SSZTDE7 October   2026 TAS2573 , TAS2781

 

  1.   1
  2. 1 Introduction
  3. 2 The physics of microspeaker vulnerability
  4. 3 Traditional versus smart approaches to audio design
  5. 4 Integrated IV-sense circuitry
  6. 5 The temperature protection algorithm
  7. 6 Thermal modeling and control
  8. 7 The excursion protection algorithm
  9. 8 Look-ahead limiter
  10. 9 Integrating the audio tuning chain
  11. 10Conclusion
  12. 11About the authors
  13. 12Additional resources
  14. 13Trademarks

8 Look-ahead limiter

If a low-frequency bass transient (such as a snare drum hit or an explosion in a movie) threatens to push the cone past its Xmax, the excursion protection algorithm deploys rapid, targeted countermeasures. A brief digital delay buffer (typically a few milliseconds) enables the DSP to see a dangerous peak before it actually reaches the amplifier stage, giving the algorithm time to apply a precise, instantaneous peak attenuation to that specific waveform cycle. See Figure 8.


Closed-loop excursion protection

Figure 8 Closed-loop excursion protection

In Figure 9, the blue curve represents the smart amplifier’s estimated excursion, while the red lines indicate the Xmax limits. The amplifier dynamically modulates the audio to ensure that the speaker is always within reliable excursion limits.


Real-time excursion tracking relative to the Xmax limits

Figure 9 Real-time excursion tracking relative to the Xmax limits