Ext cab, under seat spl? Critique my design.

[jake21 10+ year member]

Ok my mission is to fit two 12" type r's (yes, i know.... type r's, its the main brand i sell at my shop) underneath of my rear seat in my 03 silverado. I want to keep the back seat but still be able to throw up some decent numbers. Im not looking to hit 150 or anything like that lol, id like to at least be around the 138-141 range,

anyways the arghsss will be ran off Alpine's M2000 (2000wrms @ 2) and here is a quick design i threw up in google sketchup, im looking at about 3.5-4cft after displacment.

Trying to use an 8" aero, but might have to resort to a 6"...

Oh and btw i will be making a new seat all together with the box being part of the seat.

Subs downfire in a "sorta" clamshell design with the port to the drivers side.

Loud? Not Loud? Average? Funky Pup?

Click to read more...

 

[pro-rabbit 5,000+ posts]

Interesting idea, I would be curious to see how the subs load in that design. I would try to get around 4ft3 net and a 6" port would be fine, I think with an 8" the length and the overall size might be more of an issue.

 

[jake21 10+ year member]

Interesting idea, I would be curious to see how the subs load in that design. I would try to get around 4ft3 net and a 6" port would be fine, I think with an 8" the length and the overall size might be more of an issue.

One thing i forgot to mention, the box will also be designed around a interchangable aeroport so i can tune it down to around 33hz for daily driving (as its my daily driver) and then ill shorten it up for comps. Anyways, 4cft will be ideal if i can squeeze it out of the space i have, the type r's dont sound half bad at 33hz in 4cft either.

My one worry is loading, just like you said, the hump, i believe i can get rid of it if need be and raise the box up a bit on that end. Ill post a new revised pic in a few mins

 

[dbjunior 10+ year member]

The small clam shell will work great it will create a similar effect to a sixth order bandpass the tuning you use on the box itself will tend to be real peaky so you should do well for your goal and get great lowend tuned to 33

 

[jake21 10+ year member]

Alright here are some revised ones, this is with it raised off the ground 5 inches (how tall the hump is in the center of the truck)

 

[dbjunior 10+ year member]

Id say the first would be louder but you will get a smoother response with the second

 

[jake21 10+ year member]

Threw in some supports. Still looking decent?

 

[jake21 10+ year member]

And one last design, which one will be best overall for my goals? SPL and SQ with interchangeable port.

 

[Louisiana_CRX 5,000+ posts]

Id just say fvck it and remove the back seat and do it right, do it big.....

 

[jake21 10+ year member]

my guess is the last one, fewest flow restrictions

 

[jake21 10+ year member]

Id just say fvck it and remove the back seat and do it right, do it big.....

love too.... cant tho, need the back seat. i use it almost everyday. thats also one of my goals is to be slightly competitive while keeping a somewhat-stock appearance

 

[DMT Allstar 10+ year member]

if i could make a small suggestion, why not build the box up in the design that you have here but where the hump in the floor starts on the side next to the sub, fiberglass the rest of the bottom all the way over to the port side. you would be able to gain a little bit more airspace and it would fit better over the hump and on the rest of the floor while maintaining the structural integrity of the inclosure. just some food for thought. i like the design of the enclosure and the idea of the interchangeable port. very cool!

 

[Trancer 10+ year member]

Out of my experiences with the newer Type R's, they really like a lower tuning. I know you are going with interchangeable ports, but I think you will like the lower tuned port and wouldnt go back to the higher tuned port. I was running my two Type R 12's at 34 hz and then build a box at 31 hrz and the difference was very noticeable. They really hung on to those lows really well and honestly, it was louder with the 31hz build. The box was the same, just tuned it lower.

So my recommendation with the two ports is to have two aero ports, one at 31 hz and one at the 34 hz. I think you would really like the 31hz port.

 

[audiobaun 5,000+ posts]

At the time I installed a pair of subs under my seat in a 98 xcab, I ended up raising up the seat approx 4in, to get some space, welded theangleIron, ect, and worked just fine to get more than what I needed, and was still functional for passangers

 

[Trancer 10+ year member]

Just noticed this thread is a few months old. Woops