I will show you guys my project that I completed in just a matter of 2 hours after getting my tools together. I wanted to get good bass..... that's all I wanted. Not something that you can hear a mile away but something that I can hear the low's really well and that thump needed to be just right. After taking it to many stereo shops I decided to give it a shot. Keep in mind that the E39 trunks are sealed shut and have rubber foams and other sound dampers to make your ride quieter. Of course that's great but sucks when your trying to get sound sound from the trunk.(See step 3 below) I never did anything like this before but I'm pretty handy so why not :rofl:
Things you will need for the DIY job:
Dremel, screw driver or power drill, PVC foam strips, screws, ratchet/proper socket, wood face plate for sub woofer(best way to get it done), and also sub woofer.( I chose 10" Rockford Fosgate R1"
--Now, trust yourself a bit and don't be shy. Let's get to work.
Follow these 3 steps before doing anything.
1) First thing, open your trunk and locate the fiber glass cover which covers the sheet metal attached to the rear seats. There are 4 plastic flat head screws. Once removed, put that fiber glass cover aside we will come back to that in the end.
2) Now, go into the back of the car. It's time to remove the seats. To take out the bottom half of the rear seats you must grab each side side of the seat and tug upward to un-clip the seat from the body. After doing so it will be a little loose all you have to do now its just pull it outward toward the front seats and it should be out now.
3) Now to take out the upper half of the rear seat we must locate two bolts which are on the bottom two corners of the upper half of the seat. They are a little hidden but there are only two so take your time. After that make sure to pull out the head rests. Tug hard upward and that will take out the head rests. It will make the process a lot easier.
---You will see the foam material I was talking about earlier. So this stuff is main reason why the lows of the bass can't travel to the cabin of the car besides the sheet metal and other foams. You can cut it completely to get more sound however I did just enough for the sub and its perfect!
Now that we have some room to perform the job lets begin!
1) This is what it should look like after you have uncovered the seats and exposed the sheet metal and thick foam that make cabin quieter. ( I have already cut out the rubber to my liking and also traced the wooden face plates insert to the sheet metal.
2) After you have traced, you must now start using the dremel to make the cut that is needed to accommodate a 10" sub woofer. After you are done, it should look like this(you make choose to sand the sharp edges if you have any, in my case the cut was pretty clean and I chose to leave it as is)
3) After you have made the cut, make sure you take your sub woofer and slide it in the hole we just cut out. This is for precaution so we get it perfect the first time.
4) I chose to go buy PVC foam strips($4) to that I can have an even air tight seal from the sheet metal which does not have a flat surface. So when it's time to bolt the wooden face plate to the sheet metal there will not be a air leak when the bass hits. (Remember the better you do for this task here, the better sound you will get. I chose to apply only to areas that were not even so I cut and cut until I was satisfied. While you do this make sure to put the face plate on the sheet metal and press it using your hands to see if it creates a good seal. Here's what mine looked like after I finished:
5) After make sure to drill holes where you want the screws to go in from your face plate into the sheet metal. The metal is very strong so you cannot just drive just the screws using a power driver. Once you have the face plate bolted on, go ahead and screw in the sub woofer onto the face plate.( I used 4 large thick screws to bolt the wooden face plate to the sheet metal. That is so that the thump of the bass will not shake it loose in the future) IF YOU DON'T HAVE FACE PLATE YOU CAN CUT ONE OFF OF A 10'' ENCLOSURE. You may also go to Home Depot and get desired size and they will cut it for you.
This is what the final result should look like:
---Once you'r ready to put the fiber glass panel back together in the trunk. Make the desired cut for the subs magnet to stick out.
---This set up just sounds amazing!!:rofl::thumbup::angel::lmao::beerchug: