Is this C4 front box design worth trying?

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Jun 26, 2002 | 06:42 PM

ToniH

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Is this C4 front box design worth trying?

Hi,

We had a conversation about C4 front speakers on the General -section but I received no comments about this design. How about here among the experienced? :D

The main point of this design is that there is no back wall but the recess in the sill is used as a back wall for the speaker box, gaining little more volume. Also this box design might be easier to make because I don't need to shape the back of the box to suit the recess.

Note that this is just a quick sketch so the shape of the box itself is just something to give you the general idea of what i'm thinking. And my text in the picture has error in it, I say that "without bottom wall" but I mean there is no rear wall of course. A link to the sketch

Please comment if this might work or not. :confused:

Thanks,

ToniH

[Modified by ToniH, 12:44 AM 6/27/2002]

Jun 26, 2002 | 09:16 PM

92TripleBlack

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From: Windermere FL

Re: Is this C4 front box design worth trying? (ToniH)

I've been having problems with posting pictures. My boxes came out from the frame rail using the angles of the indentation. They come through the frame rail cover, and extend past the cover by about 4 CM. I then made the tops of the boxes larger to cover the same area the stock speaker grills covered. Looks stock but intrudes a little more into the legroom, maybe by 2 cm more, and fits a 6 1/2" speaker in a sealed box easily. I'll post them as soon as I can get the problem resolved with the forum people.

Jun 27, 2002 | 01:13 PM

ToniH

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Re: Is this C4 front box design worth trying? (92TripleBlack)

Hi,

92TripleBlack, here are your pictures. Thanks for posting them to me!

Front angle picture
3-view picture

Very nice drawings, very clear but looks little complicated to make? I think there is no more designs around, is there? It must be one or the other of these then...I do have the tools and now also enough MDF to do the boxes, I just hope my skills are good enough ;)

ToniH

[Modified by ToniH, 7:24 PM 6/27/2002]

Jun 27, 2002 | 02:56 PM

92TripleBlack

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From: Windermere FL

Re: Is this C4 front box design worth trying? (ToniH)

I used a jigsaw or reciprocating saw, circular saw, drill, holesaw for the drill, belt sander, and glue to make these. The tools weren't that much. Each side I first made the pocket, then the front, then the side piece, finally the top. Then I added a second front panel so the speaker would be recessed and flush with the front of the box. Last, I trimmed the edges at an angle with the circular saw and then sanded them all round with the belt sander so its smooth and there are no sharp edges. Most people, even some corvette owners, don't notice them even when I tell them to look at them until I actually say, I made this thing and touch them.

Jun 27, 2002 | 03:38 PM

R23HTC

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From: Little Elm TX

Re: Is this C4 front box design worth trying? (92TripleBlack)

Those look good. I have a few more ideas now anyway. I might go back in once I get the car back and mess with it some more. Toni gave me an idea when he said something about sealing a flat piece to the sill recess. I might work off of that.

Jun 27, 2002 | 03:42 PM

92TripleBlack

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From: Windermere FL

Re: Is this C4 front box design worth trying? (R94 LT 1)

I thought about that. It would give you max volume but it would be difficult to keep a seal The best would be to make the boxes, attach them with L brackets to the frame rail, and then seal them. But this would make removeing them and the frame rail covers a nightmare also. My boxes are held in with a single 1 1/2" screw in the back of the box and friction. Just remove the midrange and unscrew the screw and they pop out when needed.

Jun 27, 2002 | 03:48 PM

R23HTC

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From: Little Elm TX

Re: Is this C4 front box design worth trying? (92TripleBlack)

I haven't taken it back apart to look, but try this theory.

If you can get a piece of MDF to lie flat over the recess with a decent amount of overlap, then cut a hole in it to match the recess. Use a foam type weather strip material to outline the recess. You could stick this on the sill around the recess. Then your flat piece would lay on top, virtually sealing it there, and could be screwed down to the original locations. Then you could build up from the flat piece, similiar to what 92TripleBlack did, or whatever suits you. Anything built up from the flat piece would be glued and sealed to it, leaving more volume in the rear because there's no wood back there. Is this theory viable?

[Modified by R94 LT 1, 1:49 PM 6/27/2002]

Jun 27, 2002 | 04:37 PM

ToniH

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Re: Is this C4 front box design worth trying? (R94 LT 1)

> I haven't taken it back apart to look, but try this theory.

This is exactly what i was thinking. If you think it is difficult to use a thick enough piece of mdf (rigid enough for good seal) you can always use thinner mdf and laminate (ie. glue) a sheet of thin aluminium to the mdf board. This will stiffen it up considerably.

This is what is done when building an experimental aircraft you want a stiff board which is both thin and light: combine wood and metal :D

If I remember it correctly the recess on the sill has a "leak" in the lower part. Ie. just a flat sheet of mdf will not seal without first filling this. I think it was like 1-2" long so it should be easy. After that I think the theory is sound.

Toni