I recently found out from Dr. Hsu that there are a few Dolby Digital models that actually don't have bass management in 2 channel mode or the SMALL speaker setting
! I always thought all Dolby Digital receivers provided this functionality. I know that the Sony, Denon, and Onkyo units I've seen DO have it, and would assume that major brands like Panasonic do also.
I'm not sure about the NAD--you would have to ask the makers. I've was told by Dr. Hsu that even some Marantz units, including their expensive ones, don't have the bass management in 2 channel mode.