Box design help!!!

[Strokerjoe]

So could I cut a square port that would slide into existing port on my box work?

[DLHgn]

Well, if you're just trying to adjust tuning you could always making something that bolted on the top of the box that had the exact same dimensions as your port (11.5 x 11.5) and has a specific length or something that bolts on that has an interchangeable pieces to adjust length. However, this only works if you want to try and go lower. Going higher would require you to either make the port area larger, shorten the port length or make the net volume smaller. All of which can be difficult to do.

[Strokerjoe]

Do you think if I flipped my box on its side and fire woofers and port towards rear it would hit harder? My only issue is that my box is narrow and I would have to figure out a way to anchor it down

[DLHgn]

I couldn't really tell you if it would hit harder because every vehicle and box is different however, I can tell you that in Home Audio, corner loading your sub (literally facing sub/port towards the corner with enough room to operate properly) can increase output of the sub in sacrifice for the sound quality (muddies up the sound and makes it more boomy). May be the same concept in a car cabin but I couldn't tell you for sure. I would say try it while you're parked somewhere and see if you like it. If so figure out a way to strap it down securely when you get home. Just make sure it's secure whenever you're driving. You don't want that thing loose in the event of an accident.