String and Tin cans???

Question

I wish to try this with my brother across the house. But do the cans have to be tin, and is it ok if the string turns the corners of the house?(does the string have to be straight)

Answer 1

The 'cans' can be anything rigid enough to withstand some tension in the string, so even a plastic milk bottle or carton would be OK. But you do need to cut off the top of a bottle or carton, so you are 'facing' the large surface area on the bottom. The vibrations of the string turn the bottom into a sort of loud-speaker cone, by sending the vibrations into contact with a lot of air, via the large surface of the 'bottom'.

While a full answer would be more complicated, in practical terms, you do want the string to be straight. The sound vibrations that are trqansmitted along a tight string would be damped out if the string were in anything but the lightest contact with anything. It is, in a way, like a guitar string. Sound will vibrate in the string, and be audible, but only for the sections that can vibrate 'together'. As soon as you force the string onto a fret, a part of the string stops vibrating. And in your case, that means the sound does not travel from one can to another.