Ortho Acoustic WAW Part 7.

Boxes built but I was still missing a grill, top or hood a la OA-50. The original one was made out of wire mesh which looks really good. But I was a bit worried that the bamboo fiber paper cone of the W5-2143 would shine through as it is not black. I therefor went for something covered with fabric like on the OA-50.2. I could not find any pictures of how the frame was constructed. I considered using aluminum profiles but it would be quite expensive given that I would need close to 3 meters for two speakers.

I had a piece of 8 mm planed pine laying around so I ended up ripping it into 8x8 mm strips. I then used the 3D printer to make a set of brackets. The ones on the bottom got a 1 cm extension that serves as "feet" and also keeps it in place on the baffle. Below is a picture of all pieces needed for one speaker.

I glued the strips to the brackets using CA glue. Here is one of the bottom brackets.

I then painted the frames black (I actually used a water based lacquer stain applied with a sponge).

The next step was a bit of chance. I had some speaker cloth laying around but it was too dense (effected the upper frequency band) so I started to look for something better. I ended up using a really nice speaker cloth but it was quite see through. The recommendation was to use it in double layers but I wanted to keep it as audio transparent as possible so I went with a single layer.

The fabric was quite sheer so I was struggling a bit to come up with a way to create a nice seam that would also hold around the standing edges and around the sharp corners. Hemming tape would probably be the way to go but I found this product Wonder Tape by Prym and I just had to try it out. It made the job really easy but it is not as transparent as hemming tape and it is also white so you have to be quite meticulous with your sewing to prevent it from showing through the seam. If it does, just use a black marker to stain it black. :)

I calculated the stretch of the fabric to be 12% and made a template 10% smaller than the wooden frame (on all dimensions but the height). This is a bit of waste of fabric and wonder tape but it made fabrication really easy. I put the template on the fabric and applied strips of wonder tape around the outer edges.

Remove the template and the tape is left on the fabric. Cut the fabric outside of the tape (I left around one cm, it will eventually be trimmed).

Remove the protective layer for the other side of the tape and piece each side of the seam to the other side of the fabric.

Finish it up with a tight seam just shy of the inside of the tape (I used zigzag with 50% on the tape and 50% on the fabric). Trim the excessive fabric to finish it off like in the picture below.

This is what the frame looks like sitting on top of the box...

And this is what it looks like covered with fabric. I think it mimics the original OA-50.2 quite well. There is a slight see through of the W5-2143 and the baffle but I actually kind of like it. I am happy with the overall look and so is my wife. ;)

Speakers ready but I still need to measure it and start working on an active filter for it. I am planning to replace the plate amps with something else and that might end up with something else for the W5-2143 too. I would like to build something around Rod Elliott's P48a but I am in no hurry since these speakers works amazingly well in its current setup.