There are two designs of base for this model. The base you choose depends on the type of phone you use. If your phone has a loudspeaker along its bottom edge use the iPhone base. If the loudspeaker is anywhere on the back of the phone use the Galaxy base.
Print out the parts of the base that you are using onto thin coloured card. Any coloured photocopier card should be ideal. Choose two complementary colours of card.
This project is the Mk II new and improved version of the Phono-Horn project also available on Instructables here.
It was originally published on www.robives.com
Step 1: Making The Horn
Fold over the end tabs to make a triangular section tube on each of the eight horn pieces. This gives strength and rigidity to the open end of the horn.