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View Full Version : Sub box Port Question + my new Sub Plans


ScienceVR6
22-05-2007, 09:37 PM
Im in the process of building a 120L Sub box, to take 1 15" Rockford fosgate "P1" Sub, and i plan to use a Slot port design. has anyone had any expeariance with these? Iv'e never built one, and would like to know how others tackled the project.

Im chasing SPL, but i would'nt mind a bit of clarity. The original plan was for 2 cheaper 15" subs in a seald box, but after running into trouble with clearance issues, and un-availibility of the subs i wanted, iv'e decided to go this way.

The top of the box will form the parcel shelf, and will be trimed in the same carpet, the sub will tilt away from the window, on the top of the box, so as to look inconspicuase through the rear window (dont worrie, its tinted) and the box top will be extended to meet the rear window, just like the parcelshelf does. The size of the box, combinde with the slot port should equal a bloody loud bass note.

Best of all, I COMPLETELY LOSE MY BOOT!
http://www.vwwatercooled.com.au/forums/images/imported/2007/05/SUbincar-3.jpg
MattyT
22-05-2007, 09:41 PM
Thats a freaking big box.

See http://www.mobileelectronics.com.au/forums for plenty of good advice on box building. I know nothing about em personally. Dont even own subs!
joshyd-mk2gti
22-05-2007, 11:17 PM
youd be better off facing it towards the back of the car, or tilted up at the back window slightly. theres a bit of physics involved, but basically the bass wavelength takes a long distance to mature. the lower the hz the longer (in metres) it takes to mature. so yeh, face it to the back and the distance is increased.

what amp you got?
BlackVr6ix
23-05-2007, 08:58 AM
^^^ you get cabin gain of between 3-5DB by firing the sub off the back window.

in my old alfa there was a 7 db difference in the way i placed my subs!
ScienceVR6
23-05-2007, 06:38 PM
youd be better off facing it towards the back of the car, or tilted up at the back window slightly. theres a bit of physics involved, but basically the bass wavelength takes a long distance to mature. the lower the hz the longer (in metres) it takes to mature. so yeh, face it to the back and the distance is increased.

what amp you got?


^^^ you get cabin gain of between 3-5DB by firing the sub off the back window.

in my old alfa there was a 7 db difference in the way i placed my subs!


Ive run into some trobles, and it will now be facing the window, with the ports blowing into the (remaining) boot space.

The amp im using is a Directed Extream 1500X mono, its a bit small, but it does a very good job.
joshyd-mk2gti
23-05-2007, 07:58 PM
even if its only a few inches from the hatch, i think it would be better with the sub facing directly back, not angled up. rule of thumb, put the port on the baffle (the same plane as the sub).

try get some better gear, make a big improvement.. even those jaycar mono's are good bang for buck. check the for sale section on CAA (mobileelectronics), always some bargains popping up.