View Full Version : I need help tuning a box.

04-13-2010, 07:44 PM
I'm building a box to fit inside a grand marquis. its going to have 6 12" RE REX12D4's in it. each sub has a .1 Cu.Ft displacement and an Xmax of 12mm (if that even matters). the box is right now 8.02 Cu.Ft. (40w x 26d x 17.5h with it indenting a little towards where the front is) and i need it tuned to 35Hz. Anyone mind helping me out? i have a cardboard port that's 4 inches in diameter that i can cut to any length, but i want it to stay inside the box (if it has to stick out a couple of inches I'm fine with that too).http://c2.ac-images.myspacecdn.com/images02/67/l_dae3717f36e5431f947ac05ee0f29de5.jpg

04-13-2010, 08:01 PM
Sorry bud, you are gonna be bummed. You need like (10) 4" ports to get enough port area for that box. You can get away with 2 8"ers if you can find the material but it will need to be like 22" long and that is still light on port area for that many cubes.... Basically you need 122 SqIn of port to support that many cubes, or it will sound crumby... You could always do a removable slot to the front and port through the back seat! YEAH!

11X11X24" long bolt in port through the rear seat baby!! FTW!


04-13-2010, 09:28 PM
Thanks man. the port that i have is over 8 ft long and u said i needed it to be 22". so if i cut two ports to be 11" long would that be good? Thanks for the reply

04-13-2010, 10:26 PM
I don't think you read my post correctly, You need a MINIMUM of 2 8" DIAMETER ports 22" long or you will be throwing a TON of sound out the window and the big bad 6 12 box will sound like a single 10 in a good box...

04-14-2010, 01:21 AM
oh alright man. thanks. what about two Square ports 6"x6" ?

04-14-2010, 10:28 AM
Well that would be closer, if you did that and routered the edges of the port all the way around inside and out so its all rounded, you might be OK. I would call that the absolute minimum. You might still get a bit of port noise though You will need to make them each about 15" long to get the tuning you need. Post pics when you are done I would like to see it all done!

04-16-2010, 01:23 AM
most definitely will put some pics up. i will end up doing a different port on the side of the box too that will have 2 Cubes of port and bring the inside volume to about 8.3 Cubes.

04-16-2010, 10:21 AM
OK, so you are doing an external port then? Sounds like a better plan....Should sound good!

04-16-2010, 07:28 PM
yep. i went and re-measured his trunk, ( and asked him if he'd be ok with the port through the back seat, he said no though :-/ ) and i figured i could put up to 3 extra inches on the side and 5 on the bottom so this is what i decided to do. http://c3.ac-images.myspacecdn.com/images02/114/l_f6bc5262a019491cb797d8ca1e360fee.jpg

04-17-2010, 03:41 PM
This is what i got so far,(top still needs to be put on).