kicker cvrs

How would I fit the sub if the box was only 4" in height? I saw on that q logic that it's drilled out or something on the inside were the magnet suppose to be? I remesured the larger under seat portion and I could only go to about 35.5 inches,in length if I built the box 35.5" in length and 14" width by 4" in height it still wouldn't be enough. Its only 1.15cu ft without puttin in the displacement. The seats already raised 1" it's already pretty darn high. I don't think I could get it up higher without it being safe.

the mounting depth on most small 12" subs isnt usually that much. if you plan it out carefully then you can make it work. the only problem might come if the sub you chose has a vent hole in the back of the sub, you want to leave some space for that port hole to breathe. even if you have to cut a 1/2" spacer ring to make the sub fit it will still be better than having a miss-matched sub and box. it will probably take a little bit of research to find the perfect sub but it is out there.

so the Qlogic box had a vent whole in the back? or would it be the sub that required a vent hole for it to fit? wouldnt that let air out? then it wouldnt be completely sealed. i calculated the box i have now for my 2 10" kicker comps and it was somewhere around 1.75 cu ft. idk if i did that right but if i were to calculate for a new box i would L x W x H. so if i made a box that was 35.5" Length x 14" width x 4" height then i would divide the answer by 1728 and it would equal 1.15 cu ft? the only reason the length is kinda small is when i measured under my seat thats all i could fit. i was looking into these subs http://www.frys.com/product/5634871?site=sr:SEARCH:MAIN_RSLT_PG they only need .88 cu ft and from what my calculations said it would have 1.15 cu ft would that be enough to give me some deep bass? they are only 4 5/8 mounting depth but im not sure if i will get what i want?

no the vent hole im talking about is on the back of the subwoofer itself. it has nothing to do with the actual box except that you need to have enough depth inside the box so you dont block this vent. the box will still be sealed. not all subs have this vent though. your method of finding the cubic footage is correct but you have to make sure you account for the thickness of the wood. this site has a box volume calculator HERE that might help you. to find out if you have enough depth for any given sub all you need to do is take your overall box height, 4" in your case, and subtract the thickness of your building material, which should be .5", and you get 3.5" of mounting depth available. if your sub is deeper than that then you either need a deeper box or a spacer ring. if your sub has a rear vent then i would leave at least .25" extra between the back of the sub and the box so that the sub can breathe better.

Awesome thanks! Looks like I'm going to start building soon! Just gotta find the right subwoofer for the job. Will I run into trouble with the 1/2 in Mdf over the 3/4 Mdf?

you just have to be more careful with shooting screws into 1/2 inch MDF. you need to pre-drill every hole or you will split the wood. you have to worry about the same thing even with 3/4 MDF so its not much different. also you might need a small brace from top to bottom to make sure the bigger pieces of the box dont flex.

Oh okay would it be beneficial to use the 3/4 Mdf for the height sides so they would be stronger? Or would that be mixing thicknesses? Which will mess up my calculations?

not necessary to use any 3/4 MDF. you can if you want but i would be trying to save as much airspace as possible.

Okay coooooo!! I'll most likely go with 1/2 anyways. Would the Polk audio subwoofer in a custom box I plan on making give me anything more than what I have with my 2 10"s? I jus don't want to buy the sub for $300 and then have nothing more than what I have now? I'm just trying to cover all my bases sorry if it kinda repeats!!

unfortunately i cant tell you with any kind of certainty that one system will be louder than the other. changing your system is always a gamble, unless ofcourse you so from a single 10 to a pair of 18's, but comparing two 10's to a single 12 is a little harder. it totally depends on the quality of the install. i can tell you that you should see a slight gain because you will be sending all of your power to one sub instead of sharing it between two subs. this is also why i recommended you to use a downfire design so that the bass can hit against the solid floor instead of being muffled by the seat. what polk sub are you buying for $300? that seems really high to me for a single 12