Does it matter how you get your volume? for instance would an 'L' shaped box be any worse then a 'cube' shaped box? I know as far as sound waves are concerned that the ultimate shape would be a sphere but would i notice any considerable loss in sq or spl. I have an idea of an L shaped box with a thin channel in order to obtain the recommended interior volume.

Thanks in advance

 

here is a quick visual of what i am talking about:

 

Shape doesn't really matter. With the exception of the cube box you were talking about. If all the sides are exactly the same length, it is possible that the sound waves could actually hit the sides, top, and back at the same time, reflect back, and cancel each other out. It is generally NOT recommended to build a box in a square.

The diagram of the box you have will work just fine. Its a similar style to what you might see in the back of an extended cab pickup truck.

 

OH THAT'S RIGHT! thanks, i'm not sure if i'm going to do it yet, still trying to figure out the best looking install for my application

 

Does this box look similar?



Actually, this is one of the prototype subwoofer boxes for the C4 storage compartment that Subthump will be selling to C4 owners. This is, of course a rough design, not carpeted, not put together yet quite completely, but at least this show's we're dong something Finally, c4 owners will just be able to buy a drop in box. I still have to add a bunch of stuff and do a final acad drawing, but this is the basics.

snoopdan

 

snoopdan what kind of volume does the box have?
what size sub can fit?

 

My eyes are deceiving me, that box looks HUGE

 

NO, your right, its just the picture. There are really going to be 2 versions, one that fits up snug under the door carpet flaps, and one that extends up from the floor about 9". For this explanation, lets call them Box A, and Box B.

Box A is 32" x 14" x 1/2" (for the cover plate), and vaguely 10" x 8" x 12" for the recessed storage compartment enclosure. It comes in 8" and 10" driver size. This box is about .5 in displacement. Good enough for an 8 definately, kind of anemic for a 10" driver. This may change a little before its all said and done, and overall volume is going to be closer to .75 cubic feet. It can be installed without having to cut off the scissor jack mount, and leaves space around it for brownbread or dynamat insulation, or whatever you like to use. It sits a bit funny in the back of the car, and when the carpet is layed back down, it raises the floor height by 1/2". to make it look right, you will have to buy a piece of wood, and cut it to be around 32"x 20" to bring the floor back up to level. We figured that at LEAST a vette owner who is doing all of this DIY should be able to go to Lowes and have a peice of 1/2" wood cut for this. Its not that complicated.
Here is a pic of the storage box enclosure, just so you all get an idea of what you will be buying, when these become available. Remember, this is a Prototype, and sort of ugly right now. Some carpet and paint would go a long way at this point. But I wanted to all to see what ive been up to.



Box B is exactly like Box A in its design, except it will raise higher than the floor, and be around 9" in total heigth, spanning between the inner fender wells of the back of the car. This box, will of course not fit convertables. I dont have a convertable vette anymore, so I cant try out the box. If anyone lives in the Lousiville / Elizabethtown / Corydon, IN or west Kentucky and has a convertable C4 vette, id love to try out my box in your ride. But until that day, it will NOT be for convertable C4's. This box will have an air space of around 2.2 cubic feet. Enough for two 12" easily.


Both boxes will be sealed from Subthump, and if your particular subwoofer application needs to be ported, BUY A HOLE SAW BIT, and some PVC piping

Ive been also been toying around with a single 12" folded horn box, but I dunno on how much demand there would be for it.


any suggestions? comments?? Greatly appreciated.

snoopdan

 

have you ever tried to coat the interior of the box with fiberglass resin? a custom car audio guy who does that let me listen to his stereo and i was impressed with the sound. then he opened the hatch and showed me that it was the cheapest 8" woofer that eclipse had made (5 years ago) and i was floored.

 

Yeah ive done so much as add fiber mat to the resin as well, on a sealed box. Most of the time though, Its pretty hard to decompress a 1/2" MDF enclosure enough to where it matters if you put resin on the inside. Only reason I can see that being done, is a large driver such as a Tumult 15" sub (my dream speaker). If I was to put it into a sealed box, id probably go thru the effort of resining the inside of the box. But it doesnt help with sound quality any. Just good for keeping out the leaks, or for bracing if your box has a weird shape and you couldnt put bracing on the inside of the box for some reason.

A little acousta stuf / pollyfill is great for reducing standing and canceling waves in a sub box. Of course, I dont need to tell you all that. I think this C4 stealth box would be great with a JL W7 8" sub. It would have no problem fitting in it. And thru all my 8" driver research, the JL 8" (heavy eight) sub is the meanist on the block.


snoopdan