I've got several of these "sirens"/noise makers:
I want to modify (or replace) the top plate for cosmetic (and mechanical) reasons.
E.g., in a couple of cases, I want the cover to appear as a 5" diameter, FLAT circular plate with the "port" located in the center. In every case, these will be subject to reasonably close (though casual) inspection so I really don't want them to look amateurish.
Note that the current "top" is rectangular (instead of square or circular). And, that it has a bowed shape along the long axis, instead of being flat.
First thought was to 3D print a replacement. And, hope I could solvent wash it to get a reasonably smooth finish.
The problem is the center portion of the port. It's a horn loaded driver for extra efficiency. So, what you don't see in the photo is the shape of the interior surfaces! If you were to slice the cover in half directly through the center, along the long axis, you'd get a cross section similar to pictured below.
The pressure wave begins at the bottom of the arrow and winds its way around the folds in the "horn" until exiting through the visible port. Getting the shape of this curve correct in CAD would be a PITA (I know the principles but not the details!).
So, I'd like to cut out the center portion of the cover and mount it to -- or build around it -- something more easily fashioned. E.g., cut a hole as large as the exit opening in the port in a sheet of plastic and "glue" the port assembly to that.
But, I assume this will be a noticeable kludge. Any pointers as to how I might make it "more presentable"? I'm tempted to try a solvent wash (and paint, thereafter) but don't have any "spares" of these to experiment on so want to be reasonably confident of any approach before starting.
Another approach would be to perforate a plain cover plate (instead of cutting a big hole in it) and mount this to the rear. I'm not sure how that would affect the SPL. And, the "exposed port" looks cooler! :<
I want to modify (or replace) the top plate for cosmetic (and mechanical) reasons.
E.g., in a couple of cases, I want the cover to appear as a 5" diameter, FLAT circular plate with the "port" located in the center. In every case, these will be subject to reasonably close (though casual) inspection so I really don't want them to look amateurish.
Note that the current "top" is rectangular (instead of square or circular). And, that it has a bowed shape along the long axis, instead of being flat.
First thought was to 3D print a replacement. And, hope I could solvent wash it to get a reasonably smooth finish.
The problem is the center portion of the port. It's a horn loaded driver for extra efficiency. So, what you don't see in the photo is the shape of the interior surfaces! If you were to slice the cover in half directly through the center, along the long axis, you'd get a cross section similar to pictured below.
The pressure wave begins at the bottom of the arrow and winds its way around the folds in the "horn" until exiting through the visible port. Getting the shape of this curve correct in CAD would be a PITA (I know the principles but not the details!).
So, I'd like to cut out the center portion of the cover and mount it to -- or build around it -- something more easily fashioned. E.g., cut a hole as large as the exit opening in the port in a sheet of plastic and "glue" the port assembly to that.
But, I assume this will be a noticeable kludge. Any pointers as to how I might make it "more presentable"? I'm tempted to try a solvent wash (and paint, thereafter) but don't have any "spares" of these to experiment on so want to be reasonably confident of any approach before starting.
Another approach would be to perforate a plain cover plate (instead of cutting a big hole in it) and mount this to the rear. I'm not sure how that would affect the SPL. And, the "exposed port" looks cooler! :<
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