### Strutt Help

Parallelepiped Source Propagation Loss
^{1/1, 1/3}
**Strutt|Propagation|Parallelepiped** provides the correction for sound power radiated over a parallelepiped, given the length, width, height and distance in metres from the source.

This is implemented as:

`x = 10log_10(S)`, where

`S = 4[(1/2 A + r)(1/2 B + r) + (1/2 B + r)(C + r) + (C + r)(1/2 A + r)]`

Note:

This calculation assumes that the source is located on a reflective plane.
For the vast majority of situations, the conformal area calculation is more appropriate. However, some ISO standards require the use of this parallelepiped calculation.

Comments or suggestions to
strutt@arup.com