Arc Ultra owner - is adding a sub overkill?

I have an Arc Ultra (recently upgraded from Beam) + two One SL's as surrounds. It sounds great. Bass is actually fine for regular TV viewing with the current setup. But, it doesn't give you that crazy rumble that is sometimes nice to have for movie watching. I'm considering adding a sub, buy my question is....would it be too much as an everyday add to the set? My TV area, unfortunately, isn't exclusive to home theater. Our first floor living area is an open concept. Can you dial down the sub for times when you don't want all that bass? Appreciate everyone's thoughts!