Create a brand new diaphragm for your soundbox with a 3D printed die and some thin aluminium sheet.

Place your die onto the aluminium piece then mark around it and cut it out, what I like to do is to score around the die with a sharp hobby knife and then by bending the aluminium slightly back and forth your shape should break free.

Now place the cut piece of aluminium onto the die and rub over it with your finger, this will create slight indentations that can be used as a reference on where to start.

Using a embossing tool (I use a 3mm and 1.5mm brass rod that i rounded the points) start in the centre and gently start "rolling" the aluminium into the die, go slow too much pressure at once will cause a tear. We want to slowly stretch the aluminium into the die.

TIP: If you are having trouble with your embossing tool "grabbing" onto the aluminium you can add some oil to lubricate it.

Now we are going to take the metal rod and roll/scrape it over the die a few times in different directions.

Doing this will flatten out the diaphragm getting rig of any wrinkles and it will also work harden the aluminium giving you a much stiffer end result.