Smart Madness underdash sub

[Smart990]

Anyone with either the smart madness or 4smartcar underdash sub box using polyfil? Do you think this would be beneficial with the JL 8W3V3?

[Napoleon12]

if the box has the right spec's for the sub you are fine. poly will just trick the sub to think it is in a bigger box by slowing down the sound waves

[sato7]

they say as a rough estimate you should put a half pound of polyfill in for every cubic foot of air space.

[sato7]

UHHH thats inside the sub box not the airspace in the car!!!!!!