4.8is DSP subwoofer upgrade: I'm ready...

[UCrewX5JR]

Originally Posted by xsx450

did you have someone build the box? do you have a cut sheet for it? I want to add a sub but i use most of my trunk space on the weekends...

Honestly I just went to Home Depot and got a 3x5 sheet of 1/2" MDF (Medium Density Fiberboard) and a can of leakseal and just measured and cut as I went. When the box was all done to make it totally air tight I coated it a few times with that rubber spray inside and out. I can pull my box out this weekend and post some pictures and measurements if you want. What I like about mine is that with the DSP custom settings the 80 Htz control is essentially a built in gain control.

Leakseal

MDF

Kicker L5 Subwoofer

When I was designing my box I didn't want to mess with creating a port that went down to where the spare tire is like zerochief did http://www.xoutpost.com/bmw-sav-foru...installed.html. I wanted to make sure I slightly exceeded the minimum cubic footage required for the L5 subwoofer in a non-ported box so I removed my fuel door lock actuator to gain the extra room, but it wasn't totally necessary. All you would need to do is shorten up the top of the box by 1/2" and you wouldn't have to worry about taking your actuator off and would still be right around 1 cubic foot.

With the right tools and carpentry skills zerocheif's DIY is a home run, I just lacked the woodworking abilities (and patience) required by his method.

Someone who you should contact is mrbmwx5 I'm pretty sure he was able to take a hacksaw to the stock DSP box and put his own shallow mount 10" in place of the two small ones that come stock. This will still require an additional amp to power the new sub and good quality shallow mount subwoofers are not inexpensive either.