Hi, I have a full Klipsch setup with RP8060FA II fronts, RP504 C II center and RP500M II surrounds.
With the 8060 Fronts I would bennefit the most of a sub around 20Hz.
And for sure I wanted a Klipsch subwoofer, but started to compare Klipsch with BK, SVS and XTC, and it will not be near these brands.
If I take a SVS SB1000 Pro it will do near the specs of the SPL 150, but less money, (far) less size, a nice app.
Also BK (even cheaper then SVS) and XTC will do a better output in a smaller box.
But I want to looks of Klipsch, the R-121SW will do around 28Hz, just a few HZ below the 8060, looks are ok, price is ok, but specs........😒