[why?]

Originally Posted by finch1750

If you look up the sub specs it should tell you what kind of volume you need and you can compare measurements that way.

You also might have better luck in the Audio subforum
https://www.ft86club.com/forums/forumdisplay.php?f=27

it's kind of slow, going to https://www.diymobileaudio.com/ is probably better.