Device for calculating FIR filter coefficients for beam-forming filters of a transducer array, comprising: first calculation means for calculating frequency domain filter weights of the beam-forming filters (14 1...,14 N) for a predetermined frequency raster so as to obtain target frequency responses for the beam-forming filters, so that application of the beam-forming filters to the transducer array approximates a desired directional selectivity (36; 38; 70; 74); and second calculation means for calculating the FIR filter coefficients for the beam-forming filters so that frequency responses of the beam-forming filters approximate the target frequency responses; further comprising a target frequency response modification means connected between the first calculation means and the second calculation means so as to modify the target frequency responses of the beam-forming filters as obtained by the first calculation means, so that the second calculation means calculates the FIR filter coefficients for the beam-forming filters in such a manner that the frequency responses of the beam-forming filters approximate the target frequency responses in a form modified by the target frequency response modification means, said modification including frequency domain smoothing and/or for each beam-forming filter, leveling of a phase response, adjusted by 2π phase jumps, of the target frequency response of the respective beam-forming filter by removing a linear phase function portion, and storing a delay for the respective beam-forming filter, said delay corresponding to a slope of the linear phase function portion. first calculation means for calculating frequency domain filter weights of the beam-forming filters (14 1...,14 N) for a predetermined frequency raster so as to obtain target frequency responses for the beam-forming filters, so that application of the beam-forming filters to the transducer array approximates a desired directional selectivity (36; 38; 70; 74); and second calculation means for calculating the FIR filter coefficients for the beam-forming filters so that frequency responses of the beam-forming filters approximate the target frequency responses; further comprising a target frequency response modification means connected between the first calculation means and the second calculation means so as to modify the target frequency responses of the beam-forming filters as obtained by the first calculation means, so that the second calculation means calculates the FIR filter coefficients for the beam-forming filters in such a manner that the frequency responses of the beam-forming filters approximate the target frequency responses in a form modified by the target frequency response modification means, said modification including frequency domain smoothing and/or for each beam-forming filter, leveling of a phase response, adjusted by 2π phase jumps, of the target frequency response of the respective beam-forming filter by removing a linear phase function portion, and storing a delay for the respective beam-forming filter, said delay corresponding to a slope of the linear phase function portion. frequency domain smoothing and/or for each beam-forming filter, leveling of a phase response, adjusted by 2π phase jumps, of the target frequency response of the respective beam-forming filter by removing a linear phase function portion, and storing a delay for the respective beam-forming filter, said delay corresponding to a slope of the linear phase function portion.