"On the Sony TA-E9000ES, it was ~-50 dB for CDs, and ~-30 dB for DVDs. All cals around 0 dB."

So zero would be reference? That would mean you listened to DVD's whose maximum volume was 75 db (30 db below reference). Dialogue would be around 55db. Ambient noise in a room around 45db. I take it you do a lot of late night listening?