fourth order help

[sh4ggy]

I want to build my first fourth order for 2 re s.e.x15s and I'm not sure if I have a good build planned out what I have is 2cube sealed each with a shared 8cube ported at 45hz .port size is 10x12 just under 11 inches long the out side dimensions are 36x39x21. Any help I could get is appreciated

[TaylorFade]

Did you just like your own post? Lol.

How did you arrive at all of those specs?

[CleanSierra]

I agree with the specs question. I've got similar dimensions planned for my 4th and I'll be running nearly twice that port area. I'll be running 220" of port with 3 sealed and 9 ported tuned at 49

[sh4ggy]

yes i accidently liked it. I came up with those specs from the optimal size for a sealed enclosure from the manufacturers specs then I did a 2-1 ratio for the ported side calculated bracing and 45s then tuned it on 12volt. I'd like to talk to a real pro but those seem kind of hard to come by. I've tried to download Torres but I have a non partitioned mac. And I can't run it. None of the box builders work on mac. If ur a pro plz help

[CleanSierra]

I'm by no means a pro. What vehicle are you working with four this enclosure? It sounds suspiciously like a blowthrough our a big SUV box. I'd get your port area way up on a 4th for a couple of 15s. 2:1 ratio is probably a good place to start. Tuning that low may lose you some upper end output. It may work out seriously perfect though. The vehicle has a lot to do with that. I wouldn't use Torres to try to design a bandpass so you're in luck there. So if you tell me what vehicle, that's a good starting point. What are your goals with this, SPL, good daily bumping system, air moving monster?

[sh4ggy]

and the port area should be right .port side is 8^3 8x15=120 10x12=120. Or do u tune a fourth differently? That's why I'm here to get help. Any given is certainly appreciated

[sh4ggy]

its a 03 Santa Fe. And you sound like more of a pro than me. My plan is to build a fouth for the 2 re's I have now and in acouple month I'm going to buy 2 more and build a b piller fourth order wall. I'd like to do spl mostly but I want to be able to listen to it too

[CleanSierra]

Well if you're planning on walling, that's pretty serious and more than most guys do for just daily listening. As far as your port area goes, you've got subs with a really decent Xmax and and can really benefit from port. The standard 12-16" per foot does not apply here with a 4th. You should have a lot more port, like I said, I'm going to be running 220" in my enclosure and I would have preferred more. You do have a good amount of cone area as well. Have you considered the displacement the port takes up as well? it's big and we'll cut into your ported section's volume. You're on the right track from the looks of it.

[sh4ggy]

this is my first season going to any shows the only thing I wanted to do this season was go out and learn what I should be doing. So far I've won a clue of shows but I've got the itch and I know I could be doing better. Louder punchier. The settup I've built now makes ur head hurt but if I want to move up I have to learn how to do more complicated builds.

[sh4ggy]

yeah I'm a journeyman carpenter and electrician. I've probably built a 100 diffrent boxes for sidework. But nothin' complicated like this. So how do I calculate my port area?