I gave it a shot. The mid was extremely easy to adjust. The high was much harder to get right but I got it. And my low can't be adjusted because I can't get distortion at the required sound level (infinity 6X9's, no external amplifier), but that's ok because I like the bass tunred down anyways. Highs and lows are now adjusted as close as possible to reproducing the music as it was recorded, according to the article. And it sounds really good, so it was worth the time IMO.

Distortion at volume level 32 / 50, so adjustments were made at volume level 30.

High is at 7 (-10 to 10)
Mid is at -8