Miniature loudspeaker

A loudspeaker, comprising:

• a housing, with an opening at the top to form an accommodating space;
• a magnetic circuit system disposed in the accommodating space, having a spacing from the housing to form a resonant cavity, and being provided with a first tuning hole communicating with the resonant cavity;
• a vibration system, disposed at the opening of the housing and comprising a diaphragm and a voice coil, the diaphragm being provided with a second tuning hole communicating with the outside;
• a damper, configured as a ring structure to form a third tuning hole, two ends of the spring wave being respectively connected to the magnetic circuit system and the diaphragm;
• and
• a control circuit, configured to input a direct-current bias current to the voice coil to adjust an initial position of the diaphragm;
• wherein the first tuning hole, the third tuning hole, and the second tuning hole cooperate to form a sound guiding channel, and the damper extends or shortens following the change of the initial position of the diaphragm to make different direct currents correspond to different lengths of the sound guiding channel.