What does those numbers in the y-axis (vertical line) means? The ones with the minus sign (0,-10,-20,-30,-40,-50,-60)?     Thank You!

I am looking for my first IEM that will match the sound signature I am looking for. Is it better to buy a neutral IEM and use the EQ to adjust it to the music or is it better to buy an IEM that has a sound signature that fits my music?   Thank You

I am ambivalent between these three IEMs, this will be my first pair of IEM and I thought you guys would help me choose one.   I have read numerous reviews and comparisons between these three IEMs from different sources, but the more I read the more indecisive I become. I listen mostly to EDM...