19/08/2018
Room Acoustics Tips: Geometry and Sound
Walls, Ceilings, and Floors
Most people think of a room as two sets of parallel walls and a parallel floor and ceiling. As an architect, however, you probably envision something more creative. That’s good from an acoustics perspective because parallel, sound-reflecting surfaces like walls can create flutter echo.
What’s flutter echo? Flutter echo is when sound rapidly reflects back and forth between two acoustically reflective, parallel surfaces. It’s annoying.
To prevent it, change the geometry of one of your surfaces so that they are at least 10 degrees out of parallel. This will also improve the dispersion of sound throughout your room.
Convex and Concave
Concave Sound Reflection -How sound reflects off a concave surface.
In addition, try to avoid using concave shapes for your surfaces. They can cause sound reflections to converge at a focal point located at the geometric center of the curve or travel along the curve’s surface. The result? Loud hotspots within the space, or sound being carried an abnormally long distance.
If you must use a concave shape, you will likely need to incorporate sound-absorbing materials. An acoustical consultant might also be able to help you adjust the geometry of your curve to minimize noise problems.
Convex Sound Reflection - How sound reflects off a convex surface.
Convex shapes, on the other hand, diffuse or reflect sound in many directions. This is a good thing! Diffusion helps musical sounds blend, and reduces unwanted reflections. Sound diffusing shapes include:
Half cylinders, barrels, and hemispheres
Pyramids and prisms
Variously-angled surfaces, such as a saw-tooth pattern
These room acoustics tips and tricks are great a great place to start in creating your designs. An acoustical consultant, can provide customized recommendations and calculations to create ideal acoustical environments.
