A loudspeaker, also known as a “speaker,” is a widely used electroacoustic transducer found in virtually all electronic devices that produce sound. In audio equipment, the loudspeaker is the most vulnerable component, yet it is also the most critical for sound quality. Despite its simplicity, its development was not achieved overnight but through decades of research and the collective efforts of countless individuals, gradually evolving into the mature and advanced technology we have today. The invention of the speaker was aimed at achieving “faithful reproduction of the original sound.” However, despite the efforts of countless scientists, this goal has yet to be fully realized. Instead, different sound production methods, manufacturing techniques, and material applications have led to a diverse array of speakers, making them the most vibrant and brilliant segment of the audio world. Speakers are categorized into built-in speakers and external speakers. External speakers refer to the typical speaker cabinets, while internal speakers are those built into devices like MP4 players. There are many types of speakers, which can be categorized based on their transduction principles into electrodynamic (dynamic), electrostatic (capacitive), electromagnetic (reed), and piezoelectric (crystal) types, among others.