At first I had quite a similar setting as you did but I wanted the least adjustment possible because I don't really want to change the sound signature.
My current EQ setting for DN-2000:
@ 80hz / +1db / Q=1.5
@450hz / -2db / Q=1.5
What I'm after is a tighter/thumpier bass from the DN-2000. I find the settings above meet my requirements without changing the sound signature much.
It's still not at the same quantity as the H-300 but the quality is quite close as far as detail and clarity.
I'll post my EQ settings for H-300 in the morning. I'm at work right now and I don't have access to my EQ settings.
Your C5 with bass boost on doesn't improve the bass for DN2K as much as EQing?