Can someone check my box design for me?

GaryPham · Post by **GaryPham** » Thu May 10, 2007 3:01 pm

Hi guys, I'm kinda new to this whole box design thing and was wondering if someone out there can run these specifications through their box design program or something to make sure that it's correct. This is a design for a single 12" Rockford T2.

Rockford recommends a net volume of 2.25 cubic feet after displacement. In my design here, the internal volume is about 2.591 cubic feet before sub displacement (0.151 cubic feet) and the displacement for the double baffle layer which I'm gonna add INSIDE the box behind the original front (0.14 cubic feet after removing the volume of the hole cut).

If my math is correct this should bring me to a net volume of about 2.3 cubic ft after all displacements. I'm also going to add a 45 degree corner to the back corner of the box which will probably bring the net volume down closer to the recommended 2.25 cubic feet.

This is the design I have for it as of now:
http://img2.freeimagehosting.net/uploads/ba9cf0ea14.jpg

According to the RE Calculator, the box is currently tuned to about 34.9 hz. Will this tuning frequency change after all the displacements? If so, about how much would it change? my target is to keep this box tuned at about 35. If someone could check these for me to tell me if my box is designed correctly I'll be much appreciative.

Thanks!

breakjunki · Post by **breakjunki** » Thu May 10, 2007 3:12 pm

you should be fine. in all honesty small changes like a brace in your size box won't affect your tuning significantly. I looked at your design, even with the bracing and dispacement you may only be a hz give or take off of 35. so pretty close...

breakjunki · Post by **breakjunki** » Thu May 10, 2007 3:35 pm

yup.. I feel better now.. just to make sure you stayed at about 35 I just played with the re calculator also. Your going to be a bit over 35 with the displacement

GaryPham · Post by **GaryPham** » Thu May 10, 2007 3:44 pm

hmm, so how would I know what frequency I should be at before displacement so that I can be at 35 after displacement?

GaryPham · Post by **GaryPham** » Thu May 10, 2007 4:35 pm

hmm ok I think I know how this works now. Can you take a look at this new design to see if it works?

http://img2.freeimagehosting.net/uploads/24d9c57b52.jpg

gross volume = 2.554 - sub displacement(0.151) - 2nd baffle (0.1343) = 2.269 cubic feet

From my new calculations, after this sub and baffle displacement is accounted for, the new frequency should rise to about 34.9 hz right?

breakjunki · Post by **breakjunki** » Thu May 10, 2007 6:01 pm

yup, you got it man.. the diplacement from the sub, baffle and bracing will make the tuning rise so you'd be right at 35ish.. I've always like anywhere from 30- 35 for my daily music setup..let us know how it turns out... good luck with the box building. I just built a 7.5 ft3 for my re 18 sx @33hz, that turned out to be a monster box