You must correct those RS meters. Here are the correction values for the data points you have (all positive): 0,0,0.1,0.2,0.3,0.5,0.8,1.3,2,3,4.4. So you are actually down 7.6dB at 25 which is good. However, rooms will always improve the bass extension of speakers compared to what you will get anechoic (manufacturer's spec). That is about right for a speaker of that size in that size room. My 926s are only 1dB down at 20 in my smallish 14x13 room.
Your gear strikes me as a great combination. You have put some thought into and it shows. But the Cary has enough power?