A modified frequency-response masking (FRM) approach is presented for the design of arbitrary bandwidth sharp FIR filters. The new filter achieves significant savings in the number of arithmetic operations by replacing the band-edge shaping filter in the FRM technique with a modified interpolated finite impulse response (IFIR) filter. Our example shows that the proposed one-stage FRM filter outperforms an original two-stage FRM filter in terms of the number of multipliers and group delay.