Haven't had subwoofers since my dual 12" Rockford Fosgate Punch 500's back in 2004. I sold that setup for a set of rims and haven't invested in sound systems for any of my cars since.

That being said, BSW (bavsound.com) one of our forums sponsors, sells a very clean factory upgrade Subwoofer kit, and upgraded plug and play speaker kits for our cars if you are into subtle upgrades and improved sound, but not audio show worthy.

I think the sub kit sold by BSW is an 8" if memory serves correct. If I ever blow my speakers I'll be going with BSW replacements for my DSP equipped X.

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2018 Ram 2500 6.7L Cummins 68RFE
19k miles -Bright White/Black - Big Horn Sport - Crew Cab Short Bed
2013 X5 35D (CEO's) - Born on 5/17/2013 -
82k miles - Alpine White/Cinnamon Brown/Premium Pkg, Sport Activity/Premium Pkg and Sound/20" Style 214/Running Boards