轉載：科學角度看音響1：先了解聲音，再認識音樂，最後挑音響

音響中的高頻、中頻和低頻
https://www.techbang.com/posts/15882-scientific-perspective-sound-1-to-understand-the-voice-recognition-of-music-finally-picked-a-sound-system?page=3