Quote Originally Posted by beeza View Post
With the sub,flip the speaker over and screw it down upside down.Then switch the wires that run to the sub,i.e + to - and - to +.And make sure there a breather hole in the sub.
Inverting a sub will make no difference to a subs' sound. Newton's third law dictates this. The only possible difference is created by an increase in enclosure volume due to the motor structure and magnet no longer displacing volume within the enclosure (this difference will be negligible). Mounting inverted is for looks only (I'm not suggesting this is a bad thing, I had my sub mounted inverted for quite some time).

You can't just punch a hole in a random box... You need to properly tune a specified size sub box with a particular diameter and length port to achieve optimal performance.