People make various efforts to maximize the perceived loudness of portable device speakers, but care must be taken to avoid damaging the speakers themselves. These small transducers can only withstand a limited volume. There are two main aspects of speaker protection: maximum diaphragm displacement and maximum voice coil temperature.

In a typical speaker cross-section diagram, the physical limits of diaphragm movement are clearly visible, especially in the downward direction. Audio signals must not be too strong, as this could cause the vibrating element to come into contact with the fixed basket assembly or result in excessive tension in the suspension material (ring or spring). Additionally, the RMS value of the audio signal must not be too high, as this could cause the voice coil to overheat. Voice coil overheating can cause circular deformation of the coil tube, leading to friction with the magnet or magnet pole piece edges. Furthermore, high temperatures within the voice coil can degrade its electrical insulation properties, ultimately causing short circuits in the voice coil windings, thereby reducing voice coil impedance and overloading the amplifier. Excessively high voice coil temperatures can also cause the permanent magnet to overheat, potentially leading to demagnetization.

Technologies used to prevent speaker damage include: automatic gain control (AGC) for input signal amplitude and/or power supply voltage, dynamic range compression (as mentioned earlier), hard limiting, soft clipping, and amplifier output overcurrent sensing. The drawback of these technologies is that they are all feedforward methods and cannot detect actual speaker cone displacement, voice coil temperature, or speaker impedance (which changes proportionally with temperature). More complex protection mechanisms, such as thermal feedback, are expected to be implemented in the future, but the current conventional methods involve one or more of the aforementioned protection mechanisms.