Design of long FIR-equalizers in the frequency domain

The design of FIR-equalizers approximating arbitrary e.g. measured frequency domain specifications is considered. It is shown that the frequency sampled least-square error may be found without iteration and that the coefficient matrix of the normal equations is a Toeplitz matrix making it possible efficiently to solve the normal equations with the Levinson algorithm. By this it has been possible to design a digital FIR equalizer for a loudspeaker system with `don´t care´ frequency bands and with as many as 400 tap coefficients and 800 target specifications. The CPU-time consumption has been less than 10 min. on a personal computer