My SMS-1 is level matched at 80db with my speakers, but the volume of the SMS-1 is under 10 out of 100.

Which does not seem right.
What db does most users, use to level match??

My McIntosh C46 (2 channel pre) does not have any x-over/ bass control or sub outs. So its all going into the SMS-1 with JL subs.

Sub sounds seems light, when level matched for music only. If I turn the SMS-1 up, will not the SMS-1 be set high compared to my speakers?
Dunno..