I am an old audiophile coming back to the hobby. Why don't headphone amps and or Dac units come with an equalizer? Wouldn't that solve most of our Headphone paring problems? I had a Citation preamp in the old days with a nice equalizer built in. My new LCD-XC needs a little more bass so just hit the sliders. MyTh900 has a U shaped curve that you fix in a second.
I know that the equalizer dirties the signal to a certain degree, but versatility I think outweighs the lengths I see forum members go thru to optimize this amp to that headphone.
What am I missing? I need enlightenment!