4 8 inch subs or 2 10 inch subs in 2018 F150?

I'd do the dual 10 solely because of protection of the speakers, now the quad setup with grilles.....

Sent from my HD1905 using Tapatalk

It's been my experience that the cone diameter of each speaker has a different signature (again just my own experiences). Sealed and ported boxes also have different characteristics.

10's are smallest size I use for "subs" although I use 8's for woofers. I have a pair in my front doors now. I definitely like option 2 in this situation. Let us know what you go with and how it sounds!

Subwoofer output is primarily driven by cone area (Sd) and excursion (Xmax) though power handling and sensitivity play a minor role as well. The quad 8” (SWR-8D4) subs win in cone area but only have 12mm of excursion. The dual 10” (R-W10D4) don’t have quite as much cone area but have much greater excursion at 20mm. The 10s also have greater power handling so can take a larger amp if you want. So for me, I’d take the 10” subs as you’ll get more bass output capability and the further you stay away from the output limit the less distortion/better sound quality you’ll get.

Do you know the internal volume, and port volume of that ported box? Ported boxes aren't as "universal" as sealed boxes, so depending on what that box is tuned to, you may not want to use it.