@David Minarik posted:Foam is the worst thing you can put under your track.
Hold a piece in one hand and twap it with your finger. It is EXTREMELY resonant!
Lay that piece on a table (glued to it or not) and tap it. NOT THE SAME. Hold homasote to ear and tap. Lay on table and tap NOT THE SAME. I use 1" foam on top of 1/2 inch plywood and BALLAST the rack. NOT SOUND PROBLEMS! I also have a table with Homasote on it with unballasted track. Sound is LOUDER! With foam if I want a tree here stick it in if not pull out and move. NOT SO with homasote. Everybody is different and a huge amount that comes into play is how you are fastening the track and what you are doing on top of the foam. Don't forget how you placed whatever on top of the framing. Personally I like foam. I have no problems with sound or screws being screwed into the foam. JUST don't overtighten which is what everyone including me tends to do. I would challenge anyone to listen in my train room for track noise vs talking or train sound noise (non Track). As I said I have both so I can compare in real life not with meters or personal preference.
Curtis
