This presentation will show you how to design and implement FIR filters with an interesting and desired variation of its spectrum. The Remez (or FIRPM) filter algorithm designs FIR filters with selectable and different constant level pass band ripple and constant level stop band ripple. This is what the recursive elliptic filter does. In an alternate design we modify the Remez to replace the constant level stop band attenuation ripple with a 1/f spectral decay. Why would we do this? We do it to protect our signal passband from stopband aliasing levels when we reduce sample rate after reducing signal bandwidth. Come by and listen, I will show you why and how and demonstrate the advantages of using this option.