spaces allowing for the passage and absorption of sound waves. Most porous, sound absorbing materials are classified as fibrous, granular or cellular and work to reduce noise clutter and reverberation by dissipating sound waves through friction with air molecules moving inside pores.
One of the most frustrating aspects of sound is that it will go where it wants to, and find its way through any space via any available path. That’s why it’s so important (and so difficult) to block any potential points where sound can leak through. In all cases, mass is your friend – the thicker and more dense your walls are, the better they’ll be at stopping sound..
Soundproofing materials may or may not work as effectively as you want them to work. The main principles of soundproofing are conduction/space, mass, isolation, absorption, and dampening. Space is easy to understand: the farther away something noisy is, the less noticeable the sound. Solid mass objects work to block sound waves by simply stopping the path of sound waves. Sound waves hitting a solid mass bounce off and essentially “die,” leaving the other side of the solid mass quieter. Isolation or decoupling creates structural breaks in the path sound is traveling. Isolation is the key to stopping structural borne sounds and heavy vibrations. Absorption materials suck up sound like a sponge. Porous foams and cotton-based materials are very common sound absorbers. They are very effective at trapping sound and minimizing sound reflection. Dampening materials dissipate sound energy. These materials are visco-elastic in nature and dissipate sound energy by reducing resonance.
Studio Soundproofing typically utilizes multiple types of sound control. Sound control materials used to stop transfer into or out of the space are typically implemented during construction of a building or later as part of a renovation project. Mass and Isolation are the most common soundproofing methods used in construction or remodeling of studios. These materials are utilized within the wall, ceiling, and floor assemblies. Sound Absorption materials are typically used to treat the space acoustically after construction or remodeling of the walls, ceiling and floor assemblies is completed. Porous foam, cotton, or fiberglass panels are mounted on the wall and ceiling surfaces to minimize reverberation and create an acoustically sound environment in the studio.
Although porous sound absorbers like acoustic fiberglass do not block sound waves, they substantially minimize noise clutter by de-energizing sound waves as waves encounter heavy friction between fibers. This type of sound absorber not only reduces sound levels within a recording studio, but also decreases echoes, reverberation times and stops focusing of noise reflected off curved surfaces.
The science of acoustics is something that tends to alternately baffle and intimidate most of us. Outside of a handful of highly trained individuals, the aspects of what makes a room sound a certain way is looked upon as a sort of black art. Performance venues and upscale recording studios routinely include acoustic designers in their construction budgets, spending considerable sums of money in pursuit of sonic perfection.
But for the average musician, budgeting for acoustic treatment has traditionally ranked well below the more tangible fun stuff like instruments, mics, recording gear, plug-ins, toys and more toys. Even if you’re at liberty to physically alter your space without incurring a landlord’s wrath, budgeting for two-by-fours, sheetrock and caulking doesn’t tend to hold the same appeal as that new channel strip plug-in or twelve-string you’ve been pining for.
Fortunately, the same technological revolution that has brought multitracking into spare bedrooms and one-car garages has also created low-cost solutions for many of the common acoustical issues facing the average project studio. In this month’s Studio Basics we’ll look at some ideas to smooth out your sonic nightmares.