The present invention relates to an ultrasound multi line dynamic receive focusing beam former that is part of an ultrasound system, where the beam former of the present invention resolves conceptually the, in the prior art dynamic receive focusing beam formers, by fundament, internally generated distortions, which (in the prior art), become internally generated by the beam former process itself. These distortions within prior art beam formers, typically compromises, to some degree, the ability of accurate detections after the dynamic receive focusing beamforming. The present invention advantage is an ultrasound system capable of very accurate focusing selectivity with a high dynamic range, and very low signal distortion, therefore capable of, for example, a clear detection of harmonics and super harmonics, due to the fundamentally absence of internal distortion-generation. The scope of the present invention is to resolve several, in prior-art, mentioned issues above, to provide computational efficient systems and methods capable of detecting the applications-features, very accurate and at high speed, utilizing the distortion free ultrasound Retrospective Transmit focus capable, multi-line dynamic receive focusing beamforming, which can be realized in hardware or software, wherein instead of 1d time domain processing, also 1d frequency domain processing might be utilized, suitable for other modalities that need longer detection lengths (like coding in Tx sequences).