“I’m using a pair of Event monitors in a small studio suite in my house. As the room is so small I would like to recess them into the wall so I can move my mixer forward and create more client space behind me. Before I cut holes in my walls, is there anything special I should know?”
This is something to avoid if you can. When you mount near field monitors such as this flush with a wall, the wall essentially becomes a giant baffle, which will radically change the sound of your speakers both in terms of tonality and stereo imaging. They just aren’t designed for soffit mounting.
However, if you must do this, there is a way to do it where you can minimize the problems. Cut the hole out so there is an extra foot or so of space all the way around where the monitor will sit. If possible use a speaker stand behind the wall, or use a lot of very thick foam to decouple the speaker from the wall. You can use some type of grill cloth to cover the giant-sized holes. Mechanically isolating the speaker from the wall and keeping the wall surfaces away from the front (baffle) of the speaker by at least a foot will greatly reduce acoustic anomalies that will detract from the accuracy of your monitor and help retain some of the soundstage in your listening. You are still better off with the speakers on stands out in the room, but this is a workable compromise.