Global Media Education - SAE Institute
Windows And Doors
Windows and doors require special construction because no matter how much you seal your walls if the windows and doors aren't built correctly your isolation will be ruined. The main thing with windows is that they must have the following features:
- Different Glass Thickness. It is essential that the two sheets of glass be different in thickness. I recommend that you put the thicker of the two panes on the control room side. The thicker the glass obviously the better the sound isolation plus the thicker glass has a lower resonate frequency. Unfortunately thick glass is expensive. I would suggest you try 8mm and 10mm glass. (5/16", 3/8"). Any thinner and you are going to start getting resonate frequencies from the glass and inadequate sound isolation.
- Angles. The two sheets of glass must be at an angle to each other else the two sheets will interact in a resonate sympathy and the sound reduction properties will be reduced. You can angle the glass as in the following drawing but don't forget that the glass can also be angled in the horizontal plane as well as the vertical plane.
- Silica Beads. Because the windows are sealed the cavity created is a different temperature and humidity than your rooms which are probably air conditioned. It is therefore possible for the glass to steam up as in your car but not quite as dramatically. It is therefore recommended that you purchase some silica beads ( like you get in a little sachet when you purchase a quality camera or the like) and put them in the cavity between the glass.
- Insulation. The cavity between the glass is like any space and will have a reverberant field so you must line around the cavity with insulation. The easiest way to do this is to cut sheets of fibreboard to the shapes and then glue thin fibreglass to it. Then you can wrap cloth around it for aesthetics and glue it into place. It is also a good idea to drill 25mm - 50mm (1" - 2") holes in the fibreboard in which you can put the silica beads.
The following drawing shows how to construct your windows.
Window Construction
Window Construction Detail
Doors
You can use two types of doors in a studio. Solid core doors or glass doors. Obviously if you wish to use glass doors the glass, like in the windows above, must be of a reasonable thickness to stop resonance. I'd suggest a minimum thickness of 8mm (5/16") yet obviously the thicker the better. Glass doors are good because they increase the communication factor which is important in a studio but if you are to use a two door sound lock you must have the doors at an angle to each other or you will get standing waves between them that will reduce isolation.
Hinged Doors
- Seals. As with windows once again correct sealing of doors is the main determinant that effects the sound isolation. Doors must be sealed all round and it is advisable to purchase proper commercially made door seals. There are a number of different manufacturers of door seals and I suggest you contact your local supplier. The most important seal is the one at the bottom of the door as it is the hardest seal to make. Some commercial manufacturers make a seal that has a spring loading so that when the door is closed a lever is compressed that causes a rubber seal to be forced downwards on to the door jam. When the door is opened the seal is lifted again.
- Thickness. It is recommended that you purchase solid core doors. If you wish to isolate you can clad the room side with extra timber that gives a nice finish and increases the effective sound isolation.
- Insulation. Like the window the two doors create a resonate cavity when closed so it is advisable to line the cavity and the doors with some insulation and cover with cloth.
Sealing Doors
You can purchase proprietary door seals that fit into the base of the door. The unit has a sprung button that when the door is closed forces a rubber seal down onto the door jam. When the door is opened the spring releases the seal.
Sliding Doors
I personally like sliding glass doors in studios because of the visual communication they afford. Like windows they can't be parallel so I always put them at an angle in the horizontal plane. (The vertical plane creates unbelievable problems with runners and seals.) Sliding doors can be made of either timber or aluminium.
- Seals. Naturally a glass sliding door will not have the sound isolation of a hinged door purely because of the construction complexity but if you use a quality door and discuss the seal problems with your local manufacturer you can come up with a pretty good seal.
- Thickness. I recommend you use at least 8mm (5/16") glass but here again the thicker the better but too thick makes the door extremely heavy to slide.
- Insulation. Once again the cavity between the doors must be lined with insulation to stop the reverberation within the cavity. The same method as in the window (i.e. cloth over fibreglass over fibreboard is the simplest system.)