Methods for filtering an input signal x(k) to produce an output signal y(k) such that the ratio of a power level of the output signal to a power level of the input signal is substantially equal to a desired value γ are provided. The methods include forming a first corrected frequency response H(ω) based on a first correction value gcorr(0) and a desired frequency response H(ω); forming a first filter h(z) from the first corrected frequency response H(ω); applying the first filter h(z) to a first block of the input signal to produce a first output signal block; computing an amplification γ caused by the application of the filter h(z); computing a value γdiff, wherein γdiff represents an amplification error; computing a second correction value gcorr(1), where gcorr(1) is a function of gcorr(0) and γdiff; forming a second corrected frequency response H(ω) based on the second correction value gcorr(1) and the desired frequency response H(ω); forming a second filter h(z) from the second corrected frequency response H(ω); and applying the second filter h(z) to a second block of the input signal to produce a second output signal block.