Bought my wife a new SUV (2015 Lexus NX200T) and I inherit the 2014 Acura RDX.
RDX has the tech package which includes the ELS audio system. Sounds fine for most music, but I have always felt the bass was lacking. Stock woofer is either an 8 or a 10 in a small enclosure on the right side of the hatchback. No matter the EQ settings it just never delivered what I wanted.
In my last daily driver (2009 Ford Fusion) I had installed a small bass package including a class D Clarion XC1120 mono sub amp. I pulled that out of the car before trading it in.
Installed in the RDX in the center console right with the stock amp. Bass knob installed in a blank spot left of the steering wheel. A nice low power setup (210wpc at 4 ohms).
JL audio ported 8 inch sub. Tiny. REALLY tiny to me - about 1/3 my old sealed 12 box, and at least 1/8th of my old ported 12 box from years ago. The dimensions on this box are 19x11x5 (roughly).
Bolted the sub to the rear of the back seat and all set.
Great in the car bass. Not block booming outside the car, just a rich, tuneful articulate bottom end.
The bass knob I love - can dial it down or flesh out music exactly as I want to.
Good fun for about USD$250.

