Оригинал на русском: http://shura.luberetsky.ru/2008/12/11/antikrizisnyjj-dinamik/
Today, when all the world is struck by an economical crisis, a well-known Russian rock musician Pauk (Spider) advises to do some downshifting — for example, to go to the village and to grow pigs. Well, in the village you will need to listen to «Corrosion of metal» — the band of Pauk, so you need a powerful audiosystem to produce real hell madness. Today I will tell how to make cool loudspeakers out of trash. The original designer is Jose Pino of Mexico.
All you need is some magnets, paper, piece of cardboard, thin enameled wire (I will tell where to get it from) and a styrofoam plate from the nearest supermarket.
Also you will need some glue. I used «Moment» for paper and UHUpor for foam.
You can get the magnets in the shop or just steal them from the office.
So, let’s start. You should turn some layers of a paper band on a magnet (I used three rather weak magnets put together) and glue it to get a paper cylinder.
Then make a second layer, but not glue it to the first. You should get two paper cylinders — a smaller and a larger one.
Now throw away the smaller one, and the bigger will become a base for the coil of enameled wire. You will have to use the thinnest wire available, something like 0.1 or 0.2 mm — or AWG 32-38.
If you try to buy enameled wire, it will either be very expensive, or you will buy a several kilometres hank of cable. Nobody buys it, and if you need enameled wire, you could search it in old transformers, electric motors, CRT TVs and monitors and other similar things. In my box full of trash I found an output transformer of an old radio receiver «Mayak-202», which had the wire I needed.
Glue the paper cylinder to the centre of styrofoam plate and begin to wind the coil, leaving a free piece of wire of 5-7 inches. You could put the magnet inside not to crush the cylinder.
The resistance of a coil should be from 8 to 32 Ohms. I made 100 wounds and then protected it from loosing with a piece of Post-it paper.
After that I covered the ends of the wire with solder (you need not to crimp the insulating enamel — it will burn itself from the soldering iron heat) and measured the resistance, getting some 13 Ohms.
Now we only need to hang the loudspeaker on some base. I used a big piece of cardboard, which can hold two loudspeakers and a simple amplifier. Take two business card-sized pieces of paper, fold them and glue to the speaker:
Now we make two holes for the wire in the cardboard and glue the suspension and the magnet to the speaker base. Be careful not to glue the magnet to the coil or the plate — the speaker will not work then!
The loudspeaker is ready! To check it, you only have to take a battery and touch its terminals with the ends of the speaker wires. You should hear «clicks» when touching.
The sensitivity of the speaker is quite poor, so you will need an amplifier to build a really powerful anticrisis stereosystem.