I believe you’re right about the analog inputs. Not much happens except volume control. Signal path is Oppo 105D analog out to Marantz 7706 pre-pro to Outlaw sub, which has a light indicating whether it’s active or in standby.Im not sure of your equipment, but in my experience most AVRs will not perform room correction or bass management from MCH analog inputs. They default to a pure direct mode. If your mains are not full range, some bass would be lost. Could this be what was happening?
That doesn’t say I think I was missing any bass. My fronts are Emotiva Stealth 8s, which go pretty low on their own. probably in the range of 30Hz useful.