I'm not an audiophile by any means, and it won't shake your car apart like some 400 or 600 RMS system would, but it adds the bass that you can't get from door speakers, and a bit more. Plenty loud enough to fill the cabin of the Insight. It's rated at 600w peak, 150w RMS, and cost $99 on Amazon. I opted to spent the $6 extra to get the wiring kit for it. I was able to turn the bass down in the door speakers and eliminate 90% of their rattling due to just being mounted to the plastic (I haven't mounted them to the doors yet). Here's the link:
https://www.amazon.com/Rockville-RW8...dp/B073W5ZMWN/. They also have a 10" variant as well.
I wanted a powered sub so I wouldn't have to mess with a separate amplifier, and from researching it seems to have the best specs for the price, and one of the lowest prices for the specs. It comes highly reviewed as well. I'm really pleased with the output, it's pretty impressive for just a 8" under-seat sub without much space. It comes with rubber mounts that can screw into the floor carpet. Others have used rubber tubing to hold it in place.
I also spent $8 for 1 1/18" acetal rod to make spacers for the seats to lift them up slightly for the sub, and $5 on longer, grade 8 bolts for the seats.
Since I'm ditching the rear speakers for now, the sub was really quite easy to hook up. Power connected to one of the Meanwell outputs behind the seat, and I used spade connectors to tap into the rear speaker connectors, and then connected both grounds to a bolt behind the center console. I mounted the sub beneath the driver's seat since the passenger seat is out at times. Really the hardest part of the install was threading in the new bolts when putting the seat back in, since the bolts are at an angle, which made installing them with the spacers somewhat difficult. I ended up putting a small tear in the front right of the seat when installing them.
Ecky, that's really quite an ingenious location for a sub, while keeping the spare tire! I like it! Is that still your current setup? What sub is it? Any issues with rattling in the rear?
I may add some rear speakers next year - with my rear design the biggest I can go with would be 5x7s if I want any kind of depth behind them. But for the price they would only add a small benefit, and I would then need an adapter for the sub since I wouldn't be able to tap into the rear speaker wires anymore. Maybe next year.