As far as the window goes - the maximum isolation would be to keep the glas parallel and as close to the face of drywall as is possible........ BUT
but what I have is an 8 x 6 area. Nothing is up at this point except the interior wall portion which seperates the booth from the main room.
SG- Rods answer notwithstanding, this is assuming there are no other flanking paths...such as common HVAC ducts feeding adjacent spaces, or a common cieling with a TL less than the wall, or common sidewalls that continue past the partition wall and were shiethed prior to building the partition wall, not to mention possibly a WOOD FRAMED FLOOR that is common to both rooms.
Its difficult to envision the state of your construction at this point or even the plan. Remember WEAK LINKS. You haven't even mentioned a door into this area you refer to as a booth. It too would need to match the transmission loss of the surrounding assembly or your wasting your time and money. Why spend the money putting in two layers of drywall, two leafs of heavy glass, and then penetrate the partition with a HOLLOW CORE DOOR!
Is this "8'x6'' area the booth? Are both spaces just studs at this point or are you partitioning off an area of a room that is already drywalled? What are you doing for ventilation once you partition off the space? Is there a door in the same wall as the window? These are a few questions that have a bearing on the successfull "isolation" via this partition.
Personally, and this isn't knocking Rods answers, but I feel it's importand to add, without knowing the whole ball of wax regarding existing construction,
no one can properly assess whether its worth this added expense and time, when in fact it may be a lesson in hindsight and poor judgement by virtue of existing or planned components that may negate this added mass. Maybe you can tell us a bit more about the state of existing construction and other things such as your plan for ventilation/HVAC before you commence.
fitZ