I'm going to be building an enclosure for a friend here in the next couple of weeks for 4 10's. I drew out the layout of the box on a big piece of paper. The original plan was to have the 4 subs upfiring with the port facing back. However, 2 of the subs are really close to the port opening in the box. I'm just wondering if the subs being as close as they are, if it will affect the way the subs perform. I have an alternate plan to face 2 of the subs upfiring toward the middle of the top baffle, and have 2 rear firing on the same baffle as the port. I have drawn a simple sketchup of what it would look like in both situations so you kind of get an idea of what I'm talking about. Which route would be the best to go with? The setup will be going in the trunk of a Grand Am.

Original Plan:

http://i96.photobucket.com/albums/l199/playerskater28/topviewbox.png

Alternate Plan:

http://i96.photobucket.com/albums/l199/playerskater28/topviewbox2.png

http://i96.photobucket.com/albums/l199/playerskater28/frontviewbox.png

I think the alternate plan would be the better way to go. Having some subs away from the port opening, and others close to it can cause loading issues. You've probably seen it before when watching someone's multiple sub setup playing and seeing things like some subs barely moving and other's moving like crazy all in the same air space just as an example. I talk to a guy on another forum who has ran and is continuing to run into this issue. In his last setup he had four 12" DD9500's and the two closest to the port opening would always unload before the other two. He's got a big 4th order setup for four 15" Sundown SA's now and keeps having air leak issues with the back of the enclosure and the sub closest to the leak unloads before the others as well.

I think your alternate plan would do the best at keeping the subs evenly loaded. Then again, I've never had to fight that issue personally, so I could be wrong. BTW, if you want a nicer sketchup drawing to go by just PM me, I'll draw it up for you.