Matching EQs using Curve EQ gets bad sounding result


I tried this exciting feature, “Matching EQs”, with the plug-in Curve EQ. I have been following several tutorials on youtube. When I try it out everything looks OK and the 2 curves ( “reference” and “apply to” ) look rather close. But when I press the button "Match Spectrums ", I get a curve with values as high as 9 db over the reference spectrum, but also some values as low as 9 db below. Of course, this does not sound good.

Can anyone please help ?

Okay I found out that music you match has to be very close. It works best if the instrumentation is total the same.