Block Digital Filtering (BDF) is a well known method for fast digital filtering. Indeed, it decomposes the input signal into blocks and takes profit of complexity reduction provided by the Fast Fourier Transform algorithm to considerably reduce the computational cost. In this paper, we propose a simple and efficient matrix-oriented approach to compute and visualize the frequency response of a BDF, as well as to optimise the BDF coefficients. This approach can be considered as an interesting alternative to the traditional overlap-save method, because it provides better frequency responses.