Curious question: Is this dBA or dBC, and 'fast' or 'slow' response?
Still at download default settings, I've not had time to experiment.
Weighting is set for Flat with option for A or C.
Response is set for Impulse with options for fast or slow.
Level type is set for LP with option for Leq.
For comparison I just checked my listening / living room and got 39-41 DB.