Walter,
I checked out Rotel's website and downloaded your
owner's manual. I don't see any mention of those details. The tone controls provide +/- 8 dB at 100 Hz and 10 kHz. I can't remember which speakers you have, but perhaps that explains what you are hearing on them? Perhaps, but probably not.
BTW, if you don't know about it, there is a software update for the RSP 1066 available from Rotel at this link
here. You can read what it does in PDF format at this link
here.
Adam