Final (hopefully) entire real wall. Ceiling soffits added above 8' slotted polys, hump reduced to 7 1/4" inches, my small mastering desk, electric outlets on rear wall (my recommended location next to couch, and also the location you mentioned, in the middle of the wall aprox.):
Frank--S367--Rear-slotted-polys-withsoffit-and-outlets-01.jpg
Frank--S367--Rear-slotted-polys-withsoffit-and-outlets-02.jpg
Details of soffit box and spacers:
Frank--S367--Rear-slotted-polys-withsoffit-and-outlets-03.jpg
Spacer shape, high res, with dimensions:
Frank--S367--Rear-slotted-polys-withsoffit-and-outlets-04--Spacer-curve.jpg
Frank--S367--Rear-slotted-polys-withsoffit-and-outlets-04--Spacer-curve-B.jpg
Frank--S367--Rear-slotted-polys-withsoffit-and-outlets-04--Spacer-curve-C.jpg
(Click on each of the above three for the full high-res image)
It's far easier to do the slat spacing in millimeters, as it works out to whole numbers. In Imperial, you'd have to be figuring things in 1/64 and 1/128 to make it work! I'm sure you have a metric tape measure?
SLATS: All slats are 4 1/2" wide, 3/4" thick, and routed to put a 1/2" round edge on both sides.
SPACERS: Make seven spacers for each side, and set them 16" OC, starting with the first one flat on the floor. The soffit sits directly on top of the top spacer, and runs 15" up to the ceiling. The spacers must be sealed to the rear of the stud bays! Not shown in the above diagram. These are tuned devices, so they do need to be sealed. Probably the easiest is to add extra framing members at the right locations, between the studs, so you get a flat front surface, (pull the insulation first...), and caulk it all up nice and tight, to the studs and the sheathing. (Then put the insulation back into the bays....)
INSULATION: You will need 1" of medium density fiberglass insulation directly behind the slats, just like you did with the "monster" devices in the rear corner. Held in place with chicken wire, beads of glue, or whatever you feel like. It needs to be more dense this time: OC-703 would be good, or even OC-705 if you can get it. But 1" thickness is what we need here. No thicker than that. Pink fluffy is too light.
SOFFIT: Wood dimensions not critical, but I did make them the same size as the slats on the rear wall (updated!!!! please note!), to match visually. No need to seal the soffit: it's just pure porous absorption bass trapping. Fill the soffit completely with insulation: whatever you have on hand. Not critical what you put in there: it can be a mix of any scrap insulation pieces you happen to have, or pink fluffy, or mineral wool, or fiberglass... anything is fine. But do put 1 mil plastic across the front before you put the fabric on.
REW TESTS: Do regular REW tests as you are putting up the slats, if you can. There's 15 slats on each side, so maybe do them in groups of 3 then a REW test, so we have lots of data to see how things are going. Or groups of 5 if you get bored doing so many tests....
That should keep you busy for a few hours!
- Stuart -
. Occupational hazard in this case. perhaps I'll throw it into the soffit.
I do see that some of the slats won't have very adequate backing if the ribs aren't deeper.
