I'm sure no expert here, but I can only tell you to do what I'd do myself, and that is do some trials first. I'd start with neutral(or mid if there is no neutral) tone controls, see how that plays with the 2150, and adjust from there. As far as the volume level, max would likely be best.

What media player do you use ? WMP allows you to turn off any audio effects. I'd even try different software players, I'm sure they don't all sound the same.

I empathize with your problem here, I find it kind of ironic that digital music, which was supposed to simplify our musical lives ...... it has done anything but !