Equalization

This is great info.
Being a Musician (50yers+) and have done some live sound.
I have also recorded in many studios over the years is the reason I asked the question.
Studios go to extremes to "Tune' their monitors to the room and the room itself.
I took an RIAA recording course at Intermedia Sound in Boston.
Famous for Recording Aerosmith's first Album and other well known artists like Donna summer and the cars.
The Room was actually built on Truck Shock absorbers.
Although I have plenty of Music and Audio experience the Hi End Hi Fi Purist world is intriguing.I am learning a whole new concept of listening to music.

Unfortunately there is also quite a bit of snake oil being peddled. As for room acoustics and equalization, including some useful links: https://forum.audiogon.com/discussions/room-acoustics-10

bstbomber,  I still remember that I had to constantly adjust my old inexpensive receiver's controls.  It was either too bassy, too veiled, too bright etc.  Almost every CD needed some adjustment.  Today, with better source, amp and speakers I don't need to adjust anything.  I also noticed that the cheapest boom boxes have all sorts of controls including graphic equalizers. There is a reason for that.  Tone controls don't improve transparency and don't come for free.  Same goes for balance control, (that I don't need).  I like to listen to music the way it was intended.

In the most expensive manner possible.

Snake oil is good for the hobby. 🐍 It greases the wheels of progress and makes everything run smoother. Obviously not everyone is on board the progress train and that’s OK. 🚂