The voice coil of the bluetooth speaker is small in diameter and high in power, so the voice coil generally needs to use high-quality components to meet the requirements. In terms of sound cones, due to the high requirements for sound sensitivity and clear sound quality, but they are small-diameter speakers, most people use paper cones with natural sound, good rigidity, light material and high sensitivity. HiFi systems are made of paper cones. Abound, because the sound output is very average and the reproduction is good.