4' X 4'

Where? They should be placed at the back of the room evenly
dispersed first and foremost, with a few along the side walls at a wider
spacing for total reflection coverage. Portable Acoustics units can be
placed across the back corners of the room to get twice the low
frequency out of the room per square foot as when they are placed in
front of the flat wall sections.

How many? Three absorbers and three stands come in a box and these
are made to use the same formula as our permanently attached wall 
system ‘Black Hole Acoustics’tm  mounted absorbers. One box for a
small room, two boxes for a meeting room sized for 25 persons, three
boxes for a meeting room sized for 50 persons, four boxes for a meeting
room sized for 100 persons, and one box more for every 50 persons
after that. Remember, it’s the capacity of the room not how many are in it
at the time your treating for.

When? Right now! You’re wasting time on really bad and unintelligible
sound. You don’t need to any longer now that Acoustics in a Box’s
“Portable Acoustics System” is here!

One Box has three stands and three foldable absorbers in it for only
$675!! Yes we’ll sell you only one if you need just one for some reason
for only $250!
Easily Portable to the Location - Folds out from a small
box - Hangs on a high stand - controls a room for a time -
then back into the box and back into storage again!
  1" Acoustical Baffle Test

125Hz = .52    250Hz = .78
500Hz = 1.93  1000Hz = 1.95
2000 = 1.77    4000Hz = 1.68
               NRC 1.60