Change search
ReferencesLink to record
Permanent link

Direct link
A Method of Designing Wide Dispersion Waveguides Using Finite Element Analysis
Norwegian University of Science and Technology, Faculty of Information Technology, Mathematics and Electrical Engineering, Department of Electronics and Telecommunications.
2011 (English)MasteroppgaveStudent thesis
Abstract [en]

High frequency dispersion has a great influence on the perceived performance of a loudspeaker. The directivity of a single transducer primarily depends on driver size, however directivity can be modified using an acoustical waveguide. A method of modelling and designing a wide dispersion waveguide for a loudspeaker soft dome tweeter has been developed. A combination of finite element (FE) modelling and understanding of directivity and waveguides is used in order to prototype loudspeakers virtually. By utilizing computer simulations, the prototyping process is faster and more cost effective, all the while designing better performing loudspeakers. Firstly, a baseline acoustic-structure interaction FE model of a tweeter was built in the Comsol Multiphysics software. The model was verified by measurements, and the directional properties showed satisfactory agreement in the frequency range of interest. The accuracy of the baseline model allowed for credible simulations of waveguides. Secondly, many waveguide geometry types were investigated, and a method for randomizing geometries and automating the design process was developed using the Livelink for Matlab module in Comsol. Subsequently, a best fit waveguide design was selected based on a set of defined design criteria. Thirdly, a prototype was built, the measured performance compared to the simulated model, and discrepancies investigated. The waveguide directivity performs as modelled through most of the working range, although deviations from simulations were larger than expected at frequencies above 12 kHz. The measurements validate the modelling procedure and emphasize the value of the design algorithm, even though the prediction accuracy may be improved. It can be shown that a waveguide of this type can, with only small modifications, be an effective way to increase HF dispersion for a large range of commercially available tweeters.

Place, publisher, year, edition, pages
Institutt for elektronikk og telekommunikasjon , 2011. , 98 p.
Keyword [no]
ntnudaim:5927, MTEL elektronikk, Akustikk
URN: urn:nbn:no:ntnu:diva-14044Local ID: ntnudaim:5927OAI: diva2:445814
Available from: 2011-10-05 Created: 2011-10-05

Open Access in DiVA

fulltext(20733 kB)7727 downloads
File information
File name FULLTEXT01.pdfFile size 20733 kBChecksum SHA-512
Type fulltextMimetype application/pdf
cover(409 kB)36 downloads
File information
File name COVER01.pdfFile size 409 kBChecksum SHA-512
Type coverMimetype application/pdf
attachment(151643 kB)300 downloads
File information
File name ATTACHMENT01.zipFile size 151643 kBChecksum SHA-512
Type attachmentMimetype application/zip

By organisation
Department of Electronics and Telecommunications

Search outside of DiVA

GoogleGoogle Scholar
Total: 7727 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Total: 267 hits
ReferencesLink to record
Permanent link

Direct link