1. An adaptive filter device, comprising: a finite impulse response (FIR) filter which is based on filter coefficients, which are determined based on a predetermined iterative adaptation algorithm for determining filter coefficients of an adaptive filter, wherein, in at least one iteration step of said predetermined iterative adaptation algorithm a sum value is determined, wherein at least one summand of said sum value depends on at least one of said filter coefficients, and, if said sum value is above a predetermined threshold, the filter coefficients are modified.