Simulation-driven Design of Loudspeaker Cabinet Using Optimization Algorithms for Finite Element Models
Authors
Olsen, Oliver Kragh Hindborg ; Johansen, Alexander Kruse
Term
4. term
Education
Publication year
2023
Submitted on
2023-06-01
Pages
69
Abstract
The loudspeaker company DALI already uses computer simulations—finite element analysis (FEA) and the boundary element method (BEM)—to design drivers and bass-reflex ports. This project shows how the same simulation-driven approach can be extended to the loudspeaker cabinet. The Rubicon 6 is used as a case study, and the procedure can be applied to other cabinets. We build a detailed frequency-domain vibration model (a benchmark harmonic analysis) that prioritizes accuracy over speed and validate it with experiments that measure cabinet accelerations using accelerometers. Based on this, we develop a faster design model that reproduces the key results of the benchmark. We then parameterize the locations of the cabinet’s internal braces and optimize them with a genetic algorithm (an evolutionary search method). The objective is to minimize the maximum equivalent radiated power from the cabinet’s external MDF panels—an estimate of how much sound the vibrating panels would radiate. The optimized design reduces equivalent radiated power compared with the current cabinet simply by repositioning the existing braces. In addition, we propose and optimize a general bracing layout, showing that no prior knowledge of the cabinet’s response is needed to achieve a design that outperforms the existing one.
Højttalerproducenten DALI bruger allerede computersimuleringer—finite element analyse (FEA) og rand-element metoden (BEM)—til at udvikle enheder og basrefleksporte. Dette projekt viser, hvordan den simulationsdrevne tilgang kan udvides til også at omfatte designet af kabinettet. Rubicon 6 bruges som casestudie, men fremgangsmåden kan anvendes på andre kabinetter. Vi opbygger en detaljeret vibrationsmodel i frekvensdomænet (en benchmark harmonisk analyse), som prioriterer nøjagtighed over beregningstid, og validerer den med målinger af kabinettets accelerationer ved hjælp af accelerometre. På denne baggrund udvikler vi en hurtigere designmodel, der gengiver de vigtigste resultater fra benchmarken. Placeringerne af kabinettets interne afstivninger parameteriseres og optimeres med en genetisk algoritme (en evolutionær søgemetode). Målet er at minimere den maksimale ækvivalente udstrålede effekt fra kabinettets ydre MDF-paneler—et mål for, hvor meget lyd de vibrerende flader vil udsende. Den optimerede løsning reducerer den ækvivalente udstrålede effekt i forhold til det eksisterende kabinet alene ved at flytte de allerede anvendte afstivninger. Desuden foreslås og optimeres en generel afstivningsstruktur, som viser, at der ikke kræves forudgående viden om kabinettets respons for at opnå et design, der er bedre end det eksisterende.
[This apstract has been rewritten with the help of AI based on the project's original abstract]
Keywords