13 February 2023
In the March issue of audioXpress distributed February 10 2023, I present two new Balanced Armature Receiver (BAR) lumped models. I have already discussed one of the models in a previous blog post, where the 'Single' BAR lumped model outputs were shown to closely match those of a finite element model for both electrical, structural, and acoustic variables.
The model is also capable of showing the difference between a clamped vs a free hanging 'Single' BAR, which I had shown in the months leading up to the blog post mentioned, and it could be seen how the fundamental resonance frequency is lower in the 'fixed' situation than the 'free'; this can be also be observed in measurements.
My work sparked some interest in the industry, so I have continued down this BAR path on and off (mostly off) since. With the article out, an additional new model is presented for the so-called 'Dual' Balanced Armature Model. The 'Dual' has 'two of everything', meaning armature, membranes, and additional parts, except for the housing being shared as well as the front chamber being a single volume seen by both membranes. The acoustical part can again take into account the (axially) housing movement , but this happens only where there is asymmetry between the two receiver section.
Again. the 'Dual' lumped model has been compared with a Finite Element model in COMSOL Multiphysics, and there is the same excellent agreement between lumped and FEM results. As with the 'Single' BAR model, the effect of the whole housing moving are included in the model with respect to force distribution as well as acoustic outputs , which is not the case for the traditional models available in the literature.
A journal paper presenting these models and more is done, but for now check out the audioXpress article. If anybody wants more details on these new models, feel free to reach out at email@example.com. For Danish companies, I can potentially pop by and explain the models, just shoot me a mail.
For those interested in learning how to do lumped modelling or other types of modelling and simulation, check out my new Services Portfolio document (https://www.acculution.com/_files/ugd/a0aa2c_d507fda717ad473689a6dfbb0fdedf58.pdf) where training is one of the options for companies.