Originally Posted by Roger Dressler
"there are often physical conditions (such as room size or dimension) beyond the control of the engineer"
Sure, but it's a leap to conclude from that comment that "If there is no intrinsically correct way to position speakers in a production studio, then there’s no basis to conclude they should be at ear level at home."
There is indeed
an intrinsically correct way to position speakers. The reason to have them at ear level is to ensure a flat response by being on-axis with the tweeters. It's not like any random height will give the same result. The higher the speakers are for a given distance from your ears, the worse the HF response will be. At least for the normal box speakers that most people use.
Did you read in there something saying the room should be dead?
No, that's my personal opinion. Small untreated rooms sound small because of all the reflections from nearby surfaces. When the walls and ceiling are near, the reflections are strong and also early. So by minimizing those reflections the room is made to sound larger than it really is. This is a Good Thing IMO.
There should be as much diffusion as a budget will allow.
I totally agree with that! Unfortunately, good diffusion costs a lot more than good absorption, whether one buys commercials diffusors or makes their own. For this reason I often suggest absorption in smaller rooms, and at reflection points I find absorption to be superior to diffusion. But there are many other places in a listening room where diffusion is great, such as the rear wall behind the listeners.