If you have the opportunity to build a room, and you have the space, make the room as big as your budgeT and physical constraints will allow. I am in a dual purpose custom built listening room that is used mainly for audio. But, wife wanted movies in the cavern, so I had to accommodate the home theater for the wife. I learned noise mitigation techniques in the Army and incorporated that knowledge into the design. If your building out a room, then adding acoustical elements such as Roxul Safe and Sound sound insulation in the walls, and perhaps increasing drywall width, by doubling up, or buying Quietrock Sheetrock will aid in reducing noise from escaping the room. You can also get a company to spray foam the joists in the ceiling of your room to further reduce noise leakage. Generally speaking, it’s easier to tame a large rooms acoustical anomalies than a small room. It can be done, but the audio presentation will be vastly different in a smaller space. If your room is a dual purpose room like mine, move the AV rack out of the room to free up space and reduce heat.