FFT and a signal generator are scientific equipment, it just happens that phones have advanced far enough to accommodate it. 20 years ago a fast rate response FFT that fits in a pocket would have been worth considerable money. Affordability does not necessarily make things less scientific, as seen in this neat demonstration
Except that the spectrum analyzer and signal gen from a tablet are pretty much garbage as scientific pieces of equipment, so none in their right mind would consider them so.
Its easier to identify resonances and their associated harmonics if you view it in Spectrograph or a waterfall graph or even an FFT with averaging on. This allows you to better see the rate at which each frequency decays. You could also attach a piezo (very cheap) pickup to the surface to eliminate the losses due to the air gap between your tablet microphone and the plate. If you were to excite the plate by multiple resonances at the same time the destructive interference patterns created are amazing.
Matthias, I gotta say I love the variety of subjects you cover in your videos. It's so awesome to learn about useful woodworking knowledge as well as random bits of applied science like this! Seeing stuff like this helps to re-spark the same sort of tinkering I used to do before life got so busy; if you have time to do it with household responsibilities AND kids, I surely can too. Keep doing what you do!
I'm an amateur luthier, what you are doing is called "tap tuning" I use the same setup as you but with tea, not sand or sugar. When I got fascinated by this, I researched it and found an example of "tap tuning" using the violin bow to excite the particles, so this practice goes back hundreds of years. There is an old video on youtube ( black and white and silent) showing a bow being used to "tap tuning" a violin plate look up "American violin maker - James Reynold Carlisle" 2.40 minutes in it shows the "tap tuning." OK here is the challenge. Carve all the parts of a violin tune them and make one that like a stradstradivarius. I've been trying for years!
A profound scientific approach. Physics teachers usually do this experiment with plates that are supported in the middle and get highly symmetrical patterns. It was interesting to see that the slightly assymmetrical tension in a plate with these bend edges results in assymmetrical patterns.
A very long time ago, I saw a science program on TV where they took a steel plate, sprinkled it with fine sand, then used a violin bow to stroke the edge of the plate. Stroking the edge in different places produced different patterns.
Your mind works in mysterious ways! If only there were a productive way to use this info. Experiments like this is how breakthroughs in technologies are born! Leave it to you to come up with different ways to use wood strips! Ha Ha! I learn a great deal from you. Using salt was brilliant to show wave patterns. Another cool experiment would be to do the same method on ply or solid wood the determine the resonance of a given piece of wood for speaker design. Thank you for doing projects you don't normally see on UA-cam. Thankz and Happy New Year!
I think a better solution would be to reduce the rate at which plate loses energy. Namely if it does not lose energy very fast, then just running the sound source for longer should also result into the plate accumulating more vibrational energy. I think this can be reduced by supporting the plates along one of its nodes of that mode. However changing the way the plate is supported might also change the mode your are trying to excite slightly. Another to reduce this should be choosing a plate which is made of a stiffer material.
they make special devices to attach the plates to and also because of the side walls the patterns wil be verry different to normal. you can also think to use glass plates
So cool, thanks for taking the time to share this! You might get even better performance if you measure the frequency with the same boundary conditions to which you're applying the forcing function (don't hold and tap, set it on the boards and tap)... aaaand then I watched the rest of the video, and that's exactly what you did after the first one.
I was just waiting for the pattern to make a picture or words. Lol kinda thought he might end it that way for a laugh. Very glad to have been watching his channel for almost two years. He has has interesting videos.
I would love to be there for Mr. Wizards science hour. So many variables to play with. Can’t wait to see your kids in these types of videos. Thanks for posting!
To solve your power problem you could improve the coupling (air dissipates a lot of energy). You could try and make a diy version of those "seat transducer" they use in facy cinemas. Just take an old speaker, cut most of the diaphragm and glue something like a straw or a dowel to the center. That way you basically make something that pokes things at precise frequencies without wasting energy moving air
Robert Hooke performed this experiment during the late 1600's using flour, a glass plate and a bow from a violin, if my memory serves me right. It's still cool to see.
I use that same spectrum analyzer app to time my drums! The device it is run on makes a big difference add far as frequency response is concerned. Different microphones I'm guessing.
The momentum of your exciter (drum stick) can excite different modes. Your finger has little momentum so it excites higher modes. Use a heavier drum stick to excite lower modes. That's why a bass drum stick is much bigger than those for a snare. I use the soft part of my fist to ring the bollards while pumping gas.
Instead of a speaker have you considered connecting a DC motor with a short arm off the shaft to the back of the pan to make the entire pan a speaker? I got the idea from Bruce Yeany who did it with paper plates and I thought it would be cool to try for standing waves.
"without any special scientific equipment" he said while using speakers the pioneers of acoustic science could only dream of and a computer more powerful than what took mankind to the Moon. But cool experiment and even cooler that consumer products have become so advanced that everyone can do their own science or whatever they want to do.
I wonder how much the speaker's magnetics influenced the vibrations on the panel, and perhaps interfered with the air coupling between the speaker cone and the pan.
What would happen if you supported the plate from the corners instead of the middle of each side? Would the pattern change? What if you suspended it from some strings so it was floating in air? Just curious what would happen. Would make a good kids science project. Thanks for sharing this Matthias.
What is the advantage of knowing where the nodes of vibration are for certain frequencies? What I mean is, how does it help you? The patterns are very interesting!
InTnMnNmAz he's been toying with sound characterization for awhile, ever since he accidentally discovered air raid siren when building a blower for his dust collector. He then made a real air raid siren, then he used resonance testing to try and sound dampen one of his blowers. He then did the wave art contraption recently to explain why bells make the noises they make and ring at different notes, which led to this video, where a plate sounds at many different notes.
Put a long handle on that speaker and use it as a magnetic pick up tool. Can you do that to the sheet... Take a pic. Use a different freq. Take another pic. Etc... Then lay the pics on top of each other, and decide how, if you partially cut out the open spaces... One for each frequency. You can get several 'tongues' on the sheet. And would that work for a tongue drum?
"I would like to take a moment to thank our sponsor for this video, Windsor Table Salt. Windsor Table Salt has been serving me and my family for generations...."
Would you get better results if you hung the panel from the ceiling with fishing line, somewhat like using a bell it sounds different whenever you hold it instead of hanging it. If that makes sense
It is important to identify the natural frequencies with the same boundary conditions as when you excite it... in other words you should give it a bang when it's in the same position as when you excite it with the speaker. otherwise the natural frequencies will not match and just maybe clamping it down on both sides would even give cleaner patterns. still that was great!
cool, can you try playing multiple frequencies simultaneously? either playing back the original or even playing two frequencies with two different speakers..
Maybe try switching abruptly between two or more of those frequencies to animate the patterns? The second frequency that you showed 'ringing out' had a strong harmonic so you might be able to flip between those without needing to move the speakers.
Next time, lay the sheet (cookie sheet, dryer panel, etc.) so that it's in contact with the speaker enclosure...with the corners supported just enough to keep the sheet level. The fact that the speaker is in an enclosure will prevent the sheet from impeding speaker voice coil travel, but putting it in contact with the sheet will allow you to get nice effects at much lower dB SPL. Typically, experiments like these are done using a contact transducer (an example of which might be one of those home theater subwoofers that get bolted directly to the floor joists under the room that the system is in....or an old B.E.S.T. planar transducer, that gets plastered right into a wall and turns the sheetrock in that wall into the sound radiating element) which most people don't have just laying around! An alternative might be getting a much larger speaker (12" - 15") with a much larger voice coil, then gluing a sturdy cardboard tube (toilet paper or paper towel tubes will NOT be strong enough) centered on the speaker's paper cone AND glued to the center of the sheet. You'd have to support the sheet corners and fix the speaker in place...since vibration will make it want to 'walk' across the table. It's also better to use an AF signal generator that allows some fine adjustment 'on the fly'....like with a control knob. You'd be surprised at the difference just a tiny frequency adjustment (even just 1 or 2 Hz) can make. ....and yes, there are pieces of art out there that use the results (permanently fixed in place) as a background....or even the subject!!
What do you suppose would happen if you cut the edges off of your sheet so that it was flat, and then suspended it at nodes? My guess is that you'd get a different but similar pattern, and that it would ring longer, but also make a bigger mess. Kind of a large 2-D wind chime!
This would be interesting to try with a stick on exciter like the Dayton Audio DAEX25. I'v experimented with sticking those to guitars and its a bunch of fun.
I think I've only ever seen this demonstration in two modes: a linear oscillator is placed upward and the plate bolted to it in the center, and a static bar pointing upward bolted to the plate in a similar manner and bowed with a bowstring. It makes sense that your method also works, and for everyday metal plates in product design. However, sound is very inefficient at delivering power. Added, with the demonstration that location of the sound source not changing the shape of the pattern, only it's intensity to reveal itself, I'd like to suggest two changes: A. Attach an arm or larger foam dome to a speaker and apply physical contact to the object being observed. Apply the device at different locations and different directions. Does the pattern remain the same or merely affect the intensity? B. Remove the body of the speaker and reduce it to the coil, or simply drive a coil of wire with your amp and frequency generator. Hold the coil with the signal running near the plate. This might be more effective than the speaker housed in it's magnetic shielding and air gaps.
Also, using a frequency generator that you can adjust continuously, or at least smooth-ish would be nice to discover frequency modes or superpositions of two.
It's amazing how sound can move physical objects. This helps me believe the story of how the ancient walls around Jericho fell down.... Joshua 6 : 20 (KJV) So the people shouted when the priests blew with the trumpets: and it came to pass, when the people heard the sound of the trumpet, and the people shouted with a great shout, that the wall fell down flat, so that the people went up into the city, every man straight before him, and they took the city.
do the frequencies have a common denominator and are therefore setting up the standing wave in the same orientation, or are they all over the place meaning the standing waves are all separate?
I've been watching your videos a while ago, and I'm just a little surprised that you have so many new ideas about where to experiment. Now do you work with the sounds and waves? Congratulations to! Did not Nigel John Stanford's video give you the idea? If so, what's next? After many carpentry machines, you just do not do a jukebox like Wintergatan? I look forward to newer videos and wish you a great deal more work! Keep it up! :)
But, you could equally make those sounds with another piece of metal right? It doesn't need to be a speaker, it just need to produce the correct resonant frequency .... so you could make the sound mechanically right? With the right shaped piece of metal beneath the top one... maybe a metal guitar string? Can you direct the salt... say to the edge of the tray?
is there someway to measure material thickness and inconsistencies? The diagonal lines must mean some kind of difference, if the speaker would be placed in the center of the plate, shouldn't that give symmetrical lines transferring from the center then?
johan jönsson yes and now. Using this it would be fairly hard. The asymmetry we see on this experiment is most likely due to asymmetrical supports for the plate and therefore asymmetrical tension along the plate. While material thickness and consistency certainly affects the wave pattern, it would probably be hard to separate the effect from the effect the tension has.
i love your videos always very intresting mostly audio stuff and with your woodworking skills i'm sure that you can build better sounding and better looking speakers than what you use maybe for a next project : )
The problem i can see with those sheets is the raised edge, that edge will resonate at a different frequency, which may counteract the main sheet freq in the harmonics, best to use a flat sheet.. Most use a direct contact transducer, probably uses less power to resonate the sheet.
It would have been really fun to see a sine sweep. That is if you can come up with something to generate the signal. They are really cool to watch, as you can see the system as it passes through the fundamental frequencies.
It's interesting how chaotic the modes look. If the metal was perfectly manufactured, you would think the modes would look more consistent and predictable. But inconsistencies in the metal allow these weird modes to show up.
You could have seen the frequencies must better with an app which shows the harmonics not the spectre. I don't know if there's an app for phone or tablets but I used them all the time when I was studying electronic music as a musicology student.
Workshop physics. UA-cam’s best utility. More, please.
5:31 spray with varnish and sell to the Tate gallery for $ 6 million
a little spray would send all the sand away
Free Saxon that would probably sell
... boy you never really know what you're gonna get with this channel do you
keeps it fresh u know
FFT and a signal generator are scientific equipment, it just happens that phones have advanced far enough to accommodate it. 20 years ago a fast rate response FFT that fits in a pocket would have been worth considerable money. Affordability does not necessarily make things less scientific, as seen in this neat demonstration
Except that the spectrum analyzer and signal gen from a tablet are pretty much garbage as scientific pieces of equipment, so none in their right mind would consider them so.
Its easier to identify resonances and their associated harmonics if you view it in Spectrograph or a waterfall graph or even an FFT with averaging on. This allows you to better see the rate at which each frequency decays. You could also attach a piezo (very cheap) pickup to the surface to eliminate the losses due to the air gap between your tablet microphone and the plate. If you were to excite the plate by multiple resonances at the same time the destructive interference patterns created are amazing.
Matthias, I gotta say I love the variety of subjects you cover in your videos. It's so awesome to learn about useful woodworking knowledge as well as random bits of applied science like this! Seeing stuff like this helps to re-spark the same sort of tinkering I used to do before life got so busy; if you have time to do it with household responsibilities AND kids, I surely can too. Keep doing what you do!
Very nice. The asymetry you're witnessing is due to the different boundary conditions on your plate (longer fixed edge on the left than on the right).
I'm an amateur luthier, what you are doing is called "tap tuning" I use the same setup as you but with tea, not sand or sugar.
When I got fascinated by this, I researched it and found an example of "tap tuning" using the violin bow to excite the particles, so this practice goes back hundreds of years. There is an old video on youtube ( black and white and silent) showing a bow being used to "tap tuning" a violin plate look up "American violin maker - James Reynold Carlisle" 2.40 minutes in it shows the "tap tuning."
OK here is the challenge.
Carve all the parts of a violin tune them and make one that like a stradstradivarius.
I've been trying for years!
A profound scientific approach. Physics teachers usually do this experiment with plates that are supported in the middle and get highly symmetrical patterns. It was interesting to see that the slightly assymmetrical tension in a plate with these bend edges results in assymmetrical patterns.
A very long time ago, I saw a science program on TV where they took a steel plate, sprinkled it with fine sand, then used a violin bow to stroke the edge of the plate. Stroking the edge in different places produced different patterns.
That sounds really cool! I'm off to search UA-cam to see if anyone has a video where they did that..
thats the way Chladni the semi inventer of this effect tested this phenomenon
Suzanne P check out Steve Mould's UA-cam channel, he does this exact thing in one of his vids.
Yes I experienced that in ‘real’, it’s pretty cool. ;)
This is really cool! I could see someone taking photos of those patterns and selling them as art. Really interesting video.
What a great woodworking channel!
Your mind works in mysterious ways! If only there were a productive way to use this info. Experiments like this is how breakthroughs in technologies are born! Leave it to you to come up with different ways to use wood strips! Ha Ha! I learn a great deal from you. Using salt was brilliant to show wave patterns. Another cool experiment would be to do the same method on ply or solid wood the determine the resonance of a given piece of wood for speaker design. Thank you for doing projects you don't normally see on UA-cam. Thankz and Happy New Year!
And this is why you are the most interesting woodworker to watch on UA-cam
Could you get better performance by connecting the plate physically to the speaker coil rather than relying on air to transmit the energy?
yes, just didn't want to destroy (another) speaker
I think a better solution would be to reduce the rate at which plate loses energy. Namely if it does not lose energy very fast, then just running the sound source for longer should also result into the plate accumulating more vibrational energy.
I think this can be reduced by supporting the plates along one of its nodes of that mode. However changing the way the plate is supported might also change the mode your are trying to excite slightly. Another to reduce this should be choosing a plate which is made of a stiffer material.
they make special devices to attach the plates to and also because of the side walls the patterns wil be verry different to normal. you can also think to use glass plates
Resting the plate on two of the nodes would also allow it to resonate more freely. And resting it on foam would help too.
Yes, but Matthias' point was to do it without special equipment.
So cool, thanks for taking the time to share this! You might get even better performance if you measure the frequency with the same boundary conditions to which you're applying the forcing function (don't hold and tap, set it on the boards and tap)... aaaand then I watched the rest of the video, and that's exactly what you did after the first one.
I was just waiting for the pattern to make a picture or words. Lol kinda thought he might end it that way for a laugh. Very glad to have been watching his channel for almost two years. He has has interesting videos.
Very cool. We deal with this with structures all the time but this is a great visualization
This is actually far more interesting than the "perfect" patterns that we see in most videos.
Who knew that simple baking sheets sounded so lively!!!!!
Love how the nodes move depends on where you have the speaker.
I would love to be there for Mr. Wizards science hour. So many variables to play with. Can’t wait to see your kids in these types of videos. Thanks for posting!
Thanks. Very nice. I always enjoy your videos.
To solve your power problem you could improve the coupling (air dissipates a lot of energy). You could try and make a diy version of those "seat transducer" they use in facy cinemas. Just take an old speaker, cut most of the diaphragm and glue something like a straw or a dowel to the center. That way you basically make something that pokes things at precise frequencies without wasting energy moving air
Robert Hooke performed this experiment during the late 1600's using flour, a glass plate and a bow from a violin, if my memory serves me right. It's still cool to see.
I use that same spectrum analyzer app to time my drums! The device it is run on makes a big difference add far as frequency response is concerned. Different microphones I'm guessing.
try it with a round plate, you will find one mode of vibration much more intense.
The momentum of your exciter (drum stick) can excite different modes. Your finger has little momentum so it excites higher modes. Use a heavier drum stick to excite lower modes. That's why a bass drum stick is much bigger than those for a snare. I use the soft part of my fist to ring the bollards while pumping gas.
Instead of a speaker have you considered connecting a DC motor with a short arm off the shaft to the back of the pan to make the entire pan a speaker? I got the idea from Bruce Yeany who did it with paper plates and I thought it would be cool to try for standing waves.
I very much appreciate that kind of video. Thanks for spending your time doing it and sharing it! And happy new year !
thats really a nice experiment there
"without any special scientific equipment" he said while using speakers the pioneers of acoustic science could only dream of and a computer more powerful than what took mankind to the Moon. But cool experiment and even cooler that consumer products have become so advanced that everyone can do their own science or whatever they want to do.
A generic modern computer is not considered scientific equipment...
I wonder how much the speaker's magnetics influenced the vibrations on the panel, and perhaps interfered with the air coupling between the speaker cone and the pan.
What would happen if you supported the plate from the corners instead of the middle of each side? Would the pattern change? What if you suspended it from some strings so it was floating in air? Just curious what would happen. Would make a good kids science project. Thanks for sharing this Matthias.
I love your vids Matthias you have inspired me to do wood work keep up the good work and congrats on 1 mill subs👍👌
So can this be used to analyze the "accuracy" of a sheet of metal? I assume the imperfect resonations are because of imperfections in the metal.
Wow, i uses to like you with wood workin, now you just became super nerd on me... more building please
What is the advantage of knowing where the nodes of vibration are for certain frequencies? What I mean is, how does it help you? The patterns are very interesting!
Matthias, just starting to watch the video, u need log scale for that audio spectrum analyzer to make things easier ;-)
What was the impetus that drove this interesting investigation? Prepping for a future video on something? Your curiosity sparks my curiosity.
InTnMnNmAz he's been toying with sound characterization for awhile, ever since he accidentally discovered air raid siren when building a blower for his dust collector. He then made a real air raid siren, then he used resonance testing to try and sound dampen one of his blowers. He then did the wave art contraption recently to explain why bells make the noises they make and ring at different notes, which led to this video, where a plate sounds at many different notes.
Put a long handle on that speaker and use it as a magnetic pick up tool. Can you do that to the sheet... Take a pic. Use a different freq. Take another pic. Etc... Then lay the pics on top of each other, and decide how, if you partially cut out the open spaces... One for each frequency. You can get several 'tongues' on the sheet. And would that work for a tongue drum?
Alright, now write a series of tunes that draws the sand into a pictures while also sounding pleasant.
"I would like to take a moment to thank our sponsor for this video, Windsor Table Salt. Windsor Table Salt has been serving me and my family for generations...."
You made a Sonic Etch a Sketch, Doctor Who would be proud of you
Would you get better results if you hung the panel from the ceiling with fishing line, somewhat like using a bell it sounds different whenever you hold it instead of hanging it. If that makes sense
Very interesting Matthias. But where is this leading to?
It is important to identify the natural frequencies with the same boundary conditions as when
you excite it... in other words you should give it a bang when it's in the same position as when you excite it with the speaker. otherwise the natural frequencies will not match
and just maybe clamping it down on both sides would even give cleaner patterns. still that was great!
It is kind of hard to believe that the vast majority of people carry around several super-computers of 20 years ago in our pockets.
I wish you were my science/math teacher when I was in school.
Great video!!
cool, can you try playing multiple frequencies simultaneously? either playing back the original or even playing two frequencies with two different speakers..
Maybe try switching abruptly between two or more of those frequencies to animate the patterns? The second frequency that you showed 'ringing out' had a strong harmonic so you might be able to flip between those without needing to move the speakers.
Next time, lay the sheet (cookie sheet, dryer panel, etc.) so that it's in contact with the speaker enclosure...with the corners supported just enough to keep the sheet level. The fact that the speaker is in an enclosure will prevent the sheet from impeding speaker voice coil travel, but putting it in contact with the sheet will allow you to get nice effects at much lower dB SPL.
Typically, experiments like these are done using a contact transducer (an example of which might be one of those home theater subwoofers that get bolted directly to the floor joists under the room that the system is in....or an old B.E.S.T. planar transducer, that gets plastered right into a wall and turns the sheetrock in that wall into the sound radiating element) which most people don't have just laying around! An alternative might be getting a much larger speaker (12" - 15") with a much larger voice coil, then gluing a sturdy cardboard tube (toilet paper or paper towel tubes will NOT be strong enough) centered on the speaker's paper cone AND glued to the center of the sheet. You'd have to support the sheet corners and fix the speaker in place...since vibration will make it want to 'walk' across the table. It's also better to use an AF signal generator that allows some fine adjustment 'on the fly'....like with a control knob. You'd be surprised at the difference just a tiny frequency adjustment (even just 1 or 2 Hz) can make.
....and yes, there are pieces of art out there that use the results (permanently fixed in place) as a background....or even the subject!!
What do you suppose would happen if you cut the edges off of your sheet so that it was flat, and then suspended it at nodes? My guess is that you'd get a different but similar pattern, and that it would ring longer, but also make a bigger mess. Kind of a large 2-D wind chime!
Best announcement video I️ have seen, I️ think
Matthias, you present some great content. Would you revisit this experiment and keep the frequency at 432 Hz? Very interested.
This would be interesting to try with a stick on exciter like the Dayton Audio DAEX25. I'v experimented with sticking those to guitars and its a bunch of fun.
Is that a piece of same dryer from which you harvested a top for the big bandsaw table?
I think I've only ever seen this demonstration in two modes: a linear oscillator is placed upward and the plate bolted to it in the center, and a static bar pointing upward bolted to the plate in a similar manner and bowed with a bowstring.
It makes sense that your method also works, and for everyday metal plates in product design. However, sound is very inefficient at delivering power. Added, with the demonstration that location of the sound source not changing the shape of the pattern, only it's intensity to reveal itself, I'd like to suggest two changes:
A. Attach an arm or larger foam dome to a speaker and apply physical contact to the object being observed. Apply the device at different locations and different directions. Does the pattern remain the same or merely affect the intensity?
B. Remove the body of the speaker and reduce it to the coil, or simply drive a coil of wire with your amp and frequency generator. Hold the coil with the signal running near the plate. This might be more effective than the speaker housed in it's magnetic shielding and air gaps.
Also, using a frequency generator that you can adjust continuously, or at least smooth-ish would be nice to discover frequency modes or superpositions of two.
This is interesting and all, yet I would like to see you doing stuff in the wood fabrication area.
How good are your kid's science fair projects going to be, when the time comes.....10/10
It's amazing how sound can move physical objects. This helps me believe the story of how the ancient walls around Jericho fell down....
Joshua 6 : 20 (KJV)
So the people shouted when the priests blew with the trumpets: and it came to pass, when the people heard the sound of the trumpet, and the people shouted with a great shout, that the wall fell down flat, so that the people went up into the city, every man straight before him, and they took the city.
do the frequencies have a common denominator and are therefore setting up the standing wave in the same orientation, or are they all over the place meaning the standing waves are all separate?
I feel like matthias is going to make a scientific discovery at some point hahah
Are you planning on playing with Rubens tubes in the future?
Reminds me of a question posed in a linear math class years ago by the professor:
Can you hear the shape of a drum?
Nice standing wave jig! Try it with your siren?
Would using a square wave instead of sine give better results because of all the overtones?
That's friggin' remarkable.
could you get better vibration through the metal if you took the speaker out of the housing and placed it directly on the metal?
Tedium he could but he didn't want to destroy yet another speaker. (It's somewhere here in the comments)
I've been watching your videos a while ago, and I'm just a little surprised that you have so many new ideas about where to experiment. Now do you work with the sounds and waves? Congratulations to! Did not Nigel John Stanford's video give you the idea? If so, what's next? After many carpentry machines, you just do not do a jukebox like
Wintergatan? I look forward to newer videos and wish you a great deal more work! Keep it up! :)
Another thing that can be interesting is if you run a continuously changing spectrum of all frequencies from low to hight (or opposite).
Which spectrum analyzer app is that? I've been looking for a good one that holds the peaks like that does.
This is how you communicate with aliens.
Curious what prompted this exploration? ...application/implication or just basic science? BTW “basic” as in pure, not simple.
But, you could equally make those sounds with another piece of metal right? It doesn't need to be a speaker, it just need to produce the correct resonant frequency .... so you could make the sound mechanically right? With the right shaped piece of metal beneath the top one... maybe a metal guitar string? Can you direct the salt... say to the edge of the tray?
is there someway to measure material thickness and inconsistencies? The diagonal lines must mean some kind of difference, if the speaker would be placed in the center of the plate, shouldn't that give symmetrical lines transferring from the center then?
johan jönsson yes and now. Using this it would be fairly hard. The asymmetry we see on this experiment is most likely due to asymmetrical supports for the plate and therefore asymmetrical tension along the plate. While material thickness and consistency certainly affects the wave pattern, it would probably be hard to separate the effect from the effect the tension has.
Ah, Bessel functions! I knew they'd be useful at some point in my life...
i love your videos always very intresting
mostly audio stuff
and with your woodworking skills i'm sure that you can build better sounding and better looking speakers than what you use
maybe for a next project : )
The problem i can see with those sheets is the raised edge, that edge will resonate at a different frequency, which may counteract the main sheet freq in the harmonics, best to use a flat sheet..
Most use a direct contact transducer, probably uses less power to resonate the sheet.
Sparky Projects it does really matter because it will just have other characteristic patterns for having rims.
Yeah, the edges are just a boundary for the resonances in the middle.
no, the whole body has a natural frequency lol irregular shapes make interesting patterns
Hi Matthias, the link you have at the end of the video doesn't work. The file appears to be resonance.html not plate_vibrations.html
It would have been really fun to see a sine sweep. That is if you can come up with something to generate the signal. They are really cool to watch, as you can see the system as it passes through the fundamental frequencies.
Can you tell what software do you use, please?
What would be really neat is if you could vibrate concrete back into powder from its solid, cured state. I love this stuff.
Why did you replace the salt/sand between experiments
Do the resonant nodes map a wave of any kind or is it random depending on the shape of the pan?
What if you use both speakers & play 2 different (resonation) notes at the same time?
You could calculate the frequency by measureing the wavelength between the Sand/Salt "Dunes"
Is there a relation between the frequency and the number of "nodes"? And what about the frequency and where you hit it.
James Grimwood yes there is. More nodes on a standing wave means higher frequency.
This is pretty awesome!
Very interesting video, as usual! Thanks for sharing :)
Interesting, but I wonder what would happen at a frequency that was the lowest on the spec analyser.
Does you know the math side of this effect & why sand/salt curves never crossing?
If you'd sacrifice one of the speakers and make a coil affect the steel plate directly, You could go with less power and higher frequencies.
It's interesting how chaotic the modes look. If the metal was perfectly manufactured, you would think the modes would look more consistent and predictable. But inconsistencies in the metal allow these weird modes to show up.
The manufacturing process involves stretching the metal, which probably accounts for some of these inconsistencies.
What shape would a sheet of metal have if the goal was to get as few standing nodes as possible during a frequency sweep from 10 hz to 20 khz?
moelodin probably make it really small actualy
You should see what doing two frequencies or more at once does. Or try to match the the exact frequency of an objects resonance.
You could have seen the frequencies must better with an app which shows the harmonics not the spectre.
I don't know if there's an app for phone or tablets but I used them all the time when I was studying electronic music as a musicology student.
studying electronic music sounds fun.
I much prefer a graphical display so I get a better sense of what's going on. The frequencies I'm looking at are not harmonics of of anything either.
you can rebuild the speaker. wind a new coil. or do something else with it.
Fascinated, amazing art hiding in natures noises