Method for improvement of loudspeaker properties - applies to natural and lower frequency ranges

摘要

The response characteristic of a loudspeaker is improved if it has a rapid acceleration. Improvement is achieved by movement negative feed back, and frequency correction is realised by positive feed back. A signal proportional to the coil current is positively fed back through a low pass filter, whose cut-off frequency lies in the oscillator natural frequency range ((+-) 1 octave). The lower cut off frequency of the power amplifier ensures a high-pass filter characteristic with a steep flank, suppressing very low frequencies outside the required range. The system also minimises parasitic oscillations.