Hello, I have done it and it works very well ... with two Roland (4w and 51d) and the compressor.
Make some walls (4) of gypsum board composed of: 13 mm gypsum board + "MAD4" heavy membrane + 13 mm gypsum board + "MAD4" heavy membrane + 15 mm gypsum board ... this for each side of the structure metal wall.
You anchor the ceiling by angles to these 4 walls using 15 mm gypsum board + MAD4 heavy membrane + 15 gypsum board + MAD4 heavy membrane + 15 mm gypsum board.
Then you have to paint walls and ceiling ... but they are smooth (due to dirt).
If you place a glass that is 4mm thick, an air chamber of 2 cm and another glass of 4 mm thick (and if possible, one glass is not perfectly parallel to the other).
The door is not placed one ... 2 doors are placed that are NOT parallel but in an "L" shape so that they leave a vestibule between the two ... it is important that the door frame has a closure in the ground area .
Then on the floor you place a high density foam type "Copopren" and on this a 20 mm thick wooden plank .... which will be where you step and support the furniture, machines, etc.
With this system I have managed to lower the 90 dBA inside the room with the compressor and the two mills operating at 28 dBA outside the room ... the PC is very comfortable
From this pot if you are comfortable, your neighbor will not hear anything.