This is a design I started myself after seeing something similar in China. I am not sure how well theirs work or how they are made. So, I decided to experiment with my design of a graphophone modeled in Fusion 360. This is still an experiment but I wanted to share in case others have ideas they can offer to make this better. Right now it does amplify the sound but it is directional and a tad high on the treble side. The tone may be fixed with a thicker-walled horn or maybe even a different filament type. Also, this design was customizable to the speaker location on an Android phone.

I printed the base with a 20% infill. The horn was printed solid. I did cut out the bottom of the box so it would use less filament. However, you do have to support these areas. The horn I stood on the small end so the horn is standing. I used tree supports and they did very good.

Please share with me any ideas you may have to make this better or remake to suit your needs.