Re: Old FRC Controllers (Pre-NI)
The secret to isolation is mass. A door between the two areas needs to have mass to be effective. You can use an insulated steel door but it won't be as effective as a studio door which often has a layer of lead built into the door to add mass. Any studio door must have seals all the way around. Magnetic seals work well for top and sides and a strong drop seal for the bottom can be obtained from McMaster if used with a well designed threshold for sealing the floor. The High density or MDF walls should be two layers. Mount one layer horizontal and one vertical and insure that seams do not occur in both layers at the same spot. Small holes between areas sacrifice all the work you will do making heavy walls so be ready with good acoustic caulk. You want non-hardening, butyl rubber caulk that will stay flexible on parts that move like the door frame and window. Leakage between the two rooms will end up on track including the delayed program and your voices.
In order of preference for studio wall construction is solid concrete, solid concrete block, filled concrete block (sand or some other high mass material), concrete block, HDF or MDF multiple layers with separate or staggered studs, multiple layers of drywall, single layer of drywall both sides.
You can use the best techniques in the world but if you are starting in a bad space to begin with, all the money will be wasted. i.e., is the studio next to a mechanical shop or HVAC location or some other high noise environment? Is it on an outside wall with a train running by every day or is it near an airport? Is it next to the power vault? Is it under a hallway or main entrance with a lot of foot traffic above? Is it next to an elevator shaft or loading dock? I have seen people spend millions of dollars building a studio only to find out they have built over a rock formation that conducts all the traffic vibration from a freeway more than a mile away. Our school once was considering a million dollar renovation to their production theater because it was too noisey. A simple on site inspection turned up, an incorrectly installed chilled water pipe, a failed vibration isolator on an air handler that caused the flex duct joint to fail as well. The result was all the noise in the mechanical equipment was being conducted directly into the theater wall and the whole wall became a transmitter. Remember that noise traveling through a structure has very little attenuation and it travels faster through the structure than it does through air. Some problems can only be fixed by building a room within a room and isolating the inside room from the building with vibration isolators.
The walls can be separated by more than an inch and using a storage area is a great way to isolate the two wall. However, items in the storage area cannot touch both walls. The whole idea between the staggered stud design is that there can be no conduction path for energy striking one wall from being transmitted to the other wall. Russ Berger once showed me a studio wall design that was compromised by the construction guys throwing their pop cans down between the walls during lunch.
If this is your design, then two doors will be needed. If you can design the space so that the doors are not directly opposite each other, that would make the lighter steel doors perform better. How would you handle sight line between the two spaces? Do you care? We have no windows in any of our control spaces.
Last edited by Al Skierkiewicz : 05-02-2010 at 09:53 AM.