A popular application for microphone arrays is speech pick up in situations where a close spacing between talker and microphone is not suitable. A beamformer is used to achieve a directivity pattern that maximizes the ratio between the desired signal and noise sources. Here a fixed beamformer is evaluated. A fixed beamformer means that the coefficients are set at one time and then remain constant. Many design methods are known for fixed beamformers. Most of these methods assume ideal microphone array characteristics like precise sensor positions, perfect phase and gain of the sensors, and free-field conditions of the acoustical field. In many practical applications these conditions are not fulfilled. The disregard of the free-field condition in some speech pick-up applications (e.g., array on the top of a monitor, array as a hearing aid) especially can cause severe distortions of the desired beam pattern. This presentation suggests an approach that includes the nonideal effects in the design process of the beamformer. The directivity pattern is therefore measured at some discrete angles. The measured data are then compared with a predetermined directivity pattern and the beamformer coefficients are optimized such that this pattern is approximated as closely as possible.