Location: Shure Incorporated, 5800 W. Touhy Ave, Niles, IL 60714
Moderated by: Charles King
Speaker(s): Knowles Electronics
DESCRIPTION:
Balanced armature transducers (also known as receivers) are a loudspeaker commonly used in hearing aids, hearables, earphones and in-ear monitors. The presentation will give an overview of the balanced armature drivers, how they operate, and will be followed by an introduction to the simulation techniques that can be used to evaluate their performance.
Electrical and acoustical measurements are very reliable and can define the input and output from a real device or a simulation. These results help ground a simulation and ensure it is behaving like a real device. Full validation of the internal portion of the model can be difficult: these are very small devices, designed to fit inside the ear canal, and thus measurement of some very basic quantities can be physically difficult.
Just like traditional loudspeakers, dynamical analogies and SPICE simulations can simply model complete linear systems in the frequency domain. This is computationally very fast and can provide insight into the electrical, magnetic, mechanical, and acoustic components.
Finite element solvers can be used to model stiffness, mode shapes and magnetic non-linearity. As FEA contains the actual part geometry and non-linear material properties, it is well suited to study how the device will function under a static load. Often these solutions will have millions of degrees of freedom and can take a long time to solve.
Algebraic differential equation solvers can be used to combine SPICE, FEA, and measured data into a single simulation. With this tool, the amplitude response, frequency response, and distortion caused by the non-linearities can be studied.
The talk will examine strengths, weaknesses, and appropriate application of each of these individual techniques.
ABOUT THE PRESENTER:
Charles King is a Sr. Principal Engineer at Knowles Electronics in Itasca. He has worked for 20 years in research, simulation, product design and testing of a wide range of specialty transducers; developing products ranging from large outdoor warning sirens to ultra-miniature speakers used in hearing aids and in-ear monitors. He has designed balanced armature receivers, voice coil loudspeakers, compression drivers and horns as well as working with condenser microphones and optical devices. Prior to his formal engineering career he could be found in less formal locations as a live sound engineer. Charles has several patents, a degree in Electrical Engineering from California Polytechnic State University in San Luis Obispo, and previously served as Chair of the Chicago Section of the Audio Engineering Society.
Other Business: Dinner (optional, but please RSVP) will begin at 6:30pm. Contact Giles Davis ([email protected]) by Tuesday, May 29th if you would like to join us. Pizza and salad from Lou Malnati's will be provided. Please let Giles know if you have a preference for vegetarian, gluten-free, etc. Price is $10 for non-members and $8 for members and students (please bring cash).
Posted: Wednesday, May 16, 2018
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