For the purposes of quantifying speaker sound quality, we rely on a lot of established research. Some of that research is pretty old and to advance the state of the art, it is useful to get outside of the box. Found this AudioXpress article interesting, so thought I would share...
https://audioxpress.com/article/sit...fferent-ways-of-thinking-about-speaker-design
https://audioxpress.com/article/sit...fferent-ways-of-thinking-about-speaker-design