Post by JBzen on 12/03/20 at 21:35:46
I purchased plans from Decware for the P1312 diffusers. Spending, at this point, about 50 hours building 40 of the units. To finish, the plan is to construct frames out of oak to make-up 6 assemblies of 6 units and 2 assemblies of 2 units.
Attaching the frame assemblies on the walls at first reflections points to minimize smear created by reflections of mid to high frequencies joining the direct frequencies at a rate that the ear processes as one, hopefully the sound stage will deepen, details will improve, and intimacy of the musical performance will be truer to the artist intend. My room is medium to small with splayed side walls. Placing each of the 6 unit assemblies at the first reflection points of the front/side walls and ceiling with the remaining 2 unit assemblies on the back wall should diffuse first reflection mid/high frequencies at the sweet spot.
The cost of the project is minimal compared to the time involved. I used 1/8" hardboard for the well dividers, 1/4" hardboard for the backs, 3/4" 2nd or better pine(any size is good just so there is enough) for the wells and unit frame. An ounce of carpenter's glue was used for each unit. No mechanical fasteners were used. Jigs were made out of scrap wood around the shop. A note on material selection is, if you prove yourself to the local supplier that a mess will not wait them after you browse thru their stock, they will be happy to open a new bundle at your request when display stock is low. I often found clear boards in the bundles. I also waited for sales and picked boards over several weeks. A list of materials and costs(tax not included) follows for 40 unit build.
(22) 1"x8"x6' $109.78
(8) 1"x6"x6' $31.92
(4) 1/8"x4'x8' hardboard $35.92 (try to find stock without machine marks an the back side. Lowes, in my case, had a smooth finish on both sides)
(2) 1/4"x4'x8' hardboard $17.96(only 8 square foot is needed from the second, cut pieces are usually available at higher cost per square foot)
(1) gallon of glue $15.98(used about one third of it)
View of the cut parts waiting for assembly.
Detail of one side of the unit frame. I used biscuits for the end joints. Note the small cut at the bottom of the biscuit slots to facilitate needed stock removal for the 1/4" hardboard back installation.
Assembly of the wells is a three step process. Speed is essential at this step to get all the parts glued and placed before clamping. Biscuit joints, back, well blocks, and dividers, as shown, are assembled and clamped this step. Note the wood parts flanking the unit. These are used to apply pressure to the wells when clamped. The two pieces of hardware at the top laying on the bench are used to put side pressure on the dividers and well blocks.
Clamps in place for a 30 minute press. This gives time to set up for the next unit and the second step assembly.
Second step gluing the two center wells.
Third step inserting the well assembly from step two.
(40) P1312's!
John