 Welcome to the drum history podcast. I'm your host Bart van der Zee and today we're joined by Thomas Antoine in France Thomas welcome to the show Thank you, Bart and happy New Year. Happy New Year. It's it's great to have you here. This is um There's there's certain shows that are very unique because they're more like scientific and they're more They're about drumming, but they're they're really a little different than the the average, you know show about the history of a company so um Yeah, so today we're talking about the history of acoustics um and really how it relates to drums and um And all that good stuff which you have a background in and are kind of an expert on acoustics. So um that being said, why don't we hop right in and you teach us uh the amazing history of acoustics Okay, well, thank you for for hosting me on on this showbot and um yeah I have prepared some some some uh some kind of timeline talking about the the history of acoustics and and uh You'll you'll see by the end that that it's it's really um related to to the history of drums It begins at the same Time in history and the latest development are are really contemporary. So as our instrument is so um When you take a look at the other at the global history or history starts the sixth century bc and The ancient greeks and and namely uh Pythagoras Notice that the set of some set of strings with rational length ratio Would lead to pleasant sound that this was probably the first connection between an observation of a sound perception and Math and and and the geometry and the lengths of strings and things like that and then later on um Aristotle to to to a century after um Concluded that the sound would be about motion of air and there was you know A link between sound and motion and and then um Third century bc some academics assumed at the time that the sound would propagate Propagate like a wave with whatever perception we could have at the wave of a wave at the time Which would be a ripple on the on the on the top of a water surface on which you in which you throw a stone, you know and then uh probably for for wider structure the the the history of of uh architectural acoustic starts in 3000 bc With the epideurus theater, you know and and this theater happened to have the right slope the right spacing of benches And the right orientation and everything and the and the wall So that you know the sound of of a of a nectar could be heard from the stage to 60 meters away And which was with with an excellent intelligibility which was osam at the time and still is now, you know Sure. Now. Can I ask did they Probably a dumb question, but that was on purpose right like the position of the seats all of this stuff was at that point They had kind of figured out a little bit about Maybe started writing down like okay. This is where you put things to hear it or Sound will bounce like this like that was clearly done on purpose, correct Well, this is still being a research It's probably a by accident or a try and error thing But for sure this theater this epideurus theater had all the the good characteristic Characteristic so that the ancient Greeks would say okay Now we have this this geometry this this layout of theater and we're going to copy past all around the world I mean which which was was really done, you know, they had the right recipe to make a to make a nice acoustics Wow, so it's like it's like when you move into a studio and you're like It's just everything's perfect. You know what I mean like it might even be an accident Like you go into a room and you go wow, this sounds good or you know, wow, this sounds horrible Okay, so a big cement square room Maybe not great for acoustics, right? Like you kind of learned that so that's that's really cool. Yeah and and One of the particular thing about this theater is that the spacing of the bench Had really some effect in the propagation of waves of the in the integration of in the interaction of sound waves with with the with the matter, you know, and and this constituted A high pass filter actually And now, you know, it's still being researched, but we think that that the this this effect Would lead to to the to the good clarity because it would remove The low frequency To to mid low rumbling of probably the wind around or the background noise So the signal to noise ratio was really good, you know, naturally And what's really really even more Puzzling and amazing Is that today in the automotive industry and the space industry and and all the places where we want to do Noise and vibration control We are now considering Very new materials. It's still still in the labs. It's not really out now, but We call those materials Metamaterials or architecture architecture materials Uh, which have the the particularity of being very light for the amount of of sound reduction that they can bring And they show acoustic property that they should not have really naturally, you know, hence the term metamaterials But it's it's really about the their spatial organization The way that the patterns that that could be in some in some material that's going to lead to to to very interesting characteristics for for for noise and that's, you know from the bench spacing like 25 centuries ago, so it's it's uh, we when we're talking bench. Well, first off So when people hear a high pass that's also known as a low cut So if anyone's not as you know, hip to the terms that basically means you're you're cutting off Like thomas said you're cutting off all the low frequencies. So you can almost like in in audio engineering It's kind of if you have seen eq. It's like a You roll off all of these frequencies where there's particular Frequencies that are just like, uh, they're very rumbly like you said Like there's certain things that you just they're like almost inaudible below a certain frequency But like like there's there's also ones where you know that like like for me with voice stuff I always cut a little at 200 hertz like it's just there's particular things and then on another thought is That you said vibrations to where you think about like someone who has A subwoofer in their trunk, which I don't know if many people in france have are driving around with subwoofers They probably are but But how half the time though you hear just their License plate vibrating or you hear their their trunk shaking where It's that principle of like You don't want to hear the room shaking in in a theater. You want to eliminate all those vibrations Which is kind of a less eloquent way of saying what you're what you're saying But yeah, my question is is the bench placement You're obviously talking about the benches where people sit to listen to the performance, correct? Yeah, absolutely. Just making sure got it. Yeah. Yeah, absolutely and uh, uh The principle of those metal materials is just to to organize the matter So that they interact with the the organization of waves in in a very particular way You know, so so having benches spaced at a particular pace is going to to To impede very much some wavelength and in the end you'll get this this filtering effect So all the as you said all the the rumbling all the the can imagine in in a in an open air uh, greek theater All the maybe wind around or whatever background is coming Inside the theater is is is kind of removed and and you hear the voice of the actors with with claret And it's kind of neat too to think this is 3000 bc, right? This is like yeah, you're kind of like It's it's sort of to me like okay. They're starting to take the like entertainment. I'm sure they always have but like It's like it's creating the new industry of like Um actually taking acoustic serious and building theaters and Getting in that mindset and i'm sure i mean really it's kind of funny But like it's like the beginning of like like rodies and stuff. I'm sure and like like techs We're like, you know getting better at like setting things up properly and and stage hands So it's sort of like really early on them Creating these uh these spaces and creating that entertainment industry in a way Yeah, yeah, it's it's so they they they they understood that it was good for the for the performance for the intelligibility so so they they copied the formula around you know and and uh I think then nothing much happened for for for the for the next centuries and and in my knowledge the only the first room that was built For for for acoustics in the let's say more recent or modern world was probably the the auditorium in chicago, you know 1900 uh with selivan was or the architect and and the He designed a room. He took care of the acoustics of the room. You know, he made some some special device but before that Nothing much happened, you know Wow, that's a long time. I mean, yeah, yeah Yeah, and and you know from from from This date 300 bc to the enlightenment century. So 17 18th century There was of course musical activity and musical instrument crafting and development of musical instrument But the scientific interest for acoustics was lower than other other eras of science And when it comes to sensorial Uh analysis or or or or sciences The the the king was site, you know, so so the the the scientific effort were primarily oriented to site to understand how an eye would work and and uh You had at the time numerous progresses that were done in optics With the development of telescopes and microscopes and lenses and everything that were pulled by the needs of the astronomy and biology And so as I said, even medical sciences, we the the the doctors knew better about the eye Than they knew about the ear for a long time, you know, and this was just the way we are built We we think that that or or major sense is is is site. Mm-hmm Sure. Yeah, I think back to um God it must have been a movie or I can't remember which I hope was historically correct But it was and I have no idea what movie it was but almost like someone I I think it was like an a medieval like hearing aid where it was like a guy who was holding like a Horn up to his ear to amplify the sound And it went down and he kind of kind of curl curled and then he could hold it up next to his ear And I can't remember what movie it was but um, it's just that's an interesting, you know the The theory of and it's almost like if you put your hands behind your Ears and kind of cup around them. It actually makes it easier to hear things You know, so yeah, I'm sure people kind of learned that over Over time now. How does the you know, like the famous globe theater like the you know, shakespeare's globe theater that Is interesting and just the theory of all of this where again, you got to put it into perspective Right where people are sitting there watching a performance and there's no Obviously, there's no electricity I mean You probably wouldn't know this because you weren't alive, you know Yeah that long ago, but How crisp how clear would it have been to hear someone like Talking if you're, you know, 50 rows up in the in the the cheap seats like How good was it? I guess it was uh, you know Good enough so that so that people still are still talking about about authors today, but uh, but I guess Coming to room acoustics. It's it has been empirical for a long time You know, they're just like the greeks copied the things that work. It was really a try and error Approach because it's it's a bit like like in in musical instruments crafting, you know, what is good Of course when it comes to room, you could say, uh, I can measure the background noise I can measure the reverberation time and I I can monitor that because I don't want some Some some eco to be to be too strong And that's that's kind of objective values that you can get but but what what is what is right in this world does not really exist because you know, you've got this kind of a Magical thing of a particular room that's game. It gives the right sound and and I'm not saying that we don't know Why but but uh, yeah It certainly was not designed for this initially. It just it just happened It just happened sure and I'm I'm sure that And maybe this is a whole you know part of the conversation too is but like uh, but self mixing Like saying okay You know guy playing timpani or drummer of some kind in these, you know early time period play quieter Piano you play louder violin you play in the middle You know what I mean? Like I'm sure a lot of it was also like Uh If you can't hear the singer the or the you know the actor or whatever then you guys are playing too loud So play softer. Uh, that has to be a part of it Yeah, yeah, where do we go from there? Well, probably the next uh, the next stop is in 1600 with a galeo who Formulated the concept of resonance, you know and for I know that for musicians resonance means a lot of thing it's uh It's it's it can be uh the the lingering of of a particular note or or a particular feeling about an instrument But in physics, it's really the phenomenon where you have the the energy of a system that is oscillating Between the deformation of something say the tension in the string and the motion of this of the string and so Uh, uh galeo use strings and and and formulated, you know the the fact that at certain frequency there would be some particular Uh, uh motion or sub particular behavior of of string stretches And then a few a few years later mersenne Uh established uh that the sound intensity would decrease with the square with the the square of the distance So this is really really in the in the wave Fields of of physics and he made the first estimates of speed of sound. So we are around 1600 and um And then mersenne, uh really uh formulated the equation of vibrating strings So it's it's probably a bit a bit too too detailed, but but at this time to me acoustics made a step in the world of physics and fundamental mathematics and This is really the start of of acoustical engineering Because it means now that we have some design parameters that as a string construction and tension That are related to pitch and we have a mathematical backup for that So we understand how it works We understand that the string with more tension is going to have a higher pitch and we understand a string with a higher Uh Mass is going to have a lower pitch. You know those kind of stuff. Sure. So like Obviously like a base has thick longer strings and a ukulele has thinner higher strings. So there's um Got it. So to kind of clarify then so from 3000 bc up until the theater in chicago. We're talking there. That's like the room treatment acoustics But then when you get to 1600 with galileo, that's more of like acoustic like like you said pitch Uh, yeah jumps forward with that. Okay. Um, that's fascinating. Now, obviously drum history Are drums involved in this kind of thought at all or is this still very much string theory? For sure drums were played at the time, you know, there were some some drums having played, you know Since the beginning of of uh of mankind, but but uh, um Uh, if if we if we want to to If galileo would have worked on the drum, um, he would have found he would have found that the uh The the the the membranes show resonances as well, you know, yeah, and uh What's probably uh more difficult to to grasp is that the surrounding air With a membrane which is such a large vibrating surface Is is is is interacting very much as well, you know, um And and i'll make uh, uh, probably a parallel with with uh with uh automotive engineering for for noise and vibration when you want to understand what are the the The cavity modes which which are or like in a room, you know the standing waves or the the the the booming Effect in in in a room, uh, you have to understand what what we call the cavity modes. Okay, so so If you do that in a in a in a in a room then the you can assume that the the walls are rigid and they are not moving when you have a Standing wave inside the inside the room when you do that into a into an automotive vehicle, for example This is not true anymore, and it's the same for drums. So sorry for the for the long Oh, yeah, it's interesting or go around but but but uh um Often you hear people talking about the fact that you have the the the normal modes of the of the membrane Then you have the response of the cavity with with a kind of of my of of uh image of of uh the larger the the the volume then the lower the the resonance And they think about this in a in a in a sequential way But actually you cannot do that because in drums The motion of the head and the motion of the air around the head are very very strongly coupled And it leads to a fairly complex Uh problem that that Galileo at the time could not have solved. He didn't have the the uh, the right uh mathematical tool and the and the Not to mention any any measurement device to to understand understand this, you know Yeah, man. I I think I get it. I mean it's it's that is sort of uh, that's some Some next level stuff there, but like so the cavity is like like the the space correct like yeah like the actual Space like a cavity like an opening. Um Okay, well Uh interesting. I'm gonna try and let that set in here, but uh, okay So so 1600 so Galileo obviously and I I feel like you know Drums were drums like I I think it was more of a a lot of times in history. It's more string Related, you know piano and organ and harpsichord and all that they're not as much worried about the drums Yes, and one of the reason I think there are two two reasons one of the reason is that when you when you build an instrument that has a definite Pitch like a horn or or a string instrument You can have a quality Um reference for it. You can say I want the a to be 440 hertz exactly, you know And it's not the case for drums. You cannot you cannot say drums should be you know This this it has it has not a really definitive pitch Unless you talk about timpani and tabla Which are two to my knowledge the two head or or membrane membrane instruments that that show a really uh a strong sense of pitch And mind you the the reason for which A timpani can produce a note with four to five harmonics or partials that are exactly in relation with the other Is precisely because there's a strong coupling between the air in the cavity and the motion of the membrane if you take a membrane in vacuum, which is fairly often the kind of Of data that are shown when we talk about drums acoustics, you know You have those normal modes on the membrane with circles and and like pie Charts of of of where the the membrane is moving those are idealized membranes results computed In vacuum without air around when you add the air everything changes and it changes so much that um a membrane which would be In harmonic which would not show any any harmonic series when you put it on the on the Top of of a timpani volume. It becomes harmonic just from the coupling. Uh, so so i'm I hope i'm clear here. I'm i'm just telling you that the the It's a really a strong phenomenon that is probably um Difficult to apprehend certainly difficult to measure difficult to to uh to to to modelize But it's really what's happening in the drum. Yeah, no it's it's interesting too that you The whole like the thing about how the air affects it I mean that's just such a thing with drums and humidity and and heads and all that anyway and how it affects it and You know when it's cold that affects how long how far you can hear things and uh and and how sound travels faster and slower and hot and cold and um Really interesting it's it's difficult to understand but then again I guess it's I feel like once you could if you can see it And see these charts and kind of maybe see a video of it. That would be that'd be something cool to see but um Anyway, okay, so yeah carry on with the timeline here Yeah, so so so uh, I was talking about about vacuum and and the the effect of the air. Well, vacuum and atmospheric pressure was conceptualized in uh 1654 by a guy named Otto von Garicke and uh a few years later Robert Boyle Notice that the sound wave needed a media to travel and this media is air so, you know connections started to to be made between the Sound and and and the presence of of air um So then we we can we can move to the 18th century and uh, so the the uh enlightenment age had already started and uh although Acoustics are we're still considered a bit secondary. They would benefit in this century for major development John chore in 1711 built the first tuning fork Which meant that now we have a worldwide reference for pitch, you know a system for pitch And that would be exactly the same everywhere Uh and and by the end of this century uh Shalini a german Acoustician demonstrated with with his patterns Which are amazing illustration of the secret geometry of sound in structure I don't know but if you already saw those experiments with vibrating plates on which you would put Some kind of sand or very light material and that particular frequency the the the the sand or the dust would migrate to To the eras where there's uh no motion or minimal motion Yeah, and those areas you've seen that I've seen it where they lay like a piece of glass over like a speaker and then the with sand and it'll form like uh, you'll see the waves and and um It's I didn't know that went back that That for yeah, yeah, actually he he worked on violin and he demonstrated that some uh, uh some modes we call those those uh Simple motion or the motion that are leading to those patterns. We call them modes where We're contributing to to contributing to the sound of of violins and um modal analysis Had not started at this time It's it's a it's a mathematical tool that we know in noise and vibration We use very much to understand the the vibration of structure and and the response of of of cavities and in the drum business in my in my knowledge, uh, you got brands like noble and kulei in the u.s. And uh, uh, Yamaha, uh that have been uh claiming to attach their bracket at nodal point if you if you are familiar with that if you remember this Yeah, uh, it's okay. So so this is really about uh making a charlney pattern on a on a on a On a shell and finding the place where there is no motion and then you say, okay I'm going to to to to attach some mass or some some device at this location So I'm sure I'm not going to impede the vibration of this particular mode so a nodal point is a point on the shell where they have discovered that this point has no There's no vibration or minimal vibration at this point. And that's where they attach the hardware. Yeah. Yeah This is a well, of course, you can still, uh, you know, um, uh A single mode Is never you cannot you cannot have a structure vibrating Along a single mode. Uh, it's it's mathematically impossible You still you always have to get what we call residues of of all the other modes of the infinity of modes of the structure That that are that are in play, but you know in in particular situation If there's a frequency that you want absolutely to keep in the in the in the sound production Then you want to make sure that you're not impeding this this frequency frequency generation by putting the the the Some mass or some stiffness or anything at at the anti anti node, which is the the the the the space Where you've got maximal motion, you know and that has led to You know development of drums, um That that have minimal like free floating drums, um, where there's like, you know There's minimal or like the pv drums and uh, and we're going to talk about your drum brand repercussion later on but, um where it's it it actually focuses on that and um and that that hunt for the, you know Touching the drum as little as possible like the rims mount systems and things like that that just don't impede the The um vibrations. So, um Yeah, cool. Absolutely. You know, you as a percussion instrument the the the kind of signal input we we we put in a drum is is uh Something that contains uh a wide frequency range, you know a hit of a heat of a stick or a mallet Uh can can can can have a is fairly rich in terms of of a frequency range. So all the modes Uh, or many modes are going to to to get in play to in the construction of the of the sound. So saying, okay I've been I've been uh, uh taking care of one particular mode Can make sense, you know, but but what about all the others but it's it's uh, it's interesting to see that some companies are are are uh getting Acquainted or are interested in in in in this kind of analysis And then we we can move to to the 19th century because really, um Major developments for the modern acoustics took place. Uh in that century, which is so not not not that far away First of all, we have, uh, uh, joseph fourier Who developed the fourier transform. Are you are you familiar with that but I don't think so Okay, uh, actually, I I'm sure that that you and many of the of the people that are listening to to to us Have some some some sense of it because you already have looked at an an eq on on a on a Chart of eq of of a particular signal signal, right? What is it again here? Say what it is again real quick Oh, the fourier transform is is uh, is a mathematical transformation from a time signal So you like you take a sound signal you've got a sound pressure for example that is oscillating about An average value and and and you take this time signal and you transform it into A graph that is the amplitude of each Of the of different frequency components So you you have frequency as a x axis and you've got the amplitude as a y axis and we call this chart a spectrum Okay, and so so when you do an eq you want to look at the at the frequency component of the signal and the frequency components Uh, uh are are computed through this fourier transform So Is it basically then going to tell you where you're having like a build up of too many frequent of like Like it's too dense in certain areas of the frequency or is it more A like amplitude thing because when I hear like you said sound pressure, I think of like an spl Meter like like the sound level meter to give you like the volume of of you know The actual sound you're listening to the the amplitude of it like what is the What is the end result of that that makes sense? Yeah, the the if you imagine that the the main the main, uh, um Uh Thing that that that that fourier brought with this transform Was that he could go from the time domain to the frequency domain And reverse from the frequency domain to the time domain. What what he stated is that A complex signal such as the one that we are recording now Is really made of the sum of simple very very simple signals sine waves actually and With a mathematical tool you can go from one to the other and vice versa So so I don't know if you if you imagine the the power of what that means But but now we are able to go from time domain to frequency domain So we you can make a recording Uh of an audio signal and you can assess The frequency content on the on the on an ecu chart with it, you know, you can say I want to to boost this frequency or I want to cut this frequency because I got too much or I want to to remove some of it essentially It gave you the the ability to work in the frequency domain. Gotcha. So it's basically making It's like a graphic equalizer where you can actually see um And and I googled it just because I'm like as you're talking I'm like I just wanted to like kind of look at what a time domain is and it says on one of these Many kind of acoustic sites a time domain graph displays the changes in a signal over a span of time And a frequency domain displays how much of the signal exists within a given frequency band Concerning a range of frequencies got it. So it's x and y like a like a you know a graph basically time and frequency and uh Okay, and I should say too if anyone out there is listening and this is confusing This is confusing stuff, but it's really cool. Just to kind of like think about it and and uh, and I think thomas You're doing a great job of explaining it, but I just wanted people to know that like and I mean I work in this field of like doing audio stuff and and I'm It's it's let it set in You know for people listening. It's pretty advanced stuff, but I think this is fascinating. So you're doing a good job Thank you. It's it's uh, it's really something that is really essential and to be very frank and and after a most 30 year of noise and vibration engineering The the the concept in your mind of of switching from from time domain to frequency domain saying, okay If I got this kind of time signal if I got a let's say, uh A pure sine wave what would be the spectrum of it? Well, the spectrum would be just the amplitude of that sine at that frequency of that sine So I'll get just a line on on the spectrum and then if if I got a shock like like a a strike of a of a drum Drumstick what kind of signal I'm I am I going to get in the time domain going to get a high force Then something that is going to to go down immediately What would be the frequency content of that? Well, you know you you have to to do the The the the gymnastics in your mind of switching from one domain to the other domain But it's it's tricky as you say it's something that that you know Why for example, uh a transient signal such as a drum hit Would make sense to be represented as a sum of sine which are signal that are repetitive over time, you know Yeah, it's not it's not intuitive Is time domain then would then like is is that kind of like Attack decay sustain release. I think I have that in order. Um, yeah, yeah That is okay. Well that I mean those are time domain Musical Conventional data, you know, okay, and then I mean frequency domain is if the 30 31 bounder eq system That you you may use for for whatever reason This you are acting in the frequency domain. You say, okay, I want to to to low pass This signal. I want to high pass this one. I want to to to put any kind of Type of filter in my eq. You're working in the in the frequency domain. Got it. I think that Totally helped me and people usually know this but attack Is the boom the first hit of a is a the first hit of something the strike usually it's a big peak on the waveform and then um, the decay is when it goes down and then sustain is how long it lasts and then Release release is is obviously the kind of the the the and you can see that on synthesizers where it's like a quick release or a slow Or compression. They all have that that's that system. Um, just to kind of make sure everyone's on the same page But yeah, all right. I'm glad I uh struggled my way through that Uh You know, what's concept conceptually what what what is really important is to understand And there's many ways many areas in uh in physics where this happens Something that may look as complex as a waveform like the one you're recording Is actually the sum of very simple stuff But it's just a sum of an infinite terms an infinite infinite many Signs and cosines put together and you'll get to to to this waveform and similarly The the the vibration of a symbol if you could put an accelerometer or Measure the the the vibration of a symbol is going to look very erratic You know, it's going to to be very very strange periodic But you know, you you you have a hard time understanding what's inside it But it's just the sum of simple motion of of what I mentioned earlier with moods. Well the It's it's the same principle of superposition which which by the way Can exist only in a given Environment it works most of the time in acoustics and in musical acoustics But like for symbols that I just mentioned. It's not always a case far from it actually, you know, it's as you said It seems already fairly complex, but but it's just for us drummers It's just the beginning, you know, we have to go even further in in the in the Mechanical and mathematical description to get a grasp of what's going on, you know Yeah, which is ironic because most people think of drummers is just, you know People who just hit stuff, but there's a There's a lot more to it than that when you try to understand what you hit and what's happening when you when you when you hit something Then then you're talking about Really really advanced stuff really really it's it's as I mentioned earlier, you know The reason for which not so many if not no one got got really interested in in in the acoustics of drums It's first of all because as I just mentioned, it's complex. It's something that is really requires very recent techniques and And models and so forth and the second one is is Because we don't have a clear Quality objective. What would be the goal, you know for a drum? What would be what does does a good drum mean? Yeah, in other words, you know, whereas in 1711 the tuning fork was invented which kind of like you said which standardized the this is what we Use now whereas with drums that doesn't quite I know people I'm sure people out there listening saying like I tune my drums to a piano I tune to a pitch but I think you know what I mean like a violin is a violin like that's tuned to a specific note So interesting. Yeah, and you can you can range the or you can sort the quality of violin Saying this one has got a better harmonic content than the other. They have the same quality of pitch I mean the same they are exactly at the same pitch, you know But one one brings a other kind of of of harmonics and and it's claimed to be better So so that's that's another thing you can quantify and in drums you you cannot really do that No, yeah, okay so Second half of 19th century was was more more intense With people like Helmholtz Who developed spectral analysis with resonators he made kind of of If you're familiar with with the Helmholtz Resonance, I'm sure you are because actually all you have to do is empty a bottle of of beer And blow in the in the in the neck of it and then you've got this Sound, you know that that is coming out of the of the bottle when you do that Actually, you hit what we call a Helmholtz resonance. So Helmholtz constructed a number of of Bottles, I'm not sure it was beer at the time, but whatever And he tried to to he understood that for certain sound some of the bottles who start to to to resonate And then a guy named Rudolph Koenig Filled those bottles with flammable gas and set them on fire And then when he played this particular sound you had the the the bottle or the container that was excited That showed a higher flame. So here you have the first spectrum analyzer Analogic spectrum analyzer of history and it was no fire. Yeah, it was fire It was a hate the the the height of a flame that would tell you. Okay. It's it's coming from this Volume that is tuned to a 440 hertz 40 hertz. So the note that was played was 440 hertz Wow, man, that is so like heavy metal, you know, yeah, well, actually you'll find on on on on on youtube people playing around with propane gas into Into cylinders with with many holes and they would play with a specially prepared loudspeaker they would they would play with a standing wave in that tube and and and lit on fire all the all the Those holes that are exit for the gas and of course when when the the the the sound wave Matches some inner resonance of the tube then the the flame gets higher and you get very nice patterns There's even a guy who was done a 2d flame Sound analyzer Can't remember his name, but it's pretty awesome to Look at this because it's going to to to give you straight away The the understanding of spectral analysis and and and the and the fact that that sound waves are, you know pressure waves that are added to the pressure of the gas at certain spaces at certain places And and and increasing the flow of gas, you know, wow, I mean and I'm assuming the The relationship then to the amount to the air in the room and they use fire obviously because it's Uh, very visual, but then I'm sure how fire uses the relationship between fire and air You know that has to be something in there. I mean wow, I'm just like this is It's I'm sure at the time it's it's still as I said on look on YouTube because it's it's fairly Very visual and nice experiments But at the time, you know when when they were trying to understand the the phenomenon of of of sound waves and and everything It must have been pretty amazing experiment. It's it's so that was back in in 18 1866 Uh now before we move on can I ask you like so, uh, yeah Like a low frequency would create like a higher flame or a wider flame or would it be a lower flame for the Like for the low look, you know low to high frequencies. How would it look? well, if you consider, uh Different volumes filled with gas and you've got one You drive to resonance one of them with a with a sound wave that that is actually Putting into resonance the the volume you'll find an I think an equal height of flame Whatever the frequency now if you use a tube In which you have the the the the gas and you've got openings regular opening in the in the in the tubes Uh, if there's no sound basically you'll find all the flames at the same height but that's soon as you as you Turn on your speaker and add to the gas pressure the acoustic pressure that is given by the by the the speaker This acoustic pressure is going to get organized With the standing wave in the a standing wave in the tube And you'll see min and max and very nice sine patterns of way of of uh of flames Along the the holes of the tubes. So so, uh, it's not so much as Dependent on the frequency. It's dependent on the location. I see Yeah, unbelievable how how early that that was uh being developed. It's it's it's Wild to think of like what goes through someone's mind where they go. Oh, man. I bet fire could work, but it's it seems like it's really been um Progressively getting more and more and more and more, uh, you know, it builds on Everyone is just learning more from the previous generation. Yeah, and and yeah, it's it's just 150 years ago, you know, probably drums are now 120 years old And and this is just just about the same the same uh Ballpark, uh, sure the drums set. I mean, obviously drum. I know drums go back. Yeah. Yeah, drum set. You're right. We all know Yeah Okay, and then then the next event which is a major one for all the the the acoustician is uh, uh in 1877 Lord Rayley Issued a book named the theory of sound. So here we we were in a situation where the the phenomenon of of sound waves were Mathematically described and this was this is the other it's a it's a major step in the understanding of of of acoustics and uh The story goes that that Lord Rayley was suffering from some fever I can't remember what kind of condition he had but he was on on on a on a boat trip on the Nile in Egypt and and he You know suffering from fevers. He got his imagination Boiling and and and he came out with with uh, okay saying okay gathering all what I know and what I understand about about uh Sound and what has has been done before. I think the the wave equation for sound is this one and he wrote the first the first wave equations and um The same year so so we we got on one hand From a very theoretical standpoint a guy saying this is the physics of sound and the same year Thomas Edison made first recordings. So, you know, it's it's a it's a nice coincidence and uh That was that was uh 1877 and was that like the beeswax like the cylinder. Yeah. Yeah. Yeah. Yeah, and actually, uh 20 years before A guy named edward leon de martinville Made some recordings on paper recordings of sound on paper But unlike Edison. He was he was uh, uh unable to replay them But he was the first time that that we materialized the phenomenon of sound Which is invisible into something visible and Edison made it, you know Engraved into into the be wax and and and then made the the replay Which and then we have so the the first guy who did it which you said it very well nicely his name I'm not I'm not gonna butcher it. But so it was basically I'm assuming Uh sound going into a large horn that then the sound would travel down and vibrate a needle to visually represent the The sound correct. Yeah. Yeah, this kind of device. Yeah, absolutely So so it meant we had at the time the understanding that sound was of it was about the traveling of pressure wave inside Inside the the air at a velocity that is known now as as a speed of sound, you know, this is really the global finding at the time And so so we could start playing with the interaction of this pressure with with as you just mentioned with device around such as A membrane that would push a stylus or you know, other kind of of a device And uh, so this was 1877 and uh six years after that Emil Boulanger patented the the the tensioning system for snare drum that is still used today, you know with the with the lugs and and and and uh and tension screws And founded the duplex drum company in the 1900 And at the same time, you know, the the modern drum kit was born It's just you know for the sake of connecting the history with the history of our instrument Yeah, you got to keep it drum related, uh, of course always Yeah and then then in the 19th century and and uh, uh More precisely in the second half there was a bunch of of a revolution linked to computer sciences really Frequency response function with tracking filters. So those are But those those are the way to understand the interaction between A force on the structure, for example, and the sound emitted, you know what what If we want to to analyze that we need to have what we call the frequency response function frf between the two how many how many decibels of sound do you get for one Newton applied on this Particular part of the instrument those kind of of data This was 1961 not really not far away Then the the fast Fourier transform which which is an algorithm that actually dates back from from from gos probably A century before but at the time they didn't have any computer to to run it um and 65 was uh experimental model analysis and 68 and 60 67 68 Real-time analysis meaning that that we would start to understand the transience not only the you know the the continuous signal But the the transience and so and all the tools all the tools that I used worldwide Today for for the analysis of sound and vibration Which I mean every single thing I ever do like for work with audio. I run through an analyzer Basically because I mean I I didn't used to when I was kind of younger in my you know audio engineering days, but Basically, it's how you reproduce like Consistent sound like for podcasting like you don't want it to be like One is very very quiet. The next one's really loud and then I mean so that's just obviously for for the the actual like Volume which there's a bunch of ways to actually Uh register what quote-unquote volume is um Uh, but the analyzer it's cool to know that that's so that was kind of mid You said 1960s, right and on yeah when they could analyze cool Yeah, yeah, then you know it was all the revolution pulled pulled by by the computer science and the application to structural dynamics and and and signal processing so so what you mentioned like uh compressor limiters and and things like that were we're starting to get even I wouldn't I won't say better because we had analog system and still using them, you know, but but uh all the all the the the numerical treatment of numerical processing of signal had had really had really had a boost at at that time And and at the same time the really numerical acoustics With simulation software like software that are able to predict what's going to be the vibration of a given structure saying, okay, uh, if I make a drum head with this material that has this density and this uh, uh, uh module module of elasticity what are going to be the the the frequency response function what are going to be the normal modes and so forth And uh, what's going to be the sound radiation of this membrane if it's excited by you know, uh, a force at this location of this amplitude and so forth. This is What I'm telling I'm I'm I'm giving an example about drums. I'm sure that nowhere no one is making those kind of Calculation for drums. It's it's widely known for for for aerospace and automotive and and uh industrial, you know products and sometimes sometimes musical acoustics, so then that's probably because it's A hell of a lot cheaper to kind of just like produce drum heads and and I'm sure experiment with them and try I'm versus like so you would do that with like a car or with you know, uh, you know spacecrafts where you want to just kind of like, uh, run Uh, what it would maybe what like have the computer figure it out before you spend a million dollars designing it Absolutely, you know, it's it's a competitive world and and uh, we need to design right first time So we need to have the all the tools with all the knowledge Embedded so that all first designing that is the right one. It's it's really important I mean, I would be surprised if if drum companies didn't use Some system like that where they can run it and and check frequencies and and you know drum head companies Um to develop new stuff and symbols. Um, so I'm sure there's And and guitar everything. I'm sure there's some it's probably not as technical as uh, you know aerospace You know stuff, but yeah, yeah, we'll talk about that because uh In in my mind and to answer uh bluntly your question the answer is no There is no, uh, uh To my knowledge when you do a research about who makes really, uh, uh, research in in noise and vibrant in In the acoustics of of drums and cymbals and so forth. You'll find some stuff that are coming from from, uh, Uh Universities really researchers, but but those guys are not related or are not Maybe sometimes funded, but I'm not even sure, you know There is there is no budget from from all the major Drum companies to make anything in the in the in the noise in the field of Of acoustics engineering for their products So in in my mind, uh, when they when they talk about their Those drum companies and those cymbals company and head companies when they talk about, uh, rnd expenditure I think it's really about, uh quality production reduction of costs And and but but nothing for for really the acoustic quality which which is, you know Puzzling because we are talking about the musical instrument, you know, so so Yeah, yeah So there's been in the in the in the more recent history some some, uh, Encounters between manufacturers and science It's it's been fairly scarce in history But but there I think they are coming to be more and more frequent today And one of the reason is that, um, as I said earlier, it's objectively a very difficult subject when it comes to Drums, you know, because you're talking from instrument design. How should I design a drum? to a physical perception loop Especially for rnd because you you see the instrument you feel the instrument when you play it and you have the sound coming out of the instrument Which is uh, something that if you play the instrument, you're going to hear yourself Probably someone five meters away is going to hear something different and the engineers They are going to hear something different and so forth. So so saying I'm going to engineer all that so everybody's going to be happy is is is very complex if not if not, uh Impossibles, you know, yeah, that's the classic That's the classic like a snare drum doesn't sound great in the room But it sounds good in the in the you know in the control room when you're yeah recording or cymbals sound really dead But then the other room they sound good Kind of yeah, absolutely. Absolutely. And although, you know, when you when you As you said earlier, we are just people banging on stuff, you know, but but uh The the for drums and cymbals the mechanics may seem simple simple You just strike something and it makes a sound, you know, but actually you have to to reach pretty complex physics to to get Start of a grasp of what's going on really And I think as well that that musical instrument manufacturers They they don't feel the need for the for to go into let's say scientific development to to push Uh The development of the instrument as we see today, uh Again, I think they are they are doing some investment to rationalize the production lower the cost increase the quality And for drums, you know From from history that that actually the drum set was born Not from the push from manufacturer. They're really the need From from the musicians and for for the music at the time. So Music called in the end for a hi-hat stand and a bass drum pedal And larger symbols in jazz in the for jazz in the 30s, you know that the larger than the manufacturer could Could could manufacture. So it was a challenge from the music To the manufacturers at at the time And it's interesting to think about we're very like We make, you know drummers develop what they need You know out on the streets, I guess you could say and then the the brands kind of catch up and then Make what they need sort of yeah, yeah, so they are kind of uh of followers of of of of the need Of of of musician of enough music, you know, yeah, then one of of the question you could Think about is is should the musicians know about all the Fourier transform and and the model analysis and And the science of their instrument in the end and to to some extent my answer is yes They should because they have to make, you know, the best educated choice in a very competitive environment so so they better know what what tools of the trade they need to to to get to their to their goals and and I think as well that that We should go from a situation where the music pulled the need to The manufacturers or or Innovators are bringing to to musicians some new way of of expressing themselves I think today there's a confusion in the drum business particularly between new And innovative, you know with a very heavy tendency to look back in history. I live in france. I can tell you that Companies like asba is starting up. I'm very glad with that. It's great. You know, it was a it was a great Great drum brand in the 70s but actually It's just looking back in the in the rear of your mirror and saying we're going to just to to reborn from from our ashes and and Many many the value of of old brands is so high, you know a great Stingerland. You name it But in terms of of innovation those brands were very very innovative at the time I mean when great drummers made the history of our instrument They were probably using instruments that they found very innovative at the time Why do we have to copy them today? I mean to copy those instruments today. That's a great point. Yeah You know, we should we should be able to bring something as new as it was at the time We should be able to to bring something New for for for the drummers and for the for the musicians, you know, you have to Yeah, that's come up in some way shape or form on the show a bunch where it's like, you know, really after Obviously things came out where it's like, oh now there's and I'm thinking like tomma where it's like now There's the gong bass drum or octabons like things like that come out which are Tools to use but like really the the The formation of the drum set hasn't it hasn't changed that dramatically in in a long time where Yeah, there is a tendency to look backwards and a lot of nostalgic Feelings towards the old drum set and I'm kind of I mean, this is a history show. So Yeah, of course I'm going we all as drummers love our, you know, looking at trap sets and all this stuff, but But you're right. I've never thought about that that that was also innovative and Slingerland was pushing the envelope and using radio frequencies to make shells and and But nowadays, I mean, there are a lot of newer brands who were pushing the envelope forward such as, you know yourself, but like Obviously, there's some some big big big brands who are doing it too, but but there's still the legacy You know, we love our, you know, oh my god, Slingerland's coming back kind of thing and it's uh, rogers is coming back We love our legacy brands. That's that's that's for sure Yeah, you know, I own a too old gretch set and I'm not going to depart from them You know, you don't get me wrong. I'm I'm into that of course as well I like the the soul of those instruments But but uh, you know, the what is really new for the drummers today I think we need to keep the momentum of progress and innovation that those great people started not so long ago, you know, and Uh Well great drums made great drummers, but great drummers will make even better drums if they are given the mean to do so and and and in order to to differentiate a new drum from an innovative Innovative drum in my view in my mind and in my activity It's really this scientific approach that should bring not everything but some new things to the table saying, okay We we can further the the understanding of the of the of the way the instrument work and we can make new proposals Is that better? I don't know. It's just new. It's for the the the artist to choose, you know to me Choosing an instrument is is an artistic move. It's really okay I'm going to select this snare because I want this sound and this is a way I want to express myself in this context It's you know, and we have to widen as much as possible the the array of of possibility for artists they should not be artists should not be constrained by What comes actually from a consideration of Industrial production and cost control and and so forth Yeah, absolutely, which goes back to the same of you know, we create what we need and then the companies kind of follow so You know, I think it's it's over. We're overdue for some some really new cool modern changes But I think again, like I said, there's there's companies doing it out there Which I I do want to get to talking about your company here But as we get close to the end here, why don't we push forward with the history of the acoustics? So we were in like 60s 70s outboard gear Working on all that. Where did we go from there to get to to modern? Well, I wanted to to give you actually as we we got into the discussion of musical acoustics and and and drums Uh, I just wanted to to to make a side note of what's going on today about acoustics and musical instruments And I have three three examples that I put together Or are coming to my to my mind And the first one is the the story of ovation guitar if you I'm sure you're familiar with them And the story is it's really simple. You've got an engineer Charles Kamman There is a passion has a passion for guitar And he just asks his team of engineers that are aerospace engineers to say, okay, just understand how it works Well, make me a new guitar make something new, you know, and the guys go engineer way They want to understand how it works and they want to to to remove what's what's wrong and to enhance what's right, you know, so so And I'm not saying in the end it's it's it's just the way it's better, you know, it's just the way it was done and and, um Uh They made something that is what I call wisely different In the case of of they they understood the the role of each part and the sound board and and the and the volume behind and and everything And they created an instrument of which, you know, the the reputation today, you know, it's it's uh I'm sure some people hate some people like but but for sure it's it's it's new, you know Yeah, with the rounded back and that's interesting to the point of some people love it some people hate it So even if it's the most innovative best thing sonically Someone might go no, give me my martin guitar. I don't care about that weird-looking Absolutely But the the point is not to to say Because I made some engineering on this instrument It's going to be better The point is to say because I made some engineering of the on this instrument. I understood it work and I could make some Wise choices and have a new proposal for you. No, are you going to to consider it? Are you going to to say it's it's good for what you you want? That's another story But for sure I got something new to to to propose, you know, sure love it so the the second example is is a fairly uh infamous experiment that took place in paris Under the leadership of dr. Claudia fritz in uh 10 years ago And it's you can you can google it. It's the paris double blind experiment. It's about violin And I can tell you it this was a passionate passionate subject and is still the case because what Claudia fritz did she's she's a an acoustical expert doctor in in acoustics And so so she gathered a number of garnieri and and stradivari With all the top soloists of the world And so there was a list of 17 Violin Half of them were, you know, world renown legend of stradivarius and and and garnieri and the other were modern production of of Today's makers And in the end of the so so so the top soloist would play All those violins in various environments. He would listen to the other You know, it was all crossed in In all the in all the ways and it it was a double blind experiment meaning that that the Soloist that would play a study values did not know could not see that he was playing a study values He could hear it. He could feel it. He could play it and then he could listen to his peers Playing this violin, but not knowing what it was, you know, and in the end it just showed that actually The those top renown soloists best in the world Unable to make the difference just from the sound standpoint between study values and modern production So I can tell you I think claudia fritz is going to have a hard time working in in In shops where they say well or in places where they are study values today because it's been so passionate Subject but but really what I think what's interesting is that, you know So modern manufacturers of violins do not do not not have to to to live in the shadow of those huge Mythical brands such as study values, you know So to me from from even from a business standpoint, it's a good new It means that the those guys are making violin At the best of their art and it's the same as as the worldwide reference So so it's it's it's a it's a good result. It's it's at least it's a very interesting result And the latest example, I want it's more modern. It's more recent. It's uh, I'm still french I'm sorry. It's it's very it's very french stuff, but uh Very interesting company that I I met across the acoustic all acoustic labs where I used to to work Uh, that company is named seos and it's it means shape your own sound And those guys are 3d printing some saxophone and clarinet mouthpiece with the Sound tailoring in mind meaning that you play saxophone. You want this kind of sound You just fill in on their website the the the kind of sound you're looking for bright dull I I don't know. I'm not a saxophonist, but you get a number of script of descriptors And in the end this actually would would would would set a CAD program to modify the the geometry of of the mouthpiece 3d print print it and send it to you and and and it's amazing. I mean and it's all based on the understanding the the people that have Made this company are specialists in in uh in acoustics and particularly in in uh saxophone acoustics And it's uh, it's great. I mean it's it's it's really a nice gathering between Modern technique 3d printing understanding of acoustics And and and musical instruments. Yeah, and that seems like it could transfer over to the drums In some way, I mean, you know where it's design your You know 3d printers aren't going away and I know that people have 3d printed drums and that's kind of a popular thing, but um It's 3d printing is not going anywhere. I know my dad who's you know, 59 3d printed at a library a little piece to fix a uh antique shelf that was missing like a little very specific washer He just took the old one in measured it put it in boom it fits perfectly and it worked No problem. So when you know that you're You know almost 60 year old dad can do it. It's pretty popular Yeah, yeah Yeah, so you know, it works today for for for a saxophone and mouthpiece for drums Yeah, probably things are going to come up because You can make very intricate shapes and and and uh, the question is of course, what kind of material are you going to to be able to print And you know, there's all the metal printing stuff that is coming up with with parts that are actually uh Structurally could yeah There's a german guy who 3d printed a whole Jet engine, you know for for a for a model plane and it works. So so you can make structural parts now Oh my god, I love that those three or those are great examples and I mean it's Every single one is very uh, it fits to drums where you think that it sounds a certain way because it's old and I love the like blind taste test stuff with that but um Okay, so for the for the sake of keeping the episode, you know in in some timely Manor let's let's wrap up here and I want to hear about so first off tell people about your company repercussion And then um, which is sound tailoring. It's kind of your big thing Yeah, and where they can find you and we'll we'll go we'll call it up a day after that okay, so, um I founded uh Repacution four years ago and it all started with a consideration on the interaction of air with the vibration of Of the head, you know as I said before it's essential for the sound of timpani So I say why not for the snare drum and the other drums, you know And and what is the role of venting? What what's really going on you see tons of people are testing a lot of shapes and openings and uh as well some research of the of the of a symmetry in the instrument and and this led to a really innovative design that I patented that that allow that are today allowing me to provide drummers with what I call sound tailored snares meaning Beyond changing the head tension the head types or the snare wires I can really change the the sound of the instrument through The the the the shares and the and the aperture and the characteristics of the of the vent and everything So so because you have to have in mind that in a drum 90 percent of the sound is made by the head and the way the head vibrates and the way the high vibrates is very much influenced by the behavior of the what I call the acoustic circuit meaning the Volume of the air all the drummers know that the dimension diameter and depth are a major Player on the on the drum sound but you have all the ways of of tackling this or you know Introducing some new independent parameters of that and this is what I've done in tuning the acoustic circuit they start to to be of the sound that is that is Needed by by some particular drummer And then then I have a selection of shell that I mix and match so I can make hybrid shares hybrid drums with a Metal and wood and acrylic acrylic whatever is needed really for the for the for the sound and So now I have developed a number of snare drums and tested them I measure the frequency response function of all my awful of my of my shells to to to to know where I'm I'm going And I just just developed Two full drum kits using the same system. That's that sound really awesome really really I'm blown away by by the sound of those So there's further development to to come always With a lot of of innovation I'm thinking a lot about hybrid electronic acoustic drums Uh, which would be actually a phase two of what I've done 10 years ago in in the past for for electronic drums So, yeah, there's a lot of things that are that are coming coming up and uh, all all this uh, this work has has been uh has been Developed after hours in in the lab and made prototypes made calculation and you know ready engineers the the the drum so And you know, it's not about in the end. It's not about developing a scientifically wise technology because it doesn't mean anything in in the artistic world As I said before it's about proposing the new field of possibilities to artists And as I said, it's very important to me all the the development of repercussion. It started day one I made my first prototype and I went to to the to the uh, uh, auditorium with classical percussionists I said look, I got this new kind of drum. What do you think I went to those guys because I know they are very very, um attentive to sound, you know Uh, and so so so I I always have the the the feedback I'm always working and always developing with with a some short feedback look of artist playing It's just not me going around with scientists scientific stuff that would lead to nowhere It's really about you know getting the feedback of of people and I have I'm I'm foreign at enough and very happy to have the feedback of of we know the world we know the artist Testing and using my my drums and are very happy with that. Well, that's just awesome I mean, it's it's um, it's like you said with ovation guitars. We were like, well Like mathematically and scientifically it's perfect, but someone might say I don't like it Yeah, it's good. Of course Because like you can be in as a lab as much as you want But like like you said, it's good that you're actually getting drummers feedback and and they're beautiful drums with a very unique obvious uh system if if if you guys out there listening go to repercussion re P e r c u s s i o n repercussion dot f r Um, you can see um and see this really cool technology. Um the thomas has been doing um and God what I love about it though is just that Obviously you're a uh, dare I say brilliant guy with with all of this understanding, but um It it's cool that a guy like you is out there making this stuff to push forward the development of the drums For a number of reasons, you know to be because it it needs to we need to move forward and and there's nothing wrong With what's going on now, but I think it's great that someone like you is using you're using your powers for good and not evil And you're you're using it for drums Thank you very much bot. Yeah, absolutely. Well, thank you for coming on the show and uh, it's so cool. You're my first Uh, you're my first french guest. So from what I from what I hear there's there's a lot of cool stuff going on in france with um uh acoustics and experiments and all kinds of cool stuff so i have to Get some more some more french folks on the show, but uh on that note Everyone can go to repercussion dot fr check out what thomas is doing. Um So thomas, thanks for being on the show my friend. Well, thanks for having me bot If you like this podcast find me on social media at drum history And please share rate and leave a review and let me know topics that you would like to learn about in the future Until next time keep on learning This is a gwin sound podcast