Music Teaching Studios

Teaching is difficult at the best of times. But nowhere is the acoustic space more important than in a music teaching studio. Teachers spend countless hours inside small cubicles where they are subjected to ‘varying degrees of musical talent' all day long and somehow expected to provide a ‘smile plus a fresh and enthusiastic lesson' each and every time.

Most music teaching studios share the same set of problems. Because they tend to be clustered down hallways in music schools, they are usually small spaces that suffer from poor acoustics as echo ricochets off the walls. The acoustics are further eroded by the room geometry which causes the resonant frequencies to either combine or cancel each other out depending on the sitting position. These rooms wear on the nerves, will cause certain instruments to sound shrill or out of tune and results in ear fatigue, forcing the brain to work extra hard to compensate.

Then of course there is the distraction from the drumming next door pounding through the walls making it impossible for the classical guitar student to concentrate. All too often, music studio room construction follows typical home or office designs whereby the walls are not intended to cope with high sound levels. Only after the rooms are built do these problems surface and then after-market solutions need to be implemented. This is where Primacoustic comes in…

Acoustic treatment

Think of firing up your lawnmower in your garage. What happens? It becomes unbearably loud as the engine roars, quickly overwhelming the room's ability to cope. Go outside, and the noise seems to be much less irritating. But if the engine is just as loud as before, what happened? Simply put, you have eliminated the reflective boundaries. The sound is being absorbed by ‘open space' instead of reflecting back at you. A music practice room behaves exactly the same way. Left unchecked, the sound in the room will exceed the room's ability to absorb it and the energy quickly overwhelms the space. It becomes loud and uncomfortable.

The solution is easy: Treat the wall surfaces with absorptive acoustic panels. These effectively absorb sound energy in the room and make it a more comfortable place to work. Because there is less energy left in the room to resonate, the walls do not have to work quite as hard.

Selecting the right acoustic panel for the task begins by considering what frequencies you are attempting to control. A major error that many studios make is that they will install some low-density foam that will have no effect on the problem frequencies.

This diagram shows some of the common instruments that are being taught and their relative frequency range. For instance, a drum kit has a very wide frequency range when you factor in the bass drum, snare and cymbals. It follows that absorbing a broad frequency range will require a greater investment than if you are merely trying to control the sound of a flute, violin or acoustic guitar.

If we take a minute to compare two acoustic panels: a Primacoustic Broadway 2-inch with a common urethane panel, you can immediately see that the urethane panel is unable to absorb much energy below 300Hz which means that it will only be practical for instruments that play in the upper registers.

Controlling the sound of a drum kit or an electric bass guitar requires extra attention due to the greater low frequency content. This can be done using thicker Broadway 3” panels or adding bass traps like the Cumulus tri-corner trap. Both are effective at attenuating low frequencies which cause modal distortion and are easily added later on if added bass control is required.

It is also important to note that too much acoustic treatment can cause a new problem. The sound of the instrument needs to develop within the space. A completely dead room may work well with a drum kit, but it can completely ruin the sound of a violin or classical guitar. These instruments need some natural ambiance. For instruments that need natural ambiance, a good rule of thumb is to apply 15% to 30% wall treatment. This generally eliminates flutter echo while still retaining enough room ambiance to make the space comfortable.

Panel placement

One of the ‘realities’ of being in a small room is that walls tend to get banged up as instruments are brought in and out and chairs are moved around. It is therefore a good idea to put the panels up higher, out of harms way where they will less likely to get damaged.

To get the most out of the panels, always start by treating the corners. Sound naturally migrates to corners and because nearby walls reflect energy, capturing the reflections as early as possible means you will enjoy a greater degree of performance without any added cost.

Finally, since most practice studios are rectangular, try spreading the panels around in such a way that opposite walls have treatment on opposing sides. This lowers installation cost and helps eliminate flutter echo without over deadening the room.

Containing Sound

If you are planning to build a series of teaching rooms, you have the advantage of being able to plan out your rooms and construction for maximum sound isolation. The preferred approach is to employ offset wall construction which is covered at the end of this document. But since most teaching studios are preexisting, let’s first discuss the realities of what you have to work with and what you can do to improve the situation.

‘To stop sound… you need decouple and add mass!’

The problem is common. As soon as the drumming starts, the rest of the teaching rooms suffer. This is caused by the powerful energy that drums produce. In fact, the lower (and louder) the frequency, the more difficult it is to contain.

Start by looking at the ceiling. If you have a simple T-Bar construction, you can be sure that the drum sound is passing right through the ceiling tiles, going up into the plenum (air space above the ceiling tiles) and coming back down into the hallway and adjacent rooms. This is because ceiling tiles have no mass and are therefore incapable of stopping sound. Broadway Thunder Tiles offer a ready-made solution: these are special ceiling tiles that combine a high-performance glass wool absorbing surface with a gypsum board backing. The gypsum adds weight which creates a more difficult barrier for the sound to travel through.

Now the door: If you have hollow core doors, they have no mass and therefore you will have the same problem as above; the sound will pass right though. Used building supply outlets often carry a wide selection of low-cost exterior doors made from solid wood. These are often sold with the door frame which is usually equipped with weather stripping. Point being; stop the air from leaking out and you will stop more sound.

The next challenge is the walls. Most feel that a comfortable working level for teaching is about 50dB of background noise. So depending on the sound level next door, you will have to adjust your level of treatment. For instance if a drummer is playing and the sound inside his room is 100dB, the wall must attenuate the sound by 50dB to reach your desired goal.

Herein lies the problem: Most teaching studios are separated by a stud frame wall with gypsum board on both sides. This type of wall will attenuate sound by about 25dB. As our goal sis 50dB, this will only get us half way there.

The solution is to build a ‘floating wall’ in front of the existing one by using what is known as resilient channel. Resilient channel creates an air space and a ‘spring’ whereby the outer sheet of gypsum floats on top of the wall, effectively decoupling the two. This significantly increases sound blocking without having to rebuild the wall from scratch and so long as you double the mass, it will likely double the wall’s performance so that you can achieve the target 50dB reduction.

Building an offset stud wall

For new construction, the most effective ‘preventative measure’ is to build what is known as an offset stud wall whereby the floor and ceiling plates will be wider to accommodate two sets of studs. Only one set of studs is used to attach the gypsum board on each side of the wall effectively creating two walls in only a slightly larger space. The gypsum board is generally doubled up to increase mass. This is further improved upon by varying the thickness (and mass) of the gypsum board on each side so that they two walls do not vibrate in sympathy.

You can even take this one step further by introducing a heavy limp mass inside the wall commonly known as a ‘barrier’. This is typically a barium impregnated PVC that weights about 1lb. per square foot that is loosely suspended in between the walls. This adds a limp mass that will not resonate to further attenuate sound. This approach is commonly used to build recording studio walls.

Summary

Controlling sound in a music studio requires a multi-pronged approach that combines controlling the sound inside the room while doing what you can to contain the sound in the room from escaping. Broadway panels provide an effective means at reducing the sound energy inside the room which not only makes it easier to control sound, but provides numerous benefits to the teachers and students. This includes more comfortable working environment, better sounding instruments and ultimately a more enjoyable experience.

Determining Coverage

To determine the coverage, we have created a series of easy-to-use tables that enable you to choose between various degrees of treatment depending on your budget and the desired outcome. Most facilities find that a ‘light’ level of treatment provides sufficient sound abatement while keeping the budget in check. If budgets are tight, start with minimal treatment and then add more panels as funds become available.