AES Store

Journal Forum

Reflecting on Reflections - June 2014
1 comment

Quiet Thoughts on a Deafening Problem - May 2014
1 comment

Perceptual Effects of Dynamic Range Compression in Popular Music Recordings - January 2014
5 comments

Access Journal Forum

AES E-Library

Modeling a Loudspeaker as a Flexible Spherical Cap on a Rigid Sphere

It has been argued that the sound radiation of a loudspeaker is modeled realistically by assuming the loudspeaker cabinet to be a rigid sphere with a moving rigid spherical cap. Series expansions, valid in the whole space on and outside the sphere, for the pressure due to a harmonically excited, flexible cap with an axially symmetric velocity distribution are presented. The velocity profile is expanded in functions orthogonal on the cap rather than on the whole sphere. This has the advantage that only a few expansion coefficients are sufficient to accurately describe the velocity profile. An adaptation of the standard solution of the Helmholtz equation to this particular arametrization is required. This is achieved by using recent results on argument scaling in orthogonal Zernike polynomials. The efficacy of the approach is exemplified by calculating various acoustical quantities with particular attention to certain velocity profiles that vanish at the rim of the cap to a desired degree. These quantities are: the sound pressure, polar response, baffle-step response, sound power, directivity, and acoustic center of the radiator. The associated inverse problem, in which the velocity profile is estimated from pressure measurements around the sphere, is feasible as well since the number of expansion coefficients to be estimated is limited. This is demonstrated with a simulation.

Authors:
Affiliations:
AES Convention: Paper Number:
Publication Date:
Subject:

Click to purchase paper or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member and would like to subscribe to the E-Library then Join the AES!

This paper costs $20 for non-members, $5 for AES members and is free for E-Library subscribers.

Learn more about the AES E-Library

E-Library Location:

Start a discussion about this paper!


 
Facebook   Twitter   LinkedIn   Google+   YouTube   RSS News Feeds  
AES - Audio Engineering Society