Hi Marty,

I measured them on the outside but with the unevenness of the aquaplas coating, it was difficult to interpolate what the ID was. I mentioned the points, when plotted, would need smoothing. I'm glad to see Alan's curve is actually not that bad. There would be no way to use calipers like I did on the waveguide. Very interesting to see the slight compression on the side angle view of the waveguide up to the 2" point. I guess I have to post that here. I did a scan as Audiomind found my measurements difficult to read.