CEB Posted December 15, 2020 Share Posted December 15, 2020 I wonder how much experimentation it took to cut the PVC to get it in tune. I wonder if there are formulas to calculate the required footages for pitch? PVC Marimba thingy. Moe may know he is a classical organist and engineer. [video:youtube] Quote "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
Moonglow Posted December 15, 2020 Share Posted December 15, 2020 [video:youtube] Quote "We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw Link to comment Share on other sites More sharing options...
mate stubb Posted December 15, 2020 Share Posted December 15, 2020 Can't see the vids. Quote Moe --- Link to comment Share on other sites More sharing options...
mate stubb Posted December 15, 2020 Share Posted December 15, 2020 http://www.rwgiangiulio.com/math/pipelength.htm Quote Moe --- Link to comment Share on other sites More sharing options...
CEB Posted December 15, 2020 Author Share Posted December 15, 2020 http://www.rwgiangiulio.com/math/pipelength.htm Cool! Thanks a lot sir! Our Ancestors were amazing, considering the architecture, devices, and ideas they crafted without computers, without electricity and power tools. Eratosthenes In 240BC measured the length of shadows from two sticks and calculated the circumference of the Earth. Quote "It doesn't have to be difficult to be cool" - Mitch Towne "A great musician can bring tears to your eyes!!! So can a auto Mechanic." - Stokes Hunt Link to comment Share on other sites More sharing options...
232006 Posted December 15, 2020 Share Posted December 15, 2020 "I wonder how much experimentation it took to cut the PVC to get it in tune.." What you can have is a joining piece (unglued) on the bottom end, (will slightly change the length) which can be slid up or down slightly to fine tune - rather like some pipe organ pipes. Edit - after you have calculated the basic length for pitch and knocked off an amount to allow for the joiner of course... Quote Link to comment Share on other sites More sharing options...
Stokely Posted December 16, 2020 Share Posted December 16, 2020 I *almost* bought a giant pipe instrument (might have been made from PVC) for Kontakt during the Black Friday sales. I got the impression these was a huge pipe (or pipes) a couple feet across and many feet long though Kontakt is a dangerous thing... Quote Link to comment Share on other sites More sharing options...
KuruPrionz Posted December 16, 2020 Share Posted December 16, 2020 The calculations have been known for centuries. Pipe organs, flutes, fretted string instruments all use a consistent ratio for tempered scale but all have different methods of compensation for accuracy since the physics of the source of the sound are different (vibrating air or vibrating strings). There are variables in flutes (hole size, the air column is not perfectly adjusted for length, and strings - see below). Straight pipes like an organ or a PVC instrument in the OP are closer to the math. PVC pipe is not particularly resonant or musical but it doesn't have to be since you are exciting air inside the pipe for the note. I used that ratio long ago to cut fret slots for guitars, strings stretch when fretted so I compensated at the bridge with minor adjustments to the overall length, varying on the string diameter, construction (wound or unwound) and tension. It is not a perfect system but close enough for millions of guitarists. As someone pointed out above, you could thread one end and add a small extension. Cut the pipe just a bit short and fine tune it with the threaded end, then dribble some Loctite down into the threads when you have the note perfect to keep it from moving. Quote It took a chunk of my life to get here and I am still not sure where "here" is. Link to comment Share on other sites More sharing options...
Threadslayer Posted December 16, 2020 Share Posted December 16, 2020 I remember seeing a very effective visual demonstration of a standing wave in a pipe in Physics class many eons ago where they set up a clear acrylic tube with styrofoam pellets in it that had a 10 inch woofer mounted at each end. They attached the speakers out of phase to a sine wave generator and amplifier. When you hit the natural fundamental frequency of the pipe - or a harmonic of it - the styrofoam bits would pop up into a 3D representation of the natural resonant frequency. I found a few videos on Svengle just now, but none of them look as clean as the one I remember, where the fundamental popped up into a symmetrical hourglass shape, clearly showing the nodes with very little distortion. Here's one that's a little messy but gives the idea: [video:google] Quote Whenever you find yourself on the side of the majority, it is time to pause and reflect. -Mark Twain Link to comment Share on other sites More sharing options...
Delaware Dave Posted December 16, 2020 Share Posted December 16, 2020 [video:youtube] Quote 57 Hammond B3; 69 Hammond L100P; 68 Leslie 122; Kurzweil Forte7 & PC3; M-Audio Code 61; Voce V5+; Neo Vent; EV ELX112P; GSI Gemini & Burn Delaware Dave Exit93band Link to comment Share on other sites More sharing options...
KuruPrionz Posted December 16, 2020 Share Posted December 16, 2020 ^^^ The gentleman playing the crystal glasses winz the interwebz!!!! Beautiful! Quote It took a chunk of my life to get here and I am still not sure where "here" is. Link to comment Share on other sites More sharing options...
elif Posted December 17, 2020 Share Posted December 17, 2020 Oh well... [video:youtube] Quote Link to comment Share on other sites More sharing options...
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