Damn physics project...

falias

Golden Member
May 13, 2001
1,262
0
0
I need to make an instrument to play a easy 5 note melody and I want to make an instrument that I can tune using given measurements. I wanted to make chimes but I can't find the lenghts to produce each note... Anyone have any suggestions of what I can make easily? And any easy melodies to recommend? Thanks for the help.
 

LordMorpheus

Diamond Member
Aug 14, 2002
6,871
1
0
You CAN figure out how long the tube needs to be to produce a certain frequency, right, given the speed of sound through air?

Then you just need to figure out what frequency makes a specific note and then make the correct length tubing.

Also, make sure you get a clean cut on whatever you are using or it will sound like crap.
 

DanFungus

Diamond Member
Jul 27, 2001
5,857
0
0
Originally posted by: LordMorpheus
You CAN figure out how long the tube needs to be to produce a certain frequency, right, given the speed of sound through air?

Then you just need to figure out what frequency makes a specific note and then make the correct length tubing.

Also, make sure you get a clean cut on whatever you are using or it will sound like crap.

yeah, there's some equation for length = something involving wavelength and something over 'n' - n being whatever harmonic you wanted of the wavelength, and it depended on whether it was a closed tube or open tube. Then you'd just find whatever wavelength you needed, and you could get the length. I forget what the equation was, try looking at an AP physics equation sheet, I think that'd have it on there.

Unit 11 - that's what I was thinking of. Not sure how well it'd work for you in what you're trying to do since it'd be solid metal..
 

Hayabusa Rider

Admin Emeritus & Elite Member
Jan 26, 2000
50,879
4,265
126
Depends on the metal too. Aluminum is an awful. Steel is much better at resonating.
 

DrPizza

Administrator Elite Member Goat Whisperer
Mar 5, 2001
49,606
166
111
www.slatebrookfarm.com
Go for cheap: use PVC piping, 1 inch tubing.
Easy to do, there are several sites on the net for projects doing exactly what is described.
btw, to calculate the length of the pipe needed (roughly),
speed of sound = frequency * wavelength. Just find the frequency for the notes you wish to make (example: middle C = 256 hz) and calculate the wavelength.
For an open tube, 1/2 wavelength. For a closed tube: 1/4 or 3/4 wavelength. (Go for the closed tube and play the instrument by slapping your hand over the opening)
There's a small correction for the diameter of the pipe... I think it's add .6 * diameter to the length, but it's been a while, so I'm not positive.
 

Garion

Platinum Member
Apr 23, 2001
2,327
4
81
You need to build one of those cool PVC insturments like the Blue Man Group uses - Very cool show when we saw them about 10 years ago in Boston. They had one that was something like a PVC pipe organ that they played by pounding on the openings with something - Hands, ping-pong paddles, something. I also believe they had something that looked like a PVC trombone that they rapped on with drum sticks of some kind. Amazingly-cool stuff.

Physics project, possibly. Large, definitely. Fun? Absolutely.

- G