When we intend the whole‐space stereophnic system, we must design this system to be simulated for original listening conditions. For this purpose, we need several equalizing networks [M. R. Schroeder and D. Gottlob, J. Acoust. Soc. Am.56, 1195–1201 (1974)]. Since these equalizers have rather complicated responses, we constructed them by digital systems. The digital equalizers described here have a form of digital filter which presents the best mean square approximation. To determine the coefficients of these filters, a direct approximation technique of log magnitude response for digital filter, proposed by I. Imai [IEEE Trans. Acoust., Speech Signal Process.25, 127–133 (1977)], was utilized. The resulting digital equalizers are recursive type and realized in a cascade connection of very simple second‐order‐type recursive digital filters (number of multipliers is two in this second‐order type filter). These equalizers have several important advantages, i.e., fewer multipliers are needed in these constructions, since we used the multipliers in time sharing fashion. And these equalizers result in easier control of the characteristics of the system.