Help Designing 4th order Dual 15" Box only 11" Tall

[FadedSpy 10+ year member]

I'm helping a friend of mine design a system for his 2 15" Subs in his Tahoe. He wants to use the entire space behind the back seat which is 48" x 48" . The subs would share the same port and he wants them tuned to 34 Hz. I have no idea how to design something like this or plud it into Torres so I'm looking for some help. The Subs are 8" Deep and 15" wide the total box height would be like 11". The subs would either be up fired or down fired into a 2" port board and the port would be on one side facing back toward the rear of the Tahoe.

Here's a basic idea



I hope this makes sense. thanks for any help!

Click to read more...

 

[Silverado SS 10+ year member]

2" of room above will simply not work, 1 because they Subs may hit the wood and 2 nothing should be that close to your sub because of loading damage. He has a ******* Tahoe there's no reason to only go 11" high. Also in a 4th order you don't tune it to one frequency you tune the sealed side and the ported side and your peak you be in the middle

 

[FadedSpy 10+ year member]

I understand the first part of what you said but you lost me at tuning. He hauls stuff slot and needs to be able to throw stuff on top of the box so that's why we thought a 4th order would be ideal. I don't know anything about them. It'll be for 2 American Bass Xfl 15's

 

[adulbrich 5,000+ posts]

Face the magnets into the ported side so you can smell when you're cooking a coil! It is very hard to hear distortion in a bandpass box. I know from experience.

I don't know how much your friend knows about car audio, but tell him to turn it down if he smells something, lol

 

[adulbrich 5,000+ posts]

Whoops, was looking at your diagram wrong

 

[Silverado SS 10+ year member]

I understand the first part of what you said but you lost me at tuning. He hauls stuff slot and needs to be able to throw stuff on top of the box so that's why we thought a 4th order would be ideal. I don't know anything about them. It'll be for 2 American Bass Xfl 15's

If you don't know what I'm talking about as far as tuning you have no reason designing at the very least pay for a good design before you **** this up. A 4th order isn't just a sealed and ported box put together

 

[adulbrich 5,000+ posts]

If you have the time, a (small) cheap sub, and some extra MDF, build some test enclosures. Play around with the ratio's and the ported box tuning after you do a lot of research. I found that this is the best way to learn (at least for me).

You should just make a ported box for your friend and put grilles over his subs or face them towards the back of the seats. Does he only want a bandpass box because it will protect his subs?

 

[FadedSpy 10+ year member]

If you don't know what I'm talking about as far as tuning you have no reason designing at the very least pay for a good design before you **** this up. A 4th order isn't just a sealed and ported box put together

I told him I would post his drawings and see what we could come up with. I ain't building **** I'm just gathering helpful information for him

 

[Silverado SS 10+ year member]

I told him I would post his drawings and see what we could come up with. I ain't building **** I'm just gathering helpful information for him

Well scrap this idea and start over then, not trying to be an ******* would.just rather not see you or him mess his **** up, there's a lot of great thread around the web on 4ths if that's really what he wants tell him to read til his eyes are blood red sleep then read more. Scrap this box design and see what else he can do or at the very least raise the box up 5" figure out what your sealed portion is tuned too and adjust length (front to back) from there

 

[FadedSpy 10+ year member]

Maybe something like this will be better for him

http://www.caraudio.com/forums/high-output-enclosures/535560-high-output-enclosures-picture-log.html