Heating voice coils raises resistance and lowers transducer output

Evidence

Power compression is a phenomenon that is related to high sound levels, but is not a non-linear distortion—it is a slowly varying linear distortion. As the voice coils of transducers heat up, their resistance increases and sound level output drops. It is not a very large amplitude change, but it can affect large portions of the frequency range. As the average power output increases, one can measure changes in the frequency response, often sagging output in the tweeter frequency range. — Toole, Floyd E, Sound reproduction- the acoustics and…, 1000

Categorization

• DEFINE: Drawing the precise distinction between power compression (a slowly varying linear distortion from coil heating) and non-linear distortion at excursion limits.
• corroborated: 2 independent passages support this claim — Toole, Floyd E, Sound reproduction- the acoustics and…, 1000