The paper proposes a new digital audio coding method. This method combines subband-coding with an interpolater which is designed by using sampled-data H/sup /spl infin// control theory. This method is not only simpler to compute than the conventional one, but also takes account of the analog performance. In this system, the complicated procedures are frequency decomposition and bit allocation. For decomposing the frequency, various efficient filter banks are proposed and for signal reconstruction FFT (fast Fourier transform) is used. Moreover, a new bit-allocation method is proposed, which is simpler than the conventional method, MPEG-1 Audio. A design example is presented to show the advantages of the present method.