Aluminum panels on sealed MDF enclosure

[superdan50]

I recently designed an enclosure that lets me mount my 10" type R between the rear seats. I designed it on sketchup.



I was foolish and didn't take the time to model the sub to make sure everything fit correctly. now ran into some issues.

The space between the seats is 10", so the face that the sub mounts to is 10" across. once the sides of the extension are in place i loose 1.5", so my mounting diameter is down to 8.5" and i need 9.1". Additionally i fear that the structure of the extension won't be strong enough to support the weight of the sub.

So my solution so far has been to replace the sides and bottom of the extension with 1/8" aluminum. aluminum panels will be fastened to the mdf face and top. flush with the face and extend into the main volume structure and 90 degree on the backside of the main (structure) face. I figure the vertical aluminum panels would be plenty strong to support the sub woofer, and at a fraction of the thickness. and the mounting method (90 degree) will distribute the load across a large area.

I plan to throw some deadening on the inside of the panels to reduce vibrations, additionally the seats pressing against them on the outside to further reduce vibration.

has anyone used small aluminum (or any metal) panels in a box? im wondering if it will sound strange. I figured the hard surface of the aluminum isnt any different than that of a FG of plexi enclosure. also i am hoping the deadening and small panels will prevent any weird resonance.

Also the extension is pretty tight around the sub, will this be an issue?

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[jrdnhsnbrg 10+ year member]

Just throw a pair of 8s in there, problem solved

 

[superdan50]

I already own the 10s. i bought them years back and hadnt used them once. additionally i dont think you would get more than one in there. the pass through isnt high enough for a stacked setup.

 

[supra1987]

If measurements are good,cuts are good and box is solid it should sound fine.worst case maybe fiberglass interior of box to seal and reinforce seams.

 

[superdan50]

the aluminum is more due to size constraints than strength. though the strength of the aluminum over MDF is a nice bonus.

Any idea if it will sound weird?

 

[jrdnhsnbrg 10+ year member]

What kind of airspace is that?

 

[superdan50]

its a bit more than .65Cu Ft. according to alpines site .65 is optimum

 

[mlstrass 5,000+ posts]

why wouldn't you glue MDF pieces to each side to make it 10" wide? Kinda lost on why you want to do alum...

 

[vaiboy 10+ year member]

Have you considered downfiring the sub, it looks like it might be an easier solution?

 

[superdan50]

why wouldn't you glue MDF pieces to each side to make it 10" wide? Kinda lost on why you want to do alum...

the distance between the 2 vertical MDF pieces is 8.5". and i need a mounting hole of 9.1", so the aluminum is a lot less thick, and stronger. so it will give me the space i need to mount it and the strength to hole the sub.

Have you considered downfiring the sub, it looks like it might be an easier solution?

Is that when it is pointed in to the sub box and the basket out? my plan is to replace a cover that i will cut a hole in and throw some mesh over the hole. i want it to appear stock.

 

[vaiboy 10+ year member]

Is that when it is pointed in to the sub box and the basket out? my plan is to replace a cover that i will cut a hole in and throw some mesh over the hole. i want it to appear stock.

It's when the sub is mounted to the bottom of the box aimed at the floor.

Just looking at your drawing, with the sub mounted that high in a wedge box, it appears you may also have a problem with the magnet hitting the rear of the box.

 

[superdan50]

it shouldn't hit, though its close i drew the sub in sketchup as well. the circle on the face, is actually the face of the sub. if i were to rotate the drawing you could see the basket and magnet structure.



the red is the edge of the back, so you can see how close it is to the back panel.



the whole point for this setup is to allow me to have a sub between the rear seats. though i want it to be believable as stock.

 

[superdan50]

so my question remains unanswered, will the aluminum cause issues with the sound quality?