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
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
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.
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
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
drawing shows how to construct your windows.
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.
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.
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.
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.
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.
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.
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.
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.
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.)