I used to not bother with EQ at all but now I find it very helpful to tune a particular track, genre of music, artist, recording, etc. to my liking based on the headphone I’m using or if I’m driving speakers. My MO used to be to keep everything flat at all times and not touch the EQ for “purity” sake but I don’t think that’s been helpful to what I wanted to hear and enjoy.
As it is often the case with any signal processing, I believe using EQ judiciously while listening carefully as you make the tweaks is the way to go. Everyone hears things differently and I have my own particular “tuning”, “voicing” or “tonality” that I’m going for while understanding that there are some inherent things that cannot be changed radically on a particular headphone or other gear. Well, I guess one could but then, doing so would most likely defeat the purpose of using that particular headphone or gear and/or produce rather undesirable results.
I found that I do need to apply some EQ treatments to both the SR1a and the LCD-4 but we are talking very narrow range of bands with 1~3 dB boost or attenuation. I’m fine using the Audirvana+ with the AUGraphicEQ 31-band Graphic EQ and I also have a free simple SONEQ parametric EQ if I want to zone in on a few specific frequency bands that the graphic EQ doesn’t cover. But that’s rare. I don’t want the EQ’ing process to ruin the listening pleasure experience with endless twiddling and going back and forth to decide what sounds the best. That can drive one crazy.
I think EQ is a good thing for one to familiarize with and, based on the headphones and/or amps you are using, use sparingly to boost the bass a bit for a little more slam, smoothen out the high-mids in the vocals, add a sprinkling of high treble for some more sparkle in the overall sound or a little more detail, add some body in the low-mids for warmth, etc. That’s all I use it for and I’ve come to see the EQ as a valuable tool to enhance the listening experience. I certainly would not recommend using the EQ to “fix” what one would consider to be a problem in the signal chain or the gear.