Background, Motivation and Objective Acoustical vortices are formed by helical waves rotating around the vortex core in a given direction due to the phase singularity. Based on the calculation of the acoustic intensity, it is demonstrated that the angular momentum of the acoustical vortices could be transferred to matter, which has potentials for the applications in alignment and manipulation of small object. Angular momentum transfer was determined by the ratio of the beams topological charge to its angular frequency. In previous study, big number element matrix transducer array with the phase increment of pi/4 or pi/2 are often employed to generate acoustical vortices with high topological charge. However, the relationship among source number, phase difference and topological charge has not been investigated. How to produce controllable distributions of pressure and phase with sparse sources in simple configuration is still an important topic.