Open AccessDirectional Loudspeaker Using a Parametric Array
Author(s) -
A. Ritty
Publication year - 2006
Publication title -
acta polytechnica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.207
H-Index - 15
eISSN - 1805-2363
pISSN - 1210-2709
DOI - 10.14311/862
Subject(s) - parametric array , loudspeaker , directivity , acoustics , directional sound , parametric statistics , transducer , nonlinear acoustics , nonlinear system , aperture (computer memory) , computer science , signal (programming language) , engineering , sound (geography) , physics , mathematics , telecommunications , antenna (radio) , statistics , quantum mechanics , programming language
The theory for sound reproduction of parametric arrays is based on nonlinear acoustics. Due to the nonlinearity of the air, a finite amplitude ultrasound interacts with itself and generates audible secondary waves in the sound beam. A special feature of this loudspeaker is its sharper directivity compared to conventional loudspeakers of the same aperture size.This paper describes the basis of the theory used for parametric arrays, and presents the influence of the main parameters, e.g., carrier frequency. It also describes some signal pre-processing needed to obtain the desired audible sound. A PVDF (polyvinylidenefluoride) film transducer is also studied in order to produce a prototype to confirm the theory.