144th AES CONVENTION Poster Session P06: Posters: Transducers

AES Milan 2018
Poster Session P06

P06 - Posters: Transducers

Wednesday, May 23, 16:00 — 17:30 (Arena 2)

P06-1 Acoustic Power Based Evaluation of Loudspeaker Distortion MeasurementsCharalampos Ferekidis, Ingenieurbuero Ferekidis - Lemgo, Germany
Traditionally, drive-unit related distortion figures are evaluated “on-axis.” This method leads to straightforward results as long as the frequency of the analyzed distortion component stays below the driver’s modal break-up region. When the distortion component is entering the drive-unit’s break-up region an on-axis based distortion analysis approach can become difficult if not meaningless. Therefore an alternative method is proposed which makes use of acoustic harmonic distortion sound power values, instead of sound pressure levels acquired in a single observation point (on-axis). These acoustic power values are derived from high resolution directivity data for the fundamental-, 2nd- and 3rd-harmonic-distortion components. Results are shown for different kinds of drive-units and the implications are discussed.
Convention Paper 9914 (Purchase now)

P06-2 Anti-Rattle System Loudspeaker DeviceDario Cinanni, ASK Industries Spa - Monte San Vito, AN, Italy; Carlo Sancisi, ASK Insustries Spa - Monte San Vito, Italy
On the basis of loudspeaker cabinets and panels vibration problems, this paper deals with a new dynamic loudspeaker device capable to reduce mechanical vibrations transmitted to the panel where it is fixed. Virtual 3D prototype is designed and optimized by simulations. Simulations were carried out using analytical and finite element methods. A working prototype was realized, measured and then tested on a panel, in order to evaluate vibrations reduction.
Convention Paper 9915 (Purchase now)

P06-3 FEM Thermal Model of a Compression Driver: Comparison with Experimental ResultsMarco Baratelli, Faital S.p.A. - Milan, Italy; Grazia Spatafora, Faital S.p.A. - Milan, Italy; Emiliano Capucci, Faital S.p.A. - Milan, Italy; Romolo Toppi, Faital S.p.A. - Milan, Italy
A complete time domain thermal model of a compression driver was developed using COMSOL Multiphysics in order to predict heating phenomena and minimize potential damage. Heat transfer in the model relies on conduction, natural convection, and radiation all together ensuring a rigorous approach. Considerations accounting for power compression are also included in order to provide detail in the temperature prediction through time. Results are satisfactory and represent the outcome of an accurate method to predict operation limits of such devices, together with the change of magnetic induction in the air gap due to thermal effects.
Convention Paper 9916 (Purchase now)

P06-4 Dynamic Driver Linearization Using Current FeedbackJuha Backman, Genelec Oy - Iisalmi, Finland; Noiseless Acoustics - Helsinki, Finland
It is well known that the electromechanical parameters of a dynamic driver can be modified through current feedback to suit the requirements of the available enclosure size and desired bandwidth, with a reduced distortion as a commonly observed beneficial effect. However, especially when designing sealed enclosures it is possible to select the loudspeaker parameters from a continuum of combinations of effective moving mass, damping resistance, and compliance. This paper describes optimization of electrical source parameters to improve the linearity based on numerical solution of the nonlinear equation of motion of the driver using the measured driver parameters.
Convention Paper 9917 (Purchase now)

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