AN EXTENDED MODEL FOR IMPEDANCE AND COMPENSATION OF ELECTRO-DYNAMIC LOUDSPEAKER UNITS AND AN ALGORITHM FOR THEIR DETERMINATION.

The impedance of loudspeaker units can be described by lumped-element models, which increase the efficiency and accuracy of cross-over design if applicable over the entire frequency range. We have extended current models to obtain excellent description in the entire useful range. Also, algorithms have been designed which automatically find the best parameters for the lumped-element model and a compensation network, which are easily implemented on a PC. Summary. Most lumped-element models, used for the description of the impedance of electro-dynamic loudspeaker units deviate from the true behaviour in a part of the useful frequency range. However, the design of cross-over networks can be done more efficiently and accurately using computer models, in which the loudspeaker units are replaced by their lumped-element equivalents. The accuracy of the design thus depends on the accuracy of the description of the impedance by the lumped-element model. We have therefore improved such models to describe the entire useful frequency range in order to eliminate the problem of deviation. Our final model comprises eight elements, and therefore requires automatic determination by an efficient algorithm. The major problem with such algorithms is that as the number of dimensions increases, th