This is the classic study done in the 50's regarding perceived loudness in relation to frequencies. I think this justifies tone controls.
http://www.moultonlabs.com/gallery/image_full/79/
Now, this begs the question of how to do it. "Spatial computer" has begun to build into the computer the software to adjust the sound to your room. It is a beginning. And it may be the future. In the meantime, having some adjustment to compensate for loudness or poor recordings is reasonable. In a perfect world we have a perfect room with perfect material and is played back through a perfect system. Now, back to reality!
http://www.moultonlabs.com/gallery/image_full/79/
Now, this begs the question of how to do it. "Spatial computer" has begun to build into the computer the software to adjust the sound to your room. It is a beginning. And it may be the future. In the meantime, having some adjustment to compensate for loudness or poor recordings is reasonable. In a perfect world we have a perfect room with perfect material and is played back through a perfect system. Now, back to reality!

