The advancement of Field Programmable Gate Array (FPGA) technology opens up a very interesting option for rapid implementation and easy configurable signal processing platform for parametric loudspeaker system.
During the directivity measurement for the parametric loudspeaker, the proposed filter has also proved to be effective and is only needed for small angles.
In this paper, the digital signal processing subsystem of the parametric loudspeaker system has been designed and implemented in FPGA platform using the Altera 1S10 device.
Parametric loudspeaker system enables sound to be projected and directed to a specific listening area just like a beam of light.
After applying our proposed filter in the axial measurement of the parametric loudspeaker, a clear frequency dependence from parametric array effect is detected, which exhibits a good match with the well-known theory described by the Gaussian-beam expansion technique.
The spurious signal generated as a result of nonlinearity at the receiving system affects the measurement of the difference-frequency sound in the parametric loudspeaker, especially in the nearfield or near the beam axis.
