Need advice for recording in a multi use non alterable space

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middlechamber
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Joined: Sun Oct 20, 2019 2:06 pm
Location: Seattle Washington
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Need advice for recording in a multi use non alterable space

Post by middlechamber »

Evening (from here in Seattle). I am just setting up a recording space in an active Masonic lodge. The room is big and my primary use will be to record acoustic (mostly classical) music. Biggest caveat, I cannot alter the space, nor install panels on the walls, etc. Everything must be floor standing or hung from stands or truss type setup. It also needs to be relatively light weight and storable out of sight. Its a really cool room with great character (visually). Its surprisingly quiet, and the location is tops - down the street from University of Washington.

Here is what I've got for measurements (close but might be an inch or so off).
Length = 55ft. (however there is a 12-15' wide alcove on one end of the length creating three different length dimensions of 53-58ft.
Width = 38ft.
Height = 13ft. standard institutional type drop ceiling with assumed original plaster ceiling 1-2ft above.

The room is fully carpeted. 3 walls are brick, likely covered with plaster, then canvas with historic murals painted on the walls (which is one reason I cannot touch the walls). Fourth wall is interior wood frame also likely plaster finished with painted murals on canvas covering.
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I was originally concerned with a very strong flutter echo so I built (10) 6ft x 4ft moveable panels using 1" OC 703. The panels are backed with 1/8" sheets of plywood. Ive spent a little time positioning the panels and listening while a pianist played a 7'4" grand piano. With the panels the room is too absorbed and lacks any vibrancy. The sound was also unclear in the mid frequency range. Ive been advised to create slat style diffusers on plywood sheets. The diffusion pattern is legit and I can build these:
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Ive also been advised to treat the low end first. Treating the corners with 4" 4'x8' of 703FRK could be done as long as the frames aren't too heavy to move.

Basic questions are where to go next? Can I/ should I alter the 10 absorbing panels Ive made turning them into membrane mid/bass absorbers (if this is possible)? Should I build diffusers or start with treating the low end? I don't have a large budget yet, so looking in the $1000 range to start not including the $700 on panels Ive already made. Thanks for any input.

**Edit** I forgot to mention the room is located on a second floor. It is built on 2x12 joists 16" on center. One beam runs the length of the floor about 12' away from the wall.
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**added** pics of the 10 absorbing panels I mention above. Im curious about modifying these to make a version of the panel absorbers viewed under the low frequencies tab on John's website. If I build surround boxes of varying depths (3-6"), then attach and seal the frames Ive already built inside the surround box, and then attach and seal the back of the surround box with a 1/2" sheet of plywood (or not) what would I accomplish? I only suggest sealing the back of then boxes because I cannot attach them to a wall.