Do you could do it for free in the Digital domain, dont know what is your source, but my old Sony SCD1 have 4 different Freq Range shapes on the PCM(CD) domain.
I dont know the current DACs and PC players but surely they may have much more different Freq shapes to feed the amp/preamp and please the music lover.
The software side is for sure where tone controls have been heading. I haven't found any yet that do it for me. Hardware wise I have found 3 at different price points that deliver. The loki mini($150), faux fairchild 627($1k) and my current sony se-p900($1750 and good luck finding one). I went through about 20 eq's to come up with that 3 and I have tried a good dozen software eq's.
Sadly this is an area of audio that has been neglected for a long time. I don't blame you for thinking they are a bad idea because most eq's were poor quality when I tested them. A few of them were quite amazing and kind of once you hear it done right there's not much going back.