subwoofer under center seat???

[travisr1988]

Hi guys, I have a 1979 Chevy c20 and want a sub in it, I have subs already, but I can't find a box that will fit my subs and behind the seats. The seats are the 40-20-40 aftermarket seats that were popular in these trucks, they have a center seat and console that flips up. I would like to place a single 10" sub under the middle seat, while keeping the center seat functional. Has it been done? Does anybody have pics and/or advice on how to do it?

[blazing816]

I have not done it for those seat, however I hook up car audio/video ad have done I whole lot of custom applications. First you need to start with is if you want a ported or sealed box (this depends what kinda sound you want). Sealed normal give a cleaner hits but tend to be a little quiter. Ported/banbase boxes are loud (tend to be the ones you can hear drive a block away) however these can give you more splatty sound if you do not have the correct componets. However becasue you are trying to fit it under a seat you will probaly have to go with a sealed box because the requirments are smaller cubic inches.

So what you need to do next is have the manual or look what the model of your sub to find the recommened sealed box size (12" is usally close to 1 cubic foot). So then you need to measure the space under the seat and see if you can get to that size that was stated. If you build one too small you can blow the sub because there is not enough space for the air. Plus you need to make sure the profile of your sub will fit (meaning from top of cone to end of magnet will fit under it) because they do make slim line sub to fit in smaller places.

The box should be made out of at least 1/2" MDF (i always use 3/4") and you need to calculate taht into the demension because the recommened box size is for inner demensions. Also so you do not leak air....you should also seal the cracks with acustic caulk or similar.

If you do not want to make your own box, find out what year, make, and model seat come from and see if they make a pre-made box for that vechile.

Let me know if you have any more questions.

[travisr1988]

My subs call for .75 cu. Ft. for sealed box. Seats are an aftermarket style, not factory in any vehicle, they were commonly ordered through conversion companies. So a premade box is probably not around. I can only clearly see 1 issue...i will have to cut some seat frame and either use the box as frame or reroute the frame, seeing as the seat it self is held to the frame by 4 small trim screws I don't see an issue with eliminating the frame pieces there.

[blazing816]

Well thats nice, that is a small box. If you use 1/2" MDF you can make the box 12"x12"x12" outer dimension so that should be easy. Because with 1/2" MDF that is an inch off each side for the inner which means it would be 11x11x11=1331 and to find cubic feet divide it by 1728... 1331/1728=0.77 cu. ft.

Or if you do not have a foot of height you could try and make it longer and shorter to fit under seat (again depends on the profile of your sub). if you made the inner dimensions say 9Hx12Wx12L=1296 that is exactly 0.75 cu. ft.

Also take into account that the subs cone will move (vibrate) some with the hits (depending how loud you have it. So if your pointing the sub down to the floor you would need to put feet on it to raise the sub off the floor. Or if you point the speaker up into the seat. I would make sure you have a nice sturdy metal speaker grille, unless the frame makes it that the seat cannot bow in the middle. Because you do not want to set something heavy on the seat and have it hit your sub.

Honestly your best bet for these trucks is to put the amp and speaker behind the seat up against the back wall of the cab. Because the seat have a natural angle to them it will if in the bottom part of that. You can make the box look like this >   /_|

Here is a picture of a pre-made JL audio box for behind the seat:


Here is a homemade one someone made for a 62-73 Chevy Truck (same concept as ours) he also made a spot for 6x9 since the stock 10x4 are horrible:



Hope this helps.

[travisr1988]

With these seats I would need shallow subs to go behind the seats, and a center cut out to allow the center console to flip up. I have about 8" from floor to center console in upright position that I can use if needed to make the box big enough.