Hi all. There is a tiled nook next to our fireplace that is normally where you’d keep the fire wood. I made a sealed sub and have a glass shelf for my avr to sit on. I could either sit the glass on the sub box and use foam isolation pieces or I could install the shelf about an inch above the box. I know it’s not advisable to have a sub so close to the avr, but this is the space the wife gave me. Here’s a photo. Any suggestions on the best way to keep the sub from destroying the avr would be great.