Added 10" sub to stock JBL system in 2nd gen in not the smartest way

Howdy all!

Like the title suggests, this is a ridiculous way to do things as you really should just ditch the whole JBL system rather than piecemeal in parts as I've done. Don't do what I've done, I am not smart. I started this project because i got some free gear and I got laid off so had too much free time. This is my first post as a member and I am excited to actually share a thing that I did as I think it is slightly different than others I've seen, because I've added a sub and ditched the original sub but kept the rest of the JBL amp and speakers, but not head unit. Like I said, not the smartest way.

I have a 2005 TRD Sport, with a Pioneer AVH-X391BHS head unit connected to a pac-audio rp4.2-ty11 processing signal to the original JBL amp. I, for now, am keeping the original JBL amp and speakers, but have removed the stock subwoofer. For my new sub I added a Pioneer TS-A2500 LS4 10" sub connected to a JL 500/1 amp. Shout-out to TRD Toy85 for their post on how to build a subwoofer box that fits my needs, as well as wiring diagrams that are in there!

I like many others got tired of the poor performance of the JBL system and wanted something better. I was gifted the sub and amp, so I figured I should start there! Unlike other posts I've seen where people left the stock sub I just needed it out of my life. Below are some photos of how the project turned out! So far its a large improvement, and I'm hoping to become an employed person again so to make use of the amp rack below and finally completely ditching the JBL system.

As I'm writing this I realized I should have taken more photos. Anyway, I basically followed the plans given in the above post by TRD Toy85 to build the box. Then I took out the old sub box and amp. I built an "amp rack" out of plywood and coated it with 4 coats of Flexseal in hopes that the rubber would cut down on rattles.


Relocating the stock amp to that board was easy, I just flipped the mount on the right side so that the mounting bracket was closer to my amp rack. For a while it kinda sorta worked ok, but the rear speakers would do weird things. After some research I found that they do indeed run in parallel with the stock sub so I soldered in two 2ohm resistors where the old sub was, and mounted those to my amp rack.


The sub fits just like it did for TRD Toy85, and sounds great! I ended up covering that as well with 4 coats of flexseal. It only mildly vibrates at loud volumes, but I suspect that will go away once I add sound deadening.


Next, when I have a budget for fun again, I plan to add dynomat or equivalent, also take out the rest of the JBL system and replace it with a 4 channel amp. I've been eyeing the JL JD400/4 amp for a while now.