Driver Distortion, Compression, Rub, Buzz, And Defect Testing

A smooth low-level response does not prove clean operating-level behaviour.

Name the measurement

harmonic distortion
intermodulation or modulation distortion
fundamental compression
rub and buzz or impulsive defect energy
mechanical noise
thermal or displacement state change

Verify the chain first

Confirm source, amplifier, microphone, analyzer, ADC, and fixture headroom. If any upstream or measurement stage clips, the driver cannot be assigned the result.

Progress level deliberately

Use declared terminal-voltage steps, ramp, duty cycle, rest, and stop limits. Record the first level where compression, abnormal noise, or a defect appears rather than driving onward for a larger graph.

Isolate the mechanism

Repeat after changing fixture, gasket, grille, lead position, orientation, microphone position, room, and driver sample. A test-baffle buzz can resemble a driver rub.

Preserve state

Record DC resistance, temperature, fundamental level, distortion components, compression, displacement, and the exact signal. Averaging and smoothing can hide intermittent defects.