Amp Question Please advise

You may have to sit closer if you want low level detail in a room that big. (and more power with a detailed amp won't hurt.)

If everything's OK with room and speakers I'd suspect source having not enough output level to feed Denon.

changing the amp won`t help @ low levels. Change the spkrs. if you can. A fair # of spkrs. sound like sh*t @ low levels.

I'm not sure about the Paradigm 40's but when I went from 140 watts to 300 watts (into 4ohms) with my dynaudio 1.8s, I noticed that I had real bass at lower levels, and didn't need to be cranked as much to get a coherent soundstage. I'd guess around 150 solid state watts (into 8ohms) from a quality amp (no mass market recievers).

I put up with that from my B&W N804s for a year ... increased energy brought out why they were such outstanding speakers, but a morning read with some nice background music was IMPOSSIBLE ... far too flat and lifeless. Give them juice and ... ZOWIE!!! Shifted to Tyler Taylos w/sub and didn't regret it.