Box help again

[bbeljefe]

That's all correct except that your port is going to occupy 1.82 cubic feet and the drivers will probably displace ~.28 cubes, for a net of 7.9 cubes and tuning of 44 Hz.

[robby512]

Alright!

Well my thought is that I got the math right and how to figure out then add in the port displacement onto it so my box will about 11.82 cubes Won't that work and still get me 10 net cubes and a tune of 35 hz?

[bbeljefe]

Don't forget to add the sub displacement too, but yeah, that's right. I thought you meant you only had ten feet to work with, which was confusing to me because I've got ~18 feet in the rear of my cab... under the window.

So get to building! :-)

[robby512]

Yea below window I got about same 18 cubes and unfortenaly build won't start till Wednesday but I'll be able to hopefully perfect my idea by then. Thanks again for your help and I appreciate you not being a douche and taking time to answere the same question I asked 5 times. And I feel I have a decent idea on how to now and hopefully can pass on this info to help someone else.

[bbeljefe]

My pleasure man and thanks for not flaming me when I fucked up. I'm here to share ideas and learn while I'm at it and any time I can do both, it's a good day.

And do post up some build pics. I'll be doing the same, and as it's looking, I probably won't get started on mine until Tuesday with this console to finish first.... and I gotta have it done by next weekend so it's gonna be hectic.

[robby512]

Yea one I'm in no position cause I didn't know different and two no one is perfect and we got it done right in the end and thats all that matters. Yea I'll have to when I get to it now I'm running into confusion I understand how to get cubic feet but not sure how you got that number the port is going to occupy 1.82 cubes Im assuming that you take the l x w x h of the port but I come up with. 12 down and 6 over ( or should it be 5.25 because with 12 down 5.25 + the little .75 wood it connects to it would be 18 exact)

One will be 12 x 18 x 8 = 1728

6.75 x 8 x 18 =972

2700/1728=1.56?

I'm assuming my measurements are wrong

[bbeljefe]

Don't think about the L in the port. You need a port that's 8 x 20 x 18. The outside dimension of that port will be 8.75 x 20 x 18, which is 1.82 cubes.

The L will only about .03 cubes to the volume and that won't be significant, but you can add that to the total if you like.

[robby512]

Oh I see now that makes sense but my port I got that right correct? The 12 down and I need to leave 8 inch eide all the way around on the port even on the bend so 12 down and 5.25 over correct

[bbeljefe]

Yep... that's correct. And also, you should add a 45 in the outside of the port corner that will cut down on turbulence in the corner.

Just measure from the turn in the port across the turn at a 45° angle to the corner and cut the filler piece so that it maintains the 8" width in the corner.

Here's an example:

[robby512]

Ok things keep popping into my head and I'm like oh what about this.... My next one is bracing how much will 2 crosses inside the box cover enough bracing? Or should I be doing more?

I need to increase the width to 20 or more so I can get good bracing so that won't do anything other than make the port displacment a little larger I won't need to redo the port or anything cause port area is height times width of port opening correct?