I think I read that Dynamic EQ sounds like the old loudness button from years back. It is supposed to keep things dynamic ie. bass and highs boosted, when the volume is low, which is when you typically loose those frequencies, are harder to hear, on most systems.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70