Soundproofing a Recording studio

There are a lot of different websites and blogs out there that have different opinions on how to best soundproof a home or commercial recording studio. The type and quality of the recordings will determine how much soundproofing you will need to have to achieve the best quality recordings in the studio. There are a lot of factors to consider when constructing a professional grade-recording studio.
 
  In a commercial area where there are city and traffic noises that can penetrate normal walls, you might set a goal of at least 56 STC for the walls and ceilings of the studio. Generally you will be able to find studio doors and windows that will meet the 56 STC rating. A recording studio that has a 56 STC rating would be what most producers would consider a professional grade studio where any professional musician or band could record.

  Most of the big recording studios have an STC rating of up to 80 STC, but these studios cost Millions of dollars to build and most of us don't have that kind of money to put into a studio.
 When constructing a commercial or even a home studio the first this to consider is the walls and the ceiling areas. What can be done to soundproof these areas to provide the best soundproofing environment for recording? If you are working with open Joists and studs, that I would recommend placing rock wool batt insulations into the wall and ceiling cavities. In a ceiling application, the rock wool would be adhered to the sub floor or the roof area between the ceiling joists. Rock wool both blocks and absorbs noise and actually helps to dampen the structural members in a wall or ceiling assembly. In a ceiling application, once you have the rock wool installed in the cavities, it would be a good idea to fill the rest of the cavity with a standard fiberglass R-19 or R-30 batt insulation.

  The next step would be to adhere a layer of 1 Lb mass loaded vinyl to the bottom face of the joists and the studs on the walls. The MLV would be stapled or nailed to the wood studs or screwed to steel studs with self-tapping sheet metal screws. It is recommended that you over lap the seams by at least 1/2 of an inch and the caulk the over lap as well as the perimeter with an acoustical caulk. Once the MLV membrane is sealed, you come to a crossroads. You have the choice of layering over the MLV with a layer of 5/8" drywall of a layer of 5/8" Hardi Board (concrete board) and then taping mudding and painting the drywall or you could add a second layer of drywall with the Green Glue visco elastic damping compound applied to it. The Green Glue would damp both layer of drywall and would prevent the drywall from being able to transmit sound. This would provide you with a very secure and soundproof wall and ceiling assembly.

 Lastly, if you wanted the best soundproofing possible, you might consider floating the walls and ceiling on sound clips and furring channels. This is a very effective method of soundproofing which isolates the walls and the ceiling from the frame structure as well as from each other. It would take too long to explain this application in one article, but please feel free to e-mail me and I will be able to give you that particulars on using sound clips and furring channels.
 
Other things to consider when building a recording studio are the windows and doors that you will need for your control room to live room and for the actual entrance into the studio itself. I will talk about studio doors and windows in subsequent articles. I will also discuss floated studio floors at a later time. Thanks for reading and learning with me. Soundproof Bob!