As an independent Foley Artist I work in many studios through out the New York area. In this one particular room the situation is anything but typical when it comes to Foley stages. Like many studios in New York City , when it was built, it was never intended to be a Foley Stage as much as it was a small booth to record voice over and ADR.
Most Foley stages will have several surfaces build right into the floor to connect the sound of the surface directly to the foundation or sub-floor of the building. This is almost counter intuitive to most construction practices in use today for building live recording rooms. A typically isolation room, is a room built with in a room to separate it from the rest of the world.
The problem is that in a Foley stage, the floor surfaces and pits are filled with various types of material like sand cement dirt etc. is everything. The solution that this studio came up with was to build a couple of 4’X4’wooden boxes to act as movable Foley pits. One is filled with cement and the other fitted with ceramic tile stuck in cement. In theory this could work but in the reality of Foley, it fails without mercy.
You see, the wood used in the construction of these boxes makes almost the same amount of sound as the cement in them. Not to mention that once we started moving them in and out of the room, the hardened cement began to break up and then they really started to sound like ass.
My solution was to bring in a 3’X4′ X 2″ thick slab of slate and another slab of marble. Both of these slabs sounded a world better than what was left of the “Box of Death” (the name that they got from the inters who had the honor of moving them in and out of the room).
Something was still wrong with the sound. In my initial go I placed the slabs on carpet to try to separate it from the hollow wood floor. My reasoning was sound but when I walked on the slate with hard shoes it began resonate like a sheet of diamond plate.
I trying a number of thing to get the slate to stop ringing including sand bags, blankets an intern standing on a corner and duct tape (My personal favorite material in the world). I was about to through in the towel when it came to me to just lay the slate down right on the wood floor . The engineer needed to run a hi pass filter at about 150hz to eliminate the low end rumble and the surface started to sound like a NYC sidewalk , as I like to say , We win.