DIY Slot Resonators

Hey guys, I'm about to purchase my material for my slot resonators. I have two questions and some general info for other people going to build these. (Pics to follow when I start.) My main post is here: http://www.johnlsayers.com/phpBB2/viewt ... highlight= I've attached a skp file for approximate layout of the resonators... it's crude, and i've borrowed the resonators from one of Johns drawings :wink: I'm planning on building 8 broadband resonators. I am building them as stand-alone, not attached to the wall (I will need to remove them in a few years). So I intend on closing and sealing the back, psuedo- random order of slat and slot sizes (2,3,4,6" slats, 1/8-1/2" slots) and I will put in several bulkheads, to break up the internal spaces. 4- 4'x8' sawtooth for the control room, 2- 4'x8', 4- 4'x4' "portable" resonators for the tracking room. (to be used like gobos) Material Oak/Birch Ply 4'x8'x3/4" 8@$40 (Lowes) $400 Back panels ???? 10@23 (lowes) $230 2x3 studs 35 @$2 (Lowes) $64 Mineral Wool 720@ .44 (SPI) $316 Black 50"burlap 28yd@4.50 (FabricLand -net) $126 Landscape fabric 22yd@ (lowes) $50 Nails...etc... misc... $25 Questions: 1.) Should I use 1/4" OSB or plywood for the back of the resonator or 3/4" MDF ? I've seen both on the forums here. (a few posts steve has recommended the mdf, and the SAE site has 1/4" in the build diagram. 2.) Should I use a mixture of the 8pcf mineral wool and the OC703 or does it not matter? 3.) I've also seen both plans for a single layer about 1" behind the slots... and I've seen two layers of insulation, one against the slots (again I've seen it against the slats and some are 1" recessed) and then another layer of insulation against the rear of the cavity. Any direction, and info as to why each material or method is chosen would be great! Thanks kevin