There are some general guidance documents on setting up studio monitoring systems for level. Many adopt Bob Katz* approach (1). I came across the following link which is a bit easier to follow (2).
The size of the room is very important, since the -20dB point will need to be at somewhere between 75dB for a smallish room (UK lounge :-) ) to 85dB for a big room which is a big range difference.
* Well known mastering engineer.
When you have a system setup like this, it is surprising how many recordings "snap into focus! In terms of loudness they sound right. Obviously, most systems can go louder, but I've observed that when doing so, although everything is louder, it seems less right. Bear in mind, that domestically available recordings are mixed for domestic consumption, not PA levels of energy. I feel that a system that sounds right at PA levels is probably not right.
(1) https://www.digido.com/portfolio-item/level-practices-part-1/ and https://www.digido.com/portfolio-item/level-practices-part-2/
(2) https://www.gearslutz.com/board/mastering-forum/1024714-depth-bob-katz-k-system-tutorial.html
The size of the room is very important, since the -20dB point will need to be at somewhere between 75dB for a smallish room (UK lounge :-) ) to 85dB for a big room which is a big range difference.
* Well known mastering engineer.
When you have a system setup like this, it is surprising how many recordings "snap into focus! In terms of loudness they sound right. Obviously, most systems can go louder, but I've observed that when doing so, although everything is louder, it seems less right. Bear in mind, that domestically available recordings are mixed for domestic consumption, not PA levels of energy. I feel that a system that sounds right at PA levels is probably not right.
(1) https://www.digido.com/portfolio-item/level-practices-part-1/ and https://www.digido.com/portfolio-item/level-practices-part-2/
(2) https://www.gearslutz.com/board/mastering-forum/1024714-depth-bob-katz-k-system-tutorial.html