under seat box design for 03 f150 extended cab

[Alex JB]

hi,
searched but couldn't find any plans for a mdf under seat box to house a single 10, anyone have one?
made a cardboard mock up for passengers side only and its looking a little low on cubes, 0.9 right now. was looking to get over 1 and keep drivers side for my in car stuff basket, but full length design may be necessary.

any plans/designs appreciated.

[DBfan187]

I'm in the same boat dude.

[shakin]

hi,
searched but couldn't find any plans for a mdf under seat box to house a single 10, anyone have one?
made a cardboard mock up for passengers side only and its looking a little low on cubes, 0.9 right now. was looking to get over 1 and keep drivers side for my in car stuff basket, but full length design may be necessary.

any plans/designs appreciated.

I'm in the same boat dude.

talk to jack0409 he can help out. he has 2 alpha 12's under the seat that sound great

[ahillworks]

Well I will see what I can figure out but I am sure you are looking for a shape like this. Correct?

[ahillworks]

I did find this here: http://www.fordf150.net/howto/subbox.php



I also ordered two 10” Cadence UltraDrive Z subwoofers from Andy at SubBox.net.



You’ll need a few basic tools to install the box. I needed Torx bits, a ratchet and extension, and some screwdrivers. Luckily, you don’t need any specialized, expensive tools for this install!

The first step is to remove the rear seat. That is done by removing 10 bolts. Two of the (bigger) bolts are at the back of the seat; there are three on each end of the seat, and two at the middle support brace. In the picture below, the bolts are circled in yellow. You don’t need to flip the seat down to remove the bolts, but it makes the job easier. When you put the seat lift kit and sub box in later, however, you will not be able to leave the seat flipped down to put the new bolts in.



Once the bolts are out, you should be able to remove the seat. Be sure to flip the seat back in the normal (locked) position before removing the seat from the truck, to make things easier.



The next step after removing the seat is to remove the center brace that supports the seat. Although you won’t need the brace anymore, don’t worry that this is being removed. There will still be plenty of support for the seat provided by the strong sub box.



Once the seat is out, the truck is almost ready for the subwoofer box. I did a trial fit, and it looks good!



The next thing I did was mount the two Cadence subwoofers I ordered from SubBox.net. I used the crimp style connectors because I didn’t have my soldering iron handy. I would highly recommend soldering all connections. Once I had the sub wired to the speaker connections inside the box, I screwed the sub into the box using ¾” wood screws.



Here is a picture of the sub box with the subs installed, ready to go into the truck:



The next thing I did was run the speaker wiring through the truck. This part is totally up to you as to how you do it. My amp was located under my passenger seat, so I simply ran a few feet of wire. Your application may be different. Then, I put the sub box in the truck and hooked up the wires. I used gold plated connectors. You can see how the whole unit looks here:



The next step is to put the box in its final place, and put the seat back in. This part is a little tricky because there are four spacers that are needed to raise the seat two inches. Two of the spacers are wooden blocks (one at each end of the seat), and two spacers (metal tubes) are used at the back of the seat (where the larger bolts are).

I started by putting in the back two bolts first. This is where I needed to use my ratchet, extension, and wobble socket to get behind the seat to get those bolts in. It’s a tight squeeze in there, but it works! Don’t forget to use the two longer bolts that come with the seat lift kit.



Once the back two bolts were in, I installed the two wooden spacer blocks, one on each end of the seat. I used the enclosed (longer) bolts to replace the factory bolts. You can see the two blocks below:





The only thing left is to put a few screws in place where the old middle seat bracket was. The screws go right into the box, securing the seat and box together. The seat was already really snug, so I’m not ever sure it needed the screws, but I put them in anyway.


--------------------------------------------------------------------------------

Here is the finished product. It looks good – the tan carpet on the box blends very well with the factory tan carpet. More importantly, it sounds good. The installation took about 3 hours for me. If I wasn’t taking pictures, it would have taken a bit less. Feel free to contact me if you have any questions about my particular installation or the truck.
–Kelly from FordF150.net

[ahillworks]

I hope this helps. From the looks of this post I found it seems to be a simple build. and looks at least 1.5 cubic or more. If I had measurements I'd draw it out but I dont.

[Alex JB]

I hope this helps. From the looks of this post I found it seems to be a simple build. and looks at least 1.5 cubic or more. If I had measurements I'd draw it out but I dont.

Very helpfull.
I was thinking of working around the middle seat support, but I like this idea now of removing it and just fixing the seat base down to the box.
Not going for the lift though, my wife complains that there's not enough head room in the back as it is.