Ortho Acoustic WAW Part 4.

Waiting a week to remove the form was really boring. The outer shell came of pretty easy but I was quite surprised by how hard they stuck to the surface. The inner boards was more of a problem. I should have made the inner box out of polystyrene instead. The ides ans especially the bottom was totally stuck.

I had already kind of given up on concrete based entirely of weight but the rough surface (plasticize or not still needs a lot of vibration apparently) and this failed attempt didn't help either. I got a bit restless and applied some pressure to get one of the boards loose from the inside and it did not end well. Just look at the crack below (I used quite a lot of force but still).

The plug for the Neutrik NL4MP is still stuck in the concrete so I will never know how good or bad it would actually turn out. But I was not ready to give up on the basic concept of these speakers so I will finish them in MDF instead of concrete.

My first problem shifting from concrete to MDF was how to countersink the Neutrik NL4MP? I have newer thought of 3D-printing router templates before but printing the concrete plugs made me come up with the following concept. Two templates, the top edge got a bevel that lines up with the bottom of the speaker box. The left and right side is used to line it up with either side of the box. The left template is used to countersink the flange some 5mm. The right template is then inserted into the recess to line up the template in order to route the hole.

This is what the second template looks like inserted into the newly routed recess. It is a snug fit. The templates is also held in place with a piece of double sided tape.

And this is the final result after using both templates. This concept actually worked out much better than I thought.

And the Neutrik NL4MP chassis connector fits right in :)