i say open because I have already removed the outside grills and foam and am running without that stuff. Even then the soundstage is not as wide as the M1060. So i did a mod to fix it. I call this the “Kitchen Drawer” mod because you take that stuff they sell in the grocery stores to line kitchen drawers and put it around the metal case. Idea is to absorb and diffuse reflection points. With this mod the m1060c now has a bigger stage than the M1060 even modded as I have it. Depth is probably the same but because the stage is wider it seems depth is a bit less. Its stretched enough that there is now black between instruments. Here are some picts https://postimg.cc/ZC9WkMZN Chose this stuff because it is cheap, readily available, easy to work with, and because it is spongy and shaped should both diffuse and absorb. For the ocd looks people do note i dont care how my cans look. Sound is everything. You may be able to find this stuff in black. The 3 black strips are damping sheets like dynamat and the gooey stuff painted on most of the metal is C37 lacquer. I left the horizontal traces un painted in case I want to add damping.