anyone see anything wrong with this design?

[geraldwp]

i am currently working on design a box design for 2 Fi BTL 18s. The box is roughly around 14-15ft^3 after port and woofer displacement. this is going in a 2003 ext cab silverado.

here is what i designed in sketchup. going to be running a audioque 3500d to each. dual alts and 2 kinitek 2400s in the back.

box dimensions are 24"x24"x57" with 18.5"x12" port opening with a depth of 20".

the box height may change a little but not much. just looking to see if everything seems pretty close. any comments will be appreciated.

i know this is my first post here, but ive been on here and some other forums for a while. thanks in advance.

couldnt get the pic to work, so go to this please

Edited October 29, 2009 by geraldwp

[Marlo Stanfield]

With 3500 watts per woofer I'd suggest droping the box volume sum or you might run into some issues with that amount of power in that size enclosure. I'd personally suggest like 6ft3 per woofer on that power, tuned to like 33-35hz w/ 75-80sq in of port per sub.

Also I'd add maybe another big batt or two in back just to be safe. You can prolli get away with it due to the dual alts but electrical wise, there is no such thing as overkill.

[geraldwp]

ok. i think at the moment its around 7ft^3 per sub and tuned to 35hz. i got my port area with the ol 16 in^2 per ft^3 calculation. any idea on possible dB?

[Gotz1lung]

electrical wise, there is no such thing as overkill.

This, this, this....

And welcome to SMD mang!

[korey_hofer]

2 18's common chamber with alot of power do 10ft that is what I plan to use with my sigs with 5k each

[Marlo Stanfield]

ok. i think at the moment its around 7ft^3 per sub and tuned to 35hz. i got my port area with the ol 16 in^2 per ft^3 calculation. any idea on possible dB?

That is somewhat rule of thumb regarding port area but by no means is the best option in every setup. I will generally go anywhere from 10-18in^2 per ft3 depending the power, subs, enclosure design, etc.

There is no way for us to tell u what # you might get, all we can do is take *very rough* guesses. What vehicle is this going in??

[geraldwp]

yea i understand what you mean. its going in a 2003 ext cab silverado, and thats all im looking for, just a close guess. im probably going to work towards the specs you suggested.

[Marlo Stanfield]

Well I'll assume that you built a stout enclosure and voltage drops are kept to a minimum w/ the electrical u have listed... If it's anything under a 150 @ the dash would be a serious dissapointment for me, so I'd say anywhere from a 148-153 @ dash all sealed up. If u were @ a 153 all sealed up I'd be thoroughly impressed to say the least. There ya go I gave u a 5db range, hope that at least gives u something to work towards when you're building it all up.

Last thing I almost forgot was to tell you to remember to have a lot of bracing in that enclosure. Threaded steel rods work great and is what i'll used for higher power setups like this. Wooden dowels also work well and like the threaded rod, take up very little air space inside the box. Remember to do at least a double baffle on the "face" of the enclosure, maybe even a triple baffle if you're feeling it lol. Another way to strengthen the enclosure and to pick up a few tenths is to resin/glass the inside to make it almost glassey smooth. Another slight addition like that is adding 45s to the box corners where the most airflow will occur, they'll help the score/strengthen also.

[Gotz1lung]

ok now for a helpful post.. I looked for my cut sheet, but no luck..

I have a Sierra, so from the past 4 setups this is what i ended on that i personally was the happiest with.

If iirc about 20-21in depth is all i could squeeze and the seat still be in a comfortable position(im assuming this is daily)but i got some long ass monkey arms.

If this happens to be your case i would suggest doing subs/port up.Ill have a SU for ya in a few. I would also not go any wider than 62 1/8 unless you want plastic parts rubbing holes in them selves on the side of your enclosure. if your loosing the interior panels then disregard..

Are you trying to stay under the window line? If so, after my shelf got in i didnt have 24in tall, more like 20.I used the rear seat belt bracket holes to bolt the shelf down to have a solid base to secure the enclosure.

Heres a few pics of my junk..but it does do 143@43hz on 1500w rms.

[Marlo Stanfield]

^^^ That looks clean as hell, especially the amp rack.