Yes, but you only used two layers of 3/4" mdf, so that makes sense. I will be using a 42lb driver with 28" diameter sonotube, so I will use 3 layers of 3/4" mdf plus an additional layer of 1/2" plywood. Even if I didn't use the plywood, that's 2.25" of mdf. The longest binding posts I can find are 1.5", so I would have to cut large holes through layers 1 and 3 to act as countersinks for the narrow holes in layer 2. I'd then have to fit my fingers in these countersink holes to run wire through the binding posts and to make the sodder. Too much hassle. I truly do appreciate the suggestion, but I think I'll stick with the binding posts being positioned low on the back of the tube.