Controlled acoustics

Materials used in concert halls, performance spaces and auditoriums.

For my interior design final honours project, I am designing a public concert hall to encourage amateur big bands as well as showing the general public a new appreciation for live instrumental music. The building I am using is Manchester's abandoned Mayfield station depot, which is over 50 by 100 meters and mainly raw concrete. My challenge is to find the right materials to adsorb unwanted sounds and emphasise the right sound where I need to.

In any large space including my building, two main things need to be done to control the acoustics to a reasonable level. Firstly the sounds from the stage needs to be directed towards the audience where possible. Secondly, pretty much all other sounds need to be muffled and absorbed to not interfere with the music/speech/performance going on.

Concert halls always make the audiences seats tiered so that people do not block the sound from getting behind them. To direct the sound waves that did not go forwards, ceilings have added acoustic boards angled to bounce the sound back down to the audience. These have to be made from a hard flat surfaced material for them to work and are often shaped into interesting designs, giving the boards an aesthetics purpose too.

Some examples of materials that would reflect sound are; wood, concrete, glass and metal. When cost and weight are factored into the decision of what is suspended above a concert hall, wood is usually used.

For the rest of the concert hall, soft, porous materials are used to absorb the sounds that shouldn't be heard and keep the clarity of every note played/word spoken on stage. There is a larger range of materials used for this depending on where it will be and the what it's required to do with the sound.

areas that need to be considered are the seats, the floor and the walls.

Walls often have fairly thick fabric weaved or ruffled and attached, or panels made from fabric stretched over foam, both help sound proof the concert hall from the noises of outside.

The floor should also need to absorb some sound to avoid hearing footsteps and other disturbances during a performance. Of course a high quality carpet will work. A cheaper option is cork underlay flooring which has several benefits that I talk about in a dedicated post.

And finally seating used in good acoustic halls should be padded, again with fabric and sponge, this obviously is comfortable as well, which is important when people are sitting for an extended amount of time.

Although my Honours project design is meant for people to perch on the seats for a shorter amount of time and because it's such a large space to fill, I am using cheap materials so for those reasons i am considering making my abstract seats from cork.