well i have 3 12 in subs in my blazer but i have one duel box and a single box kinda sitting on top and its kinda clumy and so i stared making plans for a triple 12 ported box and i i just want post my plans to see if anyone sees any big flaws or if they have tips lol thanks

 

One thing for certain is that you need to have a full design in order to make it work properly. I'd be glad to help you with it and can get you cut sheets and sketchup drawings so you know what you're looking at. Are those the maximum dimensions you're willing to go with the enclosure? What subs do you have? I can get you something drawn up fairly quickly if you'd like me to.

 

i have two kicker comps and a rockford and thats more of just an idea that i know will fit for sure (i started with the demintions for my duel box then just went out a bit more) if you have layouts that would be cool ive made boxs before but nothing very elaborate so i figured id give me a challenge and try it out lol and im more then happy for some tips for what works and what dont lol

 

One thing to mention is that mixing drivers is typically not the best thing to do. Due to the differences in the electro-mechanical properties of the subs it can cause response problems. Such as dips or peaks in the response, cancellations, harmonic distortions, and other issues. Not always a problem for most people, they don't even know they're hearing it, but there is some shape, form, and level none the less.

That aside, the box you've got drawn up is a popular configuration and can be well executed in most cases. The difficulty of the build is usually not a problem for the avid builder and acoustically the enclosure can/will work well in most open vehicles like hatchbacks and suv's.

I'm wondering what you're powering the three subs with, and what the wiring configuration and such is. Are you planning on upgrading any or all of it at a later date? If so what equipment are you looking at? I'm only asking about this so I know how to help recommend some things with the enclosure.

 

well i guess i will start from front to back lol i did the big 3 upgrade with 2 gauge wire (overkill but ehh) then i have 4 gauge power running through the truck to the hatch ...cheap sony explode cd player..as for amps i had the duels running on a kicker 800 watt amp and the rockford on a xplode 760 ...but im goin upgrade to one bigger amp (not sure yet but open to sugestions) and also put a battery in the back to run the amp off of ...its a start lol

 

im not really goin for like a compitition system ....just somthing to **** off the punks that ride up next to me thinkn they are badass with duel 10s or somthing lol

 

I can understand that. At any rate I would suggest buying a sub to match the Kicker's at some point in the future just to save the mix/match hassle. I am assuming that the Rockford is a P1. Are they all single 4 ohm voice coils? If so to run all three you'd need an amp that is 1 ohm stable as three 4 ohm drivers in parallel gives a 1.33 ohm load. If not then that's another good reason to get a matching sub. If the subs connected to the amp aren't of the same coil configuration then you won't get an even power balance between them. A Kicker DX500.1 is one ohm stable and would deliver 500 watts into the subs which is pretty close to the rated RMS of the trio you currently have and just a tad over if you replace that Rockford with another Kicker comp.

All the subs need around 2 cuft ea. for a ported enclosure. The enclosure will need to be around 6cuft NET, that's before port, bracing, and sub displacements. With port, sub and bracing displacements your enclosure will be in the 7.5cuft range. That's using a port that is 20"x3" and 15.25" long for a 35hz tune. To fit that requirement the box will need to be a bit larger than you drew up. At 34" wide x 14" tall it would need to be about 30" deep to accommodate your size requirements.

I know that sounds absurd, but to give you a better visual on why that is here's a picture of a box I drew up for a design I had in mind for my Jimmy. It has holes for three 12" subs, but only one would be a working sub, the other two are passive radiators. This enclosure is 2.55cuft NET, 2.95cuft Gross (after sub and PR displacements) and is up to these dimensions, less than half your required size and it's 15.5" deep.





Just some food for thought.