Here's how to make audio-cans from soup-cans, and some other things.
Step 1: Parts & Tools
Two large soup cans (Lidl chicken, vegetable & pasta - it's OK)
One Scotch Broth can (Lidl, better than OK)
Two small speakers (4 Ohm)
A wire coat-hanger
Electrical insulating tape
Various bits of wire
Expanded polystyrene foam
Most of the electrical content came out of an old phone I bought a while ago.
A knife blade
A soldering iron
Step 2: Mounting the speakers
Wash and dry the soup cans thoroughly.
Press the cans onto the foam to give you a rough size to cut.
Cut circles of foam, but trim ~ half an inch off two sides, you'll need this to get the foam into the cans (see later).
Press the speakers onto the foam to give you a rough size to cut.
Cut enclosures for the speakers, in this case the rectangular holes grip the magnet assemblies.
Taper a round edge to accommodate the speaker-cone, and ensure there's room for wire to pass through the foam block.
Step 3: Connecting the cans
Untwist the coathanger and straighten it out as best you can.
Bend 2 x 90o in the middle to give a square turn through 180o.
At the ends of the wire, bend each around 90o and trim (I had to use fencing pliers on this - it was tough stuff)
Form 90o bends at each end, and curve the centre section to fit your head.
Run (electrical) wires across the the coathanger, securing with tape, these will connect one speaker to the audio input from the other can.
Whilst I was at it I incorporated two sweet-wrappers for reasons which should be obvious now if not later...
I've then secured the end pieces to the main cans with small sections of steel cut from another can.
Holes were drilled through both and the two pieces of metal connected with a pair of nuts & bolts.