1. A method ( 300 ) for determining N coefficients of an asymmetric prototype filter p 0 for usage for building an M-channel, low delay decimated analysis/synthesis filter bank ( 101 , 102 ) comprising M analysis filters h k ( 103 ) and M synthesis filters f k ( 106 ), k=0,. .. , M−1, wherein M is greater than 1, and having a transfer function, the method comprising the steps of choosing ( 301 ) a target transfer function of the filter bank comprising a target delay D; wherein D is smaller or equal to N; determining ( 303 , 304 , 305 ) a composite objective function e tot comprising a pass band error term e t and an aliasing error term e a ; wherein the pass band error term e t is associated with the deviation between the transfer function of the filter bank and the target transfer function; and wherein the aliasing error term e a is associated with errors incurred due to the subsampling of the filter bank; and determining ( 306 , 309 ) N coefficients of the asymmetric prototype filter p 0 that reduce the composite objective function e tot .