Loudspeakers are devices that accumulate heat during their transduction process. The rise of temperature is potentially harmful for the voice-coil and must be countered by the active heat control (AHC) process when other passive and mechanical dissipation schemes become inefficient. Known AHC aim at limiting the voice-coil temperature through a closed-loop approach and may lead to oscillations and audio artifacts when temperature measurements are available with latency. This paper establishes that an open-loop AHC relying on a dynamic range compressor configured as a brick-wall limiter whose threshold is modulated by the temperature of the magnetic components insures a bounded voice-coil temperature. The temperature of the magnetic assembly and the driving force of the loudspeaker can be both estimated in real-time, respectively by a linear quadratic observer (a Kalman filter) and by an envelope follower. The new AHC scheme is demonstrated and compared to closed-loop AHC on a simulation example.
(See document for exact affiliation information.)
Click to purchase paper as a non-member or login as an AES member. If your company or school subscribes to the E-Library then switch to the institutional version. If you are not an AES member Join the AES. If you need to check your member status, login to the Member Portal.
