I fully understand the whole 'core' thing. HE-400 is very heavy on fundamental notes and lighter on harmonics. So a lot of the brass and strings will sound either 'calmed' or softer, while a lot of low brass and woodwinds will be very prominent in the mix. If you want more harmonics you can bump 3-5khz up 3db or so.
Or you can move the other bits around so that 1.5-5khz sounds relatively balanced, I found that just making that area louder and leaving everything else makes it sound erm... disjointed.... But if you make a curve so that area is relatively higher compared to default it seems to do the trick without sounding "wrong"... to me anyway.