6 15's, blowthrough on 2k. Mid 50's? MTA read this.
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I agree with MTA - the loading on that box is all over the place.
With 49" width I would think hard about 3 x 15" straight across or 4 x 12" on a V baffle.
And until you know how much air you have in the front of the box, and how big a blowthrough you are going to cut, you can't figure how much effect it will have.
With 49" width I would think hard about 3 x 15" straight across or 4 x 12" on a V baffle.
And until you know how much air you have in the front of the box, and how big a blowthrough you are going to cut, you can't figure how much effect it will have.
Audio Innovations (of Florida, I think) made that box.
It's a port firing into a bigger space that's firing into another bigger space (the cab) so it's technically not a 4th order BP because there is nothing sealed, although it seems like a wack 6th order. Maybe he calculated it to what he wanted - it metered 155 @ 32 with 10k. Major cancellation issues. I think he should have upfired them and used lots of deadening on the cover. It's a waste of space, he could have used 8 15's with a normal port but he just had to duck down and see them from the cab. I say who cares, if you want to see the subs than open up the bed cover and drool!
Before the wheel wells - 62w x 18h x 35d, with 1" MDF = 18.33333 cf3.
How is the wheel well to the back of the box 49" wide when it's 62" in the front? It's not angled, right?
You can fit 2 18's on an angled baffle in 14-16 cubes, everything firing into the cab. Use whatever angle that lets you keep 1" of space between the inner sub cut-out and the outer MDF, in your case you'd need 20.75" to fit into 18" (16.75" inner sub cut out + 4"), which is an angle of 60.15 degrees.
Side A 18, side B 10.33, side C = 20.75
Right Triangle Angle And Side Calculator
You have enough space to properly use a 20.5" port (leaving 1" between the sub inner cut-out and the wall), x 16 = 328 port area, which is more than enough. If the port was a square 16 x 16, calculated to 20" long, in 16 cubes, it's very close to 35hz, with 16 square inches of port per cube. A calculator says two BTL 18's need about 300 square inches of port @ 35hz, and 2/3 is needed for something like a DD 9500 (if the x-max is 18mm)...
edit: I didn't angle the top view.
It's a port firing into a bigger space that's firing into another bigger space (the cab) so it's technically not a 4th order BP because there is nothing sealed, although it seems like a wack 6th order. Maybe he calculated it to what he wanted - it metered 155 @ 32 with 10k. Major cancellation issues. I think he should have upfired them and used lots of deadening on the cover. It's a waste of space, he could have used 8 15's with a normal port but he just had to duck down and see them from the cab. I say who cares, if you want to see the subs than open up the bed cover and drool!
Before the wheel wells - 62w x 18h x 35d, with 1" MDF = 18.33333 cf3.
How is the wheel well to the back of the box 49" wide when it's 62" in the front? It's not angled, right?
You can fit 2 18's on an angled baffle in 14-16 cubes, everything firing into the cab. Use whatever angle that lets you keep 1" of space between the inner sub cut-out and the outer MDF, in your case you'd need 20.75" to fit into 18" (16.75" inner sub cut out + 4"), which is an angle of 60.15 degrees.
Side A 18, side B 10.33, side C = 20.75
Right Triangle Angle And Side Calculator
You have enough space to properly use a 20.5" port (leaving 1" between the sub inner cut-out and the wall), x 16 = 328 port area, which is more than enough. If the port was a square 16 x 16, calculated to 20" long, in 16 cubes, it's very close to 35hz, with 16 square inches of port per cube. A calculator says two BTL 18's need about 300 square inches of port @ 35hz, and 2/3 is needed for something like a DD 9500 (if the x-max is 18mm)...
edit: I didn't angle the top view.
Last edited by Lord Huggington; Aug 14, 2010 at 03:54 PM.
