ok...as of right now i have one 12" sony xplod sub powered by a 600 watt kenwood amp (old school good one!). well i have gotten the bass fever where what you have is just not enough! i want more! i have been thinking about going with 2 12s. anything bigger would just be too much in my little truck! well i have been thinkin on how i want it set up and i finally drew it up on MS Paint. this is how she looks:



the overall measurements of 40x20x16 is the biggest it can be cause well....its all the room i got! the two end boxes are going to house the subs and the middle box is going to hold the two amps(two amps because i like that look better...i think it will look cleaner). and one deminsion i forgot to include is the hight of the amp box which would be 3/4 the hight of the sub boxes so that would make it 15in. oh and just incase you were wondering....the dead space below the amps in the middle box already has some plans for it. well now comes the slew of questions that i have for this project...

i will be building this myself so:
1. which size MDF should i use... how thick?
2. how should i seal this bad boy up completly! caulk and screws? if so what kind of caulk?
3. its going to be sealed boxes because i listen to alot of heavy metal and the sound quality of a ported box with double bass isnt very good so which subs would go well in a sealed box with those dimensions? (kickers are out of the question cause i know they require ported boxes)

i know i have more questions but i cant think of them right now. but this will get me started.
money is not a worry in this and niether is time. i plan on taking my time building it so it will look right and while i am building it il will buy the subs and amps peice by peice. thanks!

 

I'd use 3/4" MDF, glue all joints with carpenters wood glue, screw together - about 3" apart for screw spacing with 2" or longer deep thread drywall screws (pre-drill all holes first) then caulk (regular silicone caulk for windows works for me) everything from the inside.

Some Kicker subs are suited for sealed enclosures, you just need to do some research beforehand.

I like the sound of sealed boxes over ported ones also. I think the sound quality is much better & tighter than ported boxes.

 

thanks bugg man! yeah i do need to do some more research. i think instead of goin with two 600 watt amps im just going to go with one 1000 watt amp. so that will change the plans a bit. but now i gotta find which subs will work best with the airspace that i have in the box.

 

ok...so how would i go about finding the cubic footage inside of one of the boxes if it is 20x15x16. 20 being the hight in inches, 15 the width in inches and 16 being the depth in inches.

 

multiply them together, than divide by 12

 

nope

L*W*H = volume in cubic inches. To find cubic feet, you should divide by 1728 instead of 12, because there are 1728 cubic inches in a cubic foot

Also, to find the volume of the inside of the box, you need to subtract the width of the wood you're using.

Ex: if the height from outer edge to outer edge is 20", then the inner height is actually 3/4" less due to the thickness of the upper piece of MDF, and 3/4" less due to the thickness of your lower piece. Your interior height is actually 18.5".

Correcting for the thickness of the wood, the interior volume is 18.5" * 13.5" * 14.5" = 3621.375 cubic inches

Divide 3621.375 / 1728 and you get 2.099 cubic feet per box

 

Use polyurethance glue (or the Gorilla Glue you see at home depot). It expands as it dries and forms an excellent bond to MDF. I then run a 2nd bead inside the finished product, and it's air tight and indesctructable.

When calculating inner air space, you have to account for the thickness of materia. A 12"x12"x12" MDF cube is not a cubic foot. With 3/4" MDF a 12x12x12 inch cube will have inner air space of .669 cubic feet (minus whatever volume your sub takes up). Yes, sadly, this is one of those times your high school algebra teachers were right!

 

why did i never pay attention in math! oh well... but i was looking at some rockfords. the P3 line of subs. the one i was looking needs .75-1.25 cubic feet of air space in an enclosed box. and the mounting depth is 6.75". so how much does that sub take away from the volume?! ahhh...its so confusing! did i mention that i hate math.... oh and by the way...these are the subs i am looking at sub go BUMP!

whatcha think? for 200 bucks a pop i dont believe it is too bad. RMS on them is 500 so putting two of them on a 1000 watt amp would work just fine!

oh and thank you very much Bhavesh for doing what i couldnt do!