<https://www.diyaudio.com/community/threads/what-do-you-put-in-a-sealed-midrange-enclosure.287609/>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.diyaudio.com/community/threads/what-do-you-put-in-a-sealed-midrange-enclosure.287609/>