I am about to start buildin my box and getting everything ready for my new system. I already have a Fosgate Power 1001bd which is 1000 watts @ 2ohms. For subs i plan to use 4 M.A. Audio 12's or 4 Kicker CVR 12's wired in series to a 2 ohm load on the amp. I know these arent great subs (I used to have a JL W7 12) but with the design i have for the box its all mainly for looks. I plan on build a hatch style box with the 12s located in each corner of the box, then having the exterior of the box rhino lined, then having a diamond plate iron cross cut out and rivited in the middle of the box in between all the subs. My question is about airspace. With the plans i have now its all equating out to 12 cu.ft. or more and i need closer to 8 cu.ft. Is there any kinda of way to take up airspace in the box with out actually making the box smaller? I thought about some kind of foam like for using around pipes and stuff but im not real sure what that would do to the sound. Any idea's?

 

Yes, you can make the box smaller to its specs. That would be the most ideal thing.

But if you must make a big box and nothing but a big box b/c your sorta **** on your idea then what you can do is go to like Lowe's or Home Depot and by a 4 " X 4" X (whatever you need)" and buy wood. Wood will NOT flex or give in. This is what you need. Other materials willcompress under the pressure making your insides unstable.


Get some blocks man. Get some blocks of wood and calculate that into the math of airspace you need to have.....

Hope that makes sense...

 

Yeah I could build it smaller but its beeing built for show and the size is important to integrate with the other things going in and on the vehichle. Ive built around 7 or 8 boxes and I use 3/4" MDF and silicone sealent. I've got really good experience with building boxes but ive never had a problem of too much airspace before. If looks wasnt the main issue i would make it smaller. Im most likely going to build a "box within a box" so to speak. Where the subs have boxes to match their specs and an outer shell to match the size specs i need. Its goin to be harder to build but it should sound right and i will get the look i need.

 

It should be a project that'll be fun. Just take your time and do it right. I have a habit of trying to get things done too fast as I am too eager to wait for results.

Good luck. and post up pics. I guess this site doesn't let you post pics. Oh well, heres this...

 

If you don't mind, I'll tell you what I did in my Expy. I kept the factory door speakers, (Eddie Bauer so the speakers were good to begin with), I added 6 tweeters, 1 set at the tops of the A-pillars, 1 set at top of B-pillars, and 1 set at top the very back pillars. I added 2 round 6" speakers to the panels in the rear, right by the wheel molding, removed the 3rd row seat and put in a box that is totally enclosed but have 4 port holes. In that box 2 sony xplode 12'' face eachother, I bought this box in a store. I replaced the ford 10" woofer the Expy came with a sony xplode 10". I have a 1000 watt sony xplode amp under the back seat. I'm not lying to you, you can here me coming from 3 blocks away! The only thing I'm about to change out is the factory head unit, which does not hesitate at all, but I want a mp3 player, that is the only reason I'm replacing it. As for the air space you inquired about, I notice that opening up the rear vent windows, it pounds even more, as that increases air space.....

 

That sounds quite interesting. That's called a bandpass box

I don't like to mix sub sizes due to cancellation problems and i wouldnt put tweets or mids all the way in the back cause no one sits back there to hear them and as far as sound quality goes it sounds alot better to have your mid and high frequencies coming from in front of you than from behind. With subs we're pretty much stuck with keeping them behind us. With the exeptions of those like cgorris who has in mounted in the middle up front. (I really like that idea)