Broadband speaker and control method thereof

A method of controlling a broadband speaker, which comprises:

• a first vibration plate configured to operate in a high frequency band;
• a second vibration plate disposed outside the first vibration plate and configured to vibrate in a lower frequency band than the first vibration plate;
• a first voice coil connected to the first vibration plate to vibrate the first vibration plate;
• a second voice coil disposed outside the first voice coil and connected to the second vibration plate to vibrate the second vibration plate;
• a magnet assembly configured to form a magnetic field for operations of the first voice coil and the second voice coil, respectively;
• an amplifier configured to apply a first output signal of a high frequency band to the first voice coil and a second output signal of a frequency band that is lower than that of the first output signal to the second voice coil;
• and a controller configured to control the amplifier to apply a signal for suppressing vibration of the second vibration plate to the second voice coil when the first output signal is applied to the first voice coil;
• the method comprising:
• determining, by the controller, whether the first output signal is applied to the first voice coil;
• measuring, by the controller, a current generated in the second voice coil upon determining that the first output signal is applied to the first voice coil;
• and
• controlling, by the controller, the amplifier to apply a reverse phase signal of the first output signal to the second voice coil.

A method of controlling a broadband speaker which comprises:

• a first vibration plate configured to operate in a high frequency band;
• a second vibration plate disposed outside the first vibration plate and configured to vibrate in a lower frequency band than the first vibration plate;
• a first voice coil connected to the first vibration plate to vibrate the first vibration plate;
• a second voice coil disposed outside the first voice coil and connected to the second vibration plate to vibrate the second vibration plate;
• a magnet assembly configured to form a magnetic field for operations of the first voice coil and the second voice coil, respectively;
• an amplifier configured to apply a first output signal of a high frequency band to the first voice coil and a second output signal of a frequency band that is lower than that of the first output signal to the second voice coil;
• and a controller configured to control the amplifier to apply a signal for suppressing vibration of the second vibration plate to the second voice coil when the first output signal is applied to the first voice coil, the method comprising:
• determining, by the controller, whether the first output signal is a frequency corresponding to a multiple of a natural frequency of the second vibration plate;
• and
• applying, by the amplifier, a reverse phase signal of the first output signal to the second voice coil upon determining that the first output signal is a frequency corresponding to a multiple of the natural frequency of the second vibration plate.