A filter network that is designed to exhibit a predetermined passband ripple, in exchange for which, it provides more rapid attenuation above the cut-off (-3dB) frequency.
A crossover that allows some signal ripple in the pass band but allows an attenuation slope that is steeper than a Butterworth design.
Chebyshev filters, are analog or digital filters having a steeper roll-off and more passband ripple than Butterworth filters. Chebyshev filters have the property that they minimize the error between the idealized filter characteristic and the actual over the range of the filter, but with ripples in the passband. This type of filters is named in honor of Pafnuty Chebyshev because their mathematical characteristics are derived from Chebyshev polynomials.