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A Simple Model for Forces of a Loudspeaker Driver?

Andrea Michael Cozzolino

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Hi, i'm a Wood Engineering Student and i'd like to be able to model loudspeaker enclosures as function of the mechanical coupling of the speaker driver(s) to the enclosure itself. I know there's also acoustical coupling, i prefer to keep things as simple as possible at the beginning. Now, i do have some knowledge about speakers since i built many systems in the past, with the help of other softwares like Leap. I'd like to use Comsol for this study, and i'm sure it is possible. I went through the Model Examples, there are a few about loudspeakers.. But i was wondering if i could create a simpler model in which i would define just the main parameters of the driver (thiele/small) and an input voltage, in order to create a mechanical frequency domain signal that i would use as source for mechanical stress (forces) in a given point of the loudspeaker (in my case, the flange where the driver would be fixed).
From here, as second step, i would like to use a geometry for the basket of the driver, assigning to it the material in order to include some of the damping of the driver.

Just to be clear, my goal is to analyse different materials and geometries for the loudspeaker enclosures.. therefore it would be (at least at the beginning) sufficient to have a simplified model for the mechanical stress induced by the driver. I'm looking forward to learn how to use Comsol for more accurate simulations about this, since it's going to be my job, in the future.

Thanks for the help in advance, greetings from Bavaria

A.


2 Replies Last Post Jun 11, 2019, 12:42 p.m. EDT

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Posted: 5 years ago Jun 4, 2019, 6:53 a.m. EDT
Updated: 5 years ago Jun 4, 2019, 6:53 a.m. EDT

Hello

Maybe you could take a model in the app gallery and scale them down?

For example: Loudspeaker Driver in a Vented Enclosure - The model uses the Acoustic-Shell Interaction, Frequency Domain multiphysics interface and therefore requires the Structural Mechanics Module.

Or: Lumped Loudspeaker Driver - The Thiele-Small parameters (small-signal parameters) serve as input to the lumped model.

Or just take a look at: https://www.comsol.com/models?q=loudspeaker

Just to be clear, my goal is to analyse different materials and geometries for the loudspeaker enclosures

You can do that with a material sweep and a parametric sweep :)

Hello Maybe you could take a model in the app gallery and scale them down? For example: [Loudspeaker Driver in a Vented Enclosure](https://www.comsol.com/model/loudspeaker-driver-in-a-vented-enclosure-2312) - The model uses the Acoustic-Shell Interaction, Frequency Domain multiphysics interface and therefore requires the Structural Mechanics Module. Or: [Lumped Loudspeaker Driver](https://www.comsol.com/model/lumped-loudspeaker-driver-12295) - The Thiele-Small parameters (small-signal parameters) serve as input to the lumped model. Or just take a look at: [https://www.comsol.com/models?q=loudspeaker](https://www.comsol.com/models?q=loudspeaker) > Just to be clear, my goal is to analyse different materials and geometries for the loudspeaker enclosures You can do that with a material sweep and a parametric sweep :)

Andrea Michael Cozzolino

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Posted: 5 years ago Jun 11, 2019, 12:42 p.m. EDT

Thanks for the help. I realized that the first part of this tutorial is very useful for my project. i do have a problem though. Defining the Variables (pag 15 of the examples pdf), Comsol doesn't recognize any of the variables. For the cone velocity: av_apex(shell.u_tZ) he tells me: "unknown variable shell.u_tZ" For the other 3 variables he tells me: "unexpected unit of input" . A friend suggested me that maybe there's a difference between the sintax of comsol 5 and my version, version 4. Does anybody have an opinion about this?

Thanks a lot for the help, cheers.

Thanks for the help. I realized that the first part of this tutorial is very useful for my project. i do have a problem though. Defining the Variables (pag 15 of the examples pdf), Comsol doesn't recognize any of the variables. For the cone velocity: av_apex(shell.u_tZ) he tells me: "unknown variable shell.u_tZ" For the other 3 variables he tells me: "unexpected unit of input" . A friend suggested me that maybe there's a difference between the sintax of comsol 5 and my version, version 4. Does anybody have an opinion about this? Thanks a lot for the help, cheers.

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