PennState

hey i had a huge box in the trunk of my car, it went in with some wiggling but took a lot to get it out..

luckydawg003

Well I just remeasured were I want the box to go. I don't think it will give me the volume I need for the subs. Both subs together need a minimum air space of 1.6 In. Max 6 In. The rear of the box can't be more than 12 In. in height. and the front of the box can only be like 13-16 In. high, because of this square metal brace on the rear roof of my car. Also I have to cut the weird upward angle into the bottom of the box. The angle is 9 In. from the start of the hump to were it levels out flat. The flat part to the rear seat is 7 In. This is going to be the most confusing weirdest shaped box ever. How do I figure out the interior volume with all the angles of my box?

seight311

That post made the least sense.

Really. Do not build a box. Buy one, live with a pre-built 1/4 particle board... thing. Your seriously going to cut your neighbor three houses down's arm off. How do you calculate a box... seriously, how do you breath. Google douche, live it, love it, learn it. If you would have read anything anyone has said in this topic, let alone either of the FAQ stickies, you could have figured out, bulit a box, been jamming, and not given up your status as a complete tool by now. I am so suprised you can honestlytype at this point, so surprise me and build something that doesn't resemble a Van Gogh piece.

Oh why yes, I am being an ***. Enjoy, your 17 and you really will blow something up. Too bad you weren't half way intelligent and atleast listened to a fraction of the things I had to say. I see ttocs has been up and down with you. Good luck.

ttocs

volume is found with the formula L x W x H. This is more difficult when you are dealing with a complex shape so to make it easier then break itdown intoa couple of different shapes and then find the collective volume of those shapes. Find the volume for the largest rectangular shaped piece first. For the remaining triangle shaped pieces, take the bottom measurement and then move that to the top. Find the volume for the new rectangle(L x W x H again) and then cut in half to find the volume of the triangle, and now add that to the first measurement.

Not to insult you but if you are still in school this is a good real world problem that one of your math teachers could turn into a great lesson, while solving your problem. You both win.

luckydawg003

Ok heres the dimensions I want to work with. Front of box 12" in height 34" wide, Top of box 8" deep, Rear of box 12" tall, bottom flat part 7", Bottom angled part 9". This should give me about a 1.6 int. volume, and will fit exactly were I want it to.

ttocs

are you using the internal measurements of thebox or the external measurements? It is critical to use internal measurements to calculate the volume, don't forget to subtract the displacement of the motor. The internal measurement will vary depending on what thickness of wood you use. 3/4"mdf is the standard and if you do this the internal measurements will be off by 1.5" on a couple of the measurements.

luckydawg003

Those are the boxes external dimensions. I am going to be using 3/4 mdf. Not sure about the subs magnet size.

ttocs

ok so you will need to re-calculate and figure out how to add more space to it. The external dimentions of the box will include the volume that the wood takes up. With the wood as well as the motor/magnet taking up the volume that you calculated the box will be too small and you will not get much out of the speaker. The length of the box as well as the height cannot be adjusted, so you need to add to the depth of the box.

The volume of the magnet is included in the spec sheet for the speaker, or online at their website.

Emanpimpster

Ok sounds like you never took a damn geometry class in highschool so this should be helpful http://www.bcae1.com/spboxnew2.htm
about 3/4 of the way down the page theres a calculator that will help you with weird shaped boxes. You can type it the thickness of your wood and play around with dimensions to get your desired internal volume. Keep in mind that when you are using the calculator, add the desired internal volume (for ex .6ft^3) to how much air your subwoofer displaces(probably around .07ft^3). So for the numbers I used as the examples you would need to plug in dimensions until you got the answer to be .67ft^3. This ensures that your box still has the volume your sub needs.

LuckyFlyingROUSH

Yo Ill write a big post tomorrow on how to build a sub box that will fit a mustangs back seats tomorrow aight? Heres just something that you can do to go get started while I write everything up.

Go to lowes and buy a 4x8 3/4 sheet of MDF and have them rip it to 18inches twice horizontally so there is another 12" strip left. Also buy 1.5inch screws, wood glue, a tube of silicon. (You are ripping it to 18 twice to make two identical boxes so they will fit in the trunk. I think I figured each box out to be around 1.5 cu ft when I was all said and done.
You are going to need a drill, tablesaw, measuring tape, and patience.

I would go with a non ported box, it just sounds better IMO and I could never get the port just perfect when I tried to do ported.