Crossover Board Mounting Detail:
Chris is building the pair of Original Large Advent EconoWaves seen in the background of the WIRED video. After removal of the stock crossovers, the opening in the rear panel for recessed input terminals and L-pad high-frequency attenuation (originally a three-position toggle switch) is 3" square. We cut a pair of 4" square pieces of 1/2" scrap plywood (3/8" would work fine, too,) and thru-mounted Dayton (Parts Express) input terminals and a 50-Watt L-pad in a cluster on center, leaving extra room below the binding posts for finger clearance when installing speaker leads. The spacing for the terminals is 3/4" center to center:
The 1" shaft L-pad stands off the board using the second nut and washer supplied with it such that its bezel and knob are flush with the rear surface. The binding posts are secured with one of the hex nuts provided, using the terminal lug as a washer. I prefer to save those, and typically use regular flat washers instead. At this point, the input terminal board would get foam tape to make a seal, and be screwed to the inside of the rear panel of the Advent cabinet, centering the control and input terminals in the opening:
Next, a toothed lockwasher (also provided, shown installed above,) goes on to insure good contact with the PC board input traces, the board itself, a second lockwasher, and the second hex nut. A 10mm socket tightens them securely:
The PC board then stands ~3/16" separate from the input terminal board providing clearance for the soldered connections and mounting hardware. 3/4" spacers at each corner (nylon shown, but metal is fine, too,) complete the crossover mounting in the cabinet:
The same approach is suitably used for direct mounting integral input Indignia crossovers, or on any solid panels up to 1" thick, without a recess.... :thmbsp: