Anyone interested in making money? Need a SPL box built for a Type R

[joem1cha3l 10+ year member]

Who needs money and is good with figures, i need a box built for SPL for my Type R. It needs to fit in the back of a BMW 3 series, can get measurements....lmk guys. Price is negotiable.

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[bikinpunk 10+ year member]

Just spotted this and figured I'd give you the same info I did for someone else. This is for a 10"...dunno if that's what you have or not, but if not, no loss. This is a copy & paste from another post I made. The advice was to help it act more as an SQL box...

With the size restrictions it’s very hard to make a box with a flat response (which I’m very keen on). For SQ purposes you want a flat response.
The best I could come up with is below.

It’s 1.5 cubic feet, and tuned to 36hz. Tuning any lower than this would make the port too long and would run into the subwoofer, depending on placement of the port & subwoofer. You can get around this issue, and I have listed a couple ways below. Oh, this was designed with a 4” circle port. Here’s a link to the circle Port. It’s the same one I used.

You can buy Polyfill from wal-mart, stuff the box with that, and your peak should be brought down. You can add a little bit at a time until you achieve your desired results.

You have 3 choices with how you do the port:

1. I personally bought the one linked above mainly because the flared end allows has screw holes making it easy to screw into the box from the outside. I wound up going to Lowe’s and getting the thin-walled PVC so I can make the port longer, and grinding down the ends and fit the flared port ends on them. The flares keep from getting port noise.

2. Or, just go to lowe’s, buy 4” THIN-WALLED PVC pipe (it’s the same, just thinner wall, hence the name) and cut to the size you need.

3. You can always have an elbow port. This means just go to HD or Lowe’s and buy an “elbow” for PVC pipe, and that should allow you squeeze a couple extra inches of port, thus bringing the tuning frequency down a bit and flattening out your response.

It’s up to you. Just know that however long you make the port, it needs to be a couple inches away from the subwoofer.

Now, I think you can see why I chose a circle design.

This really is straight-forward, regardless of how confusing I have just made it:

1. Build a regular ol’ box with dimensions I give you.

2. Cut speaker hole.

3. Mount speaker.

4. Now you can play with port length.

Design Response (see what I mean about the peak near 40hz? I don’t like it, but I can’t do much about it unless I get a bigger box)

External Dimensions:

Length 20.00

Depth 13.50

Height 12.50

Use 3/4" MDF