Years ago I had a rather pricey (for those days) equalizer referred to as a SCAN-ALYZER/EQ
Now with a whole new system, I purchased the newly introduced Schitt Lokius a few months ago. I find it works very well for fine tuning. This may be because I wanted to add a just touch more treble emphasis to my soft dome tweeters, versus compensate for any weakness in the electronics. For me it is basically set and forget, same adjustment for all music, not adjusted individually for any particular song or album.
As wolf mentioned:
No clue how they managed this but you can flip it on and off, take it out for comparison, pour hot lava on it, subject it to quantum magnetic hypersnot....whatever...and it is signalus non interuptus el mundo.
I wish I had learned to speak Spanish.