Loudspeaker Diaphragm Displacement Measurement Using a Laser

Laser Displacement Measurement final screenshotThis pre-written test sequence demonstrates how to use a laser and SoundCheck to measure the peak (max and min) displacement of a loudspeaker diaphragm. SoundCheck is easily configured to include a laser signal path, making it simple to correlate diaphragm displacement with electrical impedance and audio artifacts.

In this laser displacement measurement, the user is prompted to enter parameters including test level, start and stop Frequency and stimulus frequency resolution. The sequence then plays the Start Frequency through the DUT and records the resulting diaphragm motion with the laser. Post-processing functions create maximum and minimum curves across the frequency range and display them on a graph.