Using advanced simulation and measurement tools
Ole Wolff also has the SCN-NF which adds 2pi acoustical measurement capabilities to the same Scanning Vibrometer platform used for laser scan diaphragm vibration.
The SCN hardware is extended with a microphone in addition to the existing laser sensor.
Automated axis control ensures repeatable, precise and fast positioning of the microphone and laser sensors, in combination with a round baffle for measuring transducers up to 10″ (30 cm) in diameter, or compact (smart) speakers.
Knowing the material properties and having an accurate CAD, the diaphragm behavior can be predicted in Comsol Multiphysics®. Typically the model is set up using a combination of pressure acoustics, solid mechanics, shell physics and lumped electrical/magnetic parameters.
Comsol simulation of mode at 1875 Hz shows great agreement with Klippel measurement.
Mode at 1875 Hz measured with Klippel SCN system.