Alright, I finished several hours ago but just now took a pic and have time to post it.
As with most of you, I have noticed the underwhelming performance of the stock Bose subwoofer unit. I cracked it open the other day and found three things.
First, the amp inside the speaker box is pathetically small, and rated at 100watts. I don't know how they rate things at Bose but I own a 15watt tube amp that is 5 times the physical size. I could go into more detail but suffice it to say, that amp is the product of space constraints. The end.
Second, the dual 6" speakers are not nearly as bad as I expected. They aren't meant for ear splitting volume levels, but that considered they could be a lot worse.
Third, the box itself is very well designed. It's a ported enclosure utilizing a relatively simplified version of the proprietary Bose "waveguide" design, has almost no internal right angles, is surprisingly rigid, and very light. Plus it fits into the spare tire, which is a huge bonus IMO.
Anyway, just as I was thinking about replacing the pitiful sub amp, I happened upon a 200watt monoblock JL Audio amp on craigslist for $35. Giddy-up. I picked up a PAC adapter for $25 to avoid running wires from the back of the head unit, an 8AWG Phoenix Gold amp install kit from a local stereo store, and began modeling the removable tray on which I was going to mount all this stuff. The reason for mounting everything to the tray is so it can all be removed quickly and easily if I want to throw the spare tire back in to go somewhere outside cell phone range. I finished up the modeling last night and woke up early this morning eager to get started. All in all, it took about 4 hours and just under $100 for the whole thing. I don't know how to show you the results beyond the following pics, but trust me when I say the difference is night and day. I am not even thinking about upgrading the sub anymore, and now run the "bass" level at -2 to keep things even. Here are the pics:
Solidworks model of amp tray with amp and adapter - top view:
View attachment 203754
Solidworks model of amp tray with amp and adapter - iso view:
View attachment 203756
Pic of the whole thing installed: (I'm going to hide all the wires tomorrow)
View attachment 203757
Also, this DIY help tremendously: ///2811
EDIT: I adjusted the input levels on the amp this evening so it runs with the "bass" adjustment at -0-. The sound quality is drastically improved, the volume only slightly. I also timed a full removal, which included pulling the fuse @ the battery and unplugging everything from the tray, at a little under 4min.