Hello all…I just got done building my first vocal booth. The booth is 4 X 6 and 10 ft. high. I only built two walls because I used the corner of the room as my other two walls. I covered the exterior of the booth with carpet. I built the booth using plywood and 2 X 4’s. For the door, I just cut out 2ft from one of the sides and made that the door. Yeah I know, not the best thing to do..but hey! Now I don’t know what to do about the treatment on the inside of the booth. Can you all tell me what type of foam or insulation to use for the interior? I need something cost effective. I was thinking of maybe putting some type of insulation on the inside wall and covering it with plywood on the inside of the booth. And then putting some type of foam on top of that to complete it. But as you can see, I am a newbie. I mean, is it necessary to close in the walls from the inside or is it best to just put the foam up on the walls in the inside. So can some of you give me some cost effective ways to treat the inside of the booth. Also, I need to know how to treat the roof of the booth and what to do about ventilation. So help!!!!! Asap. I want to take care of this immediately. Thanks a lot my fellow musicians…peace.