Yes to all 3 at +12. Although the Low Pass on the Sub I set to the lowest level which is 40 hz. With the R700’s I really don’t even need a sub and I should disconnect it.
Well definitely move the trims back to 0, or wherever they were calibrated to. At +12, that sub channel is likely being overdriven and clipped. Not good.
Not needing a sub? Well there’s a couple layers here. Respectfully, the Klipsch sub is very entry level. Its listed low end response is 30hz. The r700’s is 38hz. So if this is a mainly music system, and depending on the music style, you may not need one. But Ime, subwoofers just add something that speakers cannot. True full range speakers can be an exception, but are very expensive, and imo even most of them can benefit from subwoofers. That would largely be because normally the best place acoustically for subs, is not the best place for speakers. So, it kind of depends. Investing in power to drive them properly is also expensive.
If this is a movie system, imo, a subwoofer upgrade is absolutely in order.