My sub install
 

2017 USDM Toyota 86. Factory Pioneer head unit, stock speakers and door speaker amp.I mainly listen to my music on a USB stick. Classic rock is my preferred, but I have a mix of all genres. Like everyone else I felt the stock system was a little weak. However, at high volumes, with the bass, mids and treble set, it’s not too bad. Like the engine, ya need to keep it cranked up! Now, this is my daily driver and I do carry things in the trunk at times. So I didn’t want to big of a box. I like the fiberglass sub-woofer enclosures that Subaru and OEM Audio+ use. I found this one made of MDF on E-Bay.
Attachment 199641
https://www.ebay.com/itm/11372440561...CABEgLio_D_BwE
It’s made in Poland. It cost $219.00 with free shipping. They do make a left and right box. I bought the just the right. It took about a week to get to me in Florida. The build quality is terrific. It’s a 0.5 cubic foot box for a 10” sub. I looked for a 10’ sub that would work for this size box and came up with this Rockford Fosgate R2D4-10. Dual 4 ohm voice coils I hooked up in parallel for a 2 ohm load. Rated for 250 watts RMS at 2 ohms.
https://www.amazon.com/Rockford-Fosg...ct_top?ie=UTF8
For an amp Rockford Fosgate R2-250X1 Mono amp. 250 watts into 2 ohms. 8 awg power wire with a 50 amp fuse. To get speaker level signals to the amp I got 2 Metra harnesses, 1 male, 1 female, soldered them together and tapped off the speaker signals from the head unit, before the factory door speaker amp, and routed that to the new sub-woofer amp.
Metra adapters for amps 70-1761 & 71-1761 – Amazon.
I made a bracket for the box to attach inside the trunk to the spot that one of the push pins are located. Bought some ¼-20 clip nuts, and a threaded knob and located to the push pin spots. One by the trunk opening, and another by the back seat. Got the idea from the OEM Audio+ install videos.
Attachment 199642
Mounted the amp upside down under the brake light. Total price, a little over $500. I think it adds what was needed.

nice! how did you like the quality of the box? haven't seen that model before.

do you have a picture straight on from the back of the car? i'm curious how far it extends into the main part of the trunk

That box looks like it's built like a brick outhouse - SOLID! I like the placement of the enclosure in the trunk. It's not hanging all the way back behind the rear axle line, stuffed away in the corner. Nice find! :thumbsup:

I think it sounds great. I'm no expert though.

I also did something you recommended. Added a couple of caps inline with the door speakers after the factory amp. Block out some of the low bass. Two 50uF in parallel for each speaker.

Yeah, the box is built really well. Haven't seen one like it on here before. They make them for all different vehicles too.

Attachment 200215

Someone PM'd me asking how the back was attached.