B&W Nautilus 800.....where's the bass?

Is it a well known fact that these speakers lack bass? I just bought them used...two years old....and am very dissappointed in the low end. My CDM 9 NT rears have more bass than these. No kidding. Is this a known problem with this speaker, or could there be something wrong? Since the 9's and the 800's are playing at the same time on the same system I do not think there is any need to list the equipment, but I will just in case it matters.
Sunfire Theatre Grand 2 processor ( all speakers are set to large)
Denon 3910 CDP
Adcom 300 by 7 ( 800's are bi amped with four of the channels.....phase is correct)
speaker wire is 14 guage in a very thick outside jacket
Thanks for your help.