Self- and mutual radiation resistance measurement by use of the sound intensity technique

Radiated sound power from sources can be measured by use of the sound intensity technique. The radiated power is obtained by integrating the normal intensity over the surface surrounding a sound source. Since the total radiated power from sound sources is determined by self- and mutual radiation resistances, it is possible to determine the radiation resistances from the measurement of radiated power. For a sound reinforcement system, it is useful to know the radiation resistances of loud speakers in a listening room. Acknowledge of self- and mutual radiation resistances is also important for an active sound power or noise control. As an example, self- and mutual radiation resistances of two closely located loudspeakers measured in lecture room are presented. Due to reflections, the resistance curve of a piston in an infinite baffle. The effect of the loudspeaker placement on the self and mutual resistances is very significant.