Compensation curves like the Harman one are a way to match measurements up to what we hear. They're designed to emulate the effects a person's outer ear and body have on natural sound waves (or sound waves from speakers) that headphones bypass.
What I did is basically uncover my own personal compensation curve. It's the same basic premise.
Equalizer APO is a parametric EQ that ties right into your sound card drivers. Problem is, it doesn't have a graphical UI so it's very hard to use. You can get around that like I did by using a parametric EQ with a GUI to build the EQ, then figure out the Q values and put them into Equalizer APO's config file. Much easier though is to use
Peace, an addon graphic EQ GUI for Equalizer APO with a lot of customizations.
Here's what my config file looks like if you're curious. I don't recommend using it because you don't have my headphones or my ears.