The effects of loudspeaker azimuth and reference microphone location on probe tube microphone measures were assessed. The real ear unaided response (REUR), real ear aided response (REAR), and real ear insertion response (REIR) were obtained on a KEMAR. Aided measures were obtained with both a behind-the-ear and an in-the-ear hearing aid. All three measurements were affected by changes in the lo...

This paper provides recent developments in modeling and identification of nonlinear systems pertinent to loudspeaker with nonlinear distortion effect. It is known that when small loudspeakers are driven at high playback levels the nonlinear characteristics of these speakers become a major source of sound degradations. Consequently it is essential to find a good model that matches to the loudspe...

Sound field reproduction methods based on orthogonal expansions like e.g. higher order Ambisonics always introduce a limitation of the spatial bandwidth of the loudspeaker driving signals. As a consequence, the desired component of the reproduced wave field is similarly bandlimited. This leads to a pronounced sweet spot around the center of the loudspeaker distribution. This area is sweet both ...

Signal distortions caused by loudspeaker nonlinearities can be compensated by inverse nonlinear processing of the electric driving signal. This concept is based on an adequate control architecture having free control parameters adjusted to the particular loudspeaker. Optimal performance requires a self-tuning (adaptive) system to compensate for variations of loudspeaker parameters due to the ef...

Piezoelectric loudspeaker is characterized by its very simple constructions, but their radiation performance at low frequency region is poor because their conventional diaphragm is too stiff for large amplitude vibration. This paper proposes three innovative methods for improvement of low frequency radiation performance of piezoelectric direct-radiator loudspeakers by new constructions and mate...

In this paper, we present the theoretical basics and implementation strategies for sound field reproduction using circular and spherical loudspeaker arrays. The presented approach can be seen as an analytical formulation of what is known as higher order Ambisonics. It relies on the assumption of a continuous distribution of secondary sources on which sampling is performed to yield the loudspeak...

In this paper, an electrodynamic planar loudspeaker driven by a digital signal is experimentally discussed. The digital loudspeaker consists of 22 voice coils, 11 permanent magnets, a diaphragm with streamlined sections molded in plastic, and a suspension made of handmade Japanese paper between the diaphragm and the frame. First, the acoustic responses are affected by the arrangement of the voi...

A review of the current state of parametric loudspeaker from the aspects of modelling, measurement, signal processing, implementation and applications is presented in this paper. A variety of well-established and emerging numerical methods to predict the propagation of finite amplitude sound beams are discussed and compared. The accurate measurement of the difference-frequency sound is another ...

II. THE ADAPTIVE PRE-DISTORTION SCHEME This paper presents a new and promising application for adaptive nonlinear filters adaptive linearization of a loudspeaker. In a loudspeaker, the nonlinearity in the suspension system produces a significant distortion at low frequencies and the inhomogeneity in the flux density causes a nonlinear distortion at large output signals. These distortions should...