**8 Acoustics**

**Resonant Frequencies in Rooms**

Rayleigh’s formula for the frequencies of modes in a rectangular room:

where *n*_{L}, *n*_{W} and *n*_{H} are positive integers, including 0, *L, W* and *H are* the room dimensions and *c* is the velocity of sound.

**Modal density.** If the number of resonant modes *N* below the frequency *f* is fairly high then a reasonable approximation is given by

where | V is the volume, |

S is the total surface area, 2(LW + WH +HL) and | |

L is the sum of the edge lengths 4(L + W + H). |

**Reverberation time (RT, r.t. or T_{60})**

This is defined as the ...

Start Free Trial

No credit card required