P3 / Reprogramming / Diagram

1 How the plan shape shape of a room affects the early reflections from the side walls

  a Narrow, rectangular rooms send reflections from the side walls to the seats.

  b If the room widens towards the rear, the sound is reflected to the rear of the room.

  c Concave plan shapes focus the soundwaves, which usually leads to disturbing concentrations of sound

2

  a The soundwave illustrates flutter echoes between parallel wall surfaces.

  b This can be avoided by designing the stage to taper towards the rear.

  c If the walls taper inwards a little, the soundwave is reflected back and unpleasant flutter echoes can be the result.

- MOMMERTZ, Eckard (2009) Music, Acoustics and Sound Insulation, Birkhäuser, p. 16