You shouldn't have to touch the bass control on the Nad at all to get significant output from the EP500. Are you adjusting the EP500's volume control? Set it at around the 11 o'clock position to start anad the volume on the NAD to about halfway. Play a well recorded rock or jazz CD or LP with good electric or acoustic bass.

You ARE using the speaker-level outputs in to the EP500, right? (not the RCA jack pre-outs).
Where do you have the EP500's crossover control set?

Alan Lofft,
Axiom Resident Expert (Retired)