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• RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. - Michael Koster 08:21:03 03/21/12 (5)
  In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by Tre' on March 18, 2012 at 14:14:53

  Now I know you be messin wid us!
  
  A sine wave is a rotating vector. It has no starting point or end point.
  
  Then you say that all sounds have a zero starting point...
  
  How can a thing have no starting point and yet have a starting point?
  
  Tre, did you ever study a subject called "AC physics"?
  
  Just sayin...
  

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  • RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. - Tre' 14:13:02 03/21/12 (0)
    In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by Michael Koster on March 21, 2012 at 08:21:03

    Maybe I should have said "All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of multiple waves that resemble sine waves".

    Is there a problem with Fourier?

    "Any waveform can be analyzed as a combination of sine waves of various amplitude, frequency and phase."

    Tre'
    Have Fun and Enjoy the Music
    "Still Working the Problem"
    
    

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    Edits: 03/21/12
  • RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. - Michael Koster 08:30:47 03/21/12 (3)
    In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by Michael Koster on March 21, 2012 at 08:21:03

    Also, what's the point?

    Are you making the claim that any amplifier that can correctly reproduce continuous sine waves over the human hearing range will sound the same as any other amp that also has the same frequency response (distortion, etc.)

    That there is no element of dynamic response?

    Really? It's all sine waves, all the way down?
    

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    Edits: 03/21/12

    • No (nt) - Tre' 14:03:29 03/21/12 (0)
      In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by Michael Koster on March 21, 2012 at 08:30:47

      .
      Have Fun and Enjoy the Music
      "Still Working the Problem"
      
      

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    • Way to GO Michael !!! - drlowmu 12:12:40 03/21/12 (1)
      In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by Michael Koster on March 21, 2012 at 08:30:47

      Mr. Bob Fulton used to call the music frequencies "EPI"s which he said stood for "events per instant". Not bad at all description, is it ?? He wrote a paper on it.
      
      He measured a Trumpet at 80KHZ, and a Harp at 110 KHZ, using conventional terms.
      
      Bob was using his own 2 GHZ TEK scope back in the early 1980s, to view audio.
      
      Jeff Medwin
      

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      • RE: Way to GO Michael !!! - Michael Koster 17:02:35 03/21/12 (0)
        In Reply to: RE: Way to GO Michael !!! posted by drlowmu on March 21, 2012 at 12:12:40

        Events per instant is a poor definition really, because there is no quantitative definition for an instant, nor for what constitutes a musical event.
        
        Certainly the surfaces of these musical instruments are capable of vibrating at these frequencies. The limitations of microphones, loudspeakers, and human perception suggest practical bandwidth limitations in the 30-40 KHz range at most.
        
        But I'm thinking more about the question of whether the continuous sine wave response of an amplifier tells the whole story of it's sound when reproducing music. One could always do continuous testing at 80 KHz or 110 KHz or 2GHz or whatever but is that all there is to know?
        

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• RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. - 6AS7_6SN7 12:50:49 03/20/12 (1)
  In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by Tre' on March 18, 2012 at 14:14:53

  Or whatever set of orthonormal functions as well, as sines & cosines are not the only useful functions for decomposing audio signals.
  
  In signal processing terms, a function of time is a representation of a signal with perfect time resolution, but no frequency information, while the Fourier transform has perfect frequency resolution, but no time information.
  
  The magnitude of the Fourier transform at a point is how much frequency content there is, but location is only given by phase (argument of the Fourier transform at a point), and standing waves are not localized in time – a sine wave continues out to infinity, without decaying.
  
  This limits the usefulness of the Fourier transform for analyzing signals that are localized in time, notably transients, or any signal of finite extent.
  
  As alternatives to the Fourier transform, in time-frequency analysis, one uses time-frequency transforms or time-frequency distributions to represent signals in a form that has some time information and some frequency information – by the uncertainty principle, there is a trade-off between these.
  
  These can be generalizations of the Fourier transform, such as the short-time Fourier transform or fractional Fourier transform, or can use different functions to represent signals, as in wavelet transforms (mostly used in seismic analysis) and chirplet transforms, with the wavelet analog of the (continuous) Fourier transform being the continuous wavelet transform.
  
  Best Regards
  Luca
  ecc230
  
  

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  • Thanks Luca as always a very coherent response... - Minussss3db 23:45:08 03/21/12 (0)
    In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by 6AS7_6SN7 on March 20, 2012 at 12:50:49

    Mr. Gusser, reading Luca's posts would be a good experience...he very competently models vacuum tube circuit response spectra...makes valid design decisions on this basis, and then measures the end physical circuit response spectra and carefully compares to the model...
    
    Much more methodical...unlike cut and solder me...hehe...
    
    Anyway he raises our collective awareness... if we look into audio measurements probably the most advancing measuring we do generally is simple impulse response, (which is basically a form of single frequency wavelet transform)....
    
    so you are wanting to see measurements of "Magic Wires"....actually I don't of course believe in Magic Wires...hehe what I have had is a listening experience of wires which are "Crap(Bad)" and wires which are "Good". (i.e. copper, silver, tin "Good"...Steel, Nickel, Lead "Crap"(Bad))
    
    so I have been thinking about " Transfer Efficiency" and of course this is really a Power Distribution term, but what I do think of in terms of any audio system, is actual "Tranfer Function"....and I am looking for input to be the same as output...i.e. for Unity gain to have the Transfer Function equal to "1" for all frequencies, and all misc phase functions equal to Zero....so for "Good" wires I could propose that this is the measurement definition of what a "Good" wire is...i.e Transfer Function equal to 1 for all frequencies, say to 200khz, and all phase terms have a constant delay term, and all frequency dependent phase changes (i.e. derivitive of phase delay "group delay") be equal to zero for all frequences up to 200khz....
    
    anyway this already too long...bottom line I am just curious how the Kimber people measured the differences in black wire vs other colors???
    I suspect it takes perfect parallelogram tiling of the time–frequency plane, using the method of multiple mother chirplets.
    
    2nd bottom line: I am unequiped to measure chirplets...question Mr Gusser? Are you equiped to measure chirplets?...because I think this would give us an interesting comparison of the various response functions of the various wires...
    
    So anyway have Fun, and All for Good Music..
    -3db
    

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• I am afraid I'm strongly with the first responder - It's an abstraction - Timbo in Oz 21:24:00 03/18/12 (3)
  In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by Tre' on March 18, 2012 at 14:14:53

  It's like saying teh the earth is 'round-ish) or quoting one of Netwon's laws.

  What human's pay attention to with musical notes might be a far more useful approach, especially when we are talking about reproducing rarefactions and compressions in air, don't you think?

  Is air linear in compression and rarefaction? Are speakers!?

  Do you know what human's care most about with a musical note, as it happens in real time?

  There are three basic components. Start, middle and end.

  Remember that lots of notes have only the beginning and the end, some instruments can only do those two, and if an instrument that can do a middle bit or not is recognisable when a note doesn't have it, then the middle bit probably doesn't matter a whole lot. Yes? And that's the only bit that approaches a sine wave.

  Try again?

  
  Note that a post in response is preferred.
  
  Warmest
  
  Timothy Bailey
  
  The Skyptical Mensurer and Audio Scrounger
  
  And gladly would he learn and gladly teach - Chaucer. ;-)!
  
  'Still not saluting.'
  
  
  

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  Edits: 03/18/12

  • RE: I am afraid I'm strongly with the first responder - It's an abstraction - Tre' 14:15:02 03/21/12 (2)
    In Reply to: RE: I am afraid I'm strongly with the first responder - It's an abstraction posted by Timbo in Oz on March 18, 2012 at 21:24:00

    "There are three basic components. Start, middle and end.
    
    Remember that lots of notes have only the beginning and the end, some instruments can only do those two, and if an instrument that can do a middle bit or not is recognisable when a note doesn't have it, then the middle bit probably doesn't matter a whole lot. Yes? And that's the only bit that approaches a sine wave."
    
    Could you explain that again? I have no idea what you are talking about.
    
    Tre'
    Have Fun and Enjoy the Music
    "Still Working the Problem"
    
    

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    • RE: I am afraid I'm strongly with the first responder - It's an abstraction - Timbo in Oz 14:38:40 03/21/12 (1)
      In Reply to: RE: I am afraid I'm strongly with the first responder - It's an abstraction posted by Tre' on March 21, 2012 at 14:15:02

      The attack or starting transient - fully characterises the instrument and carries most of the player's expression and individual tone.

      [If we swap attacks from one instrument's note to another instrument, listeners will identify the attack instrument as the instrument.]

      For many instruments - piano, harpsichord, and percussion, this is followed by the decay. They can't do a continuous tone. If we remove the decay of any instrument, it turns out to be the second most important in identification.

      Some instruments can do a continuous middle bit and yes there are harmonics on that, but this part is the least significant in identification of an instrument.

      So much for the standard definition of characteristic timbre which needs to be modified.

      Beginnings and endings are where it's at.

      I was a chorister from age nine, and began soloing by eleven, and one of the sayings has stuck with me - 'If you can't pitch, you can't pitch.' You have to begin right.

      All of this has been known since before stereo.

      So the ability to launch a note correctly, and transient response are vital to fidelity. Funny that silly old tubes sound kinda right to me.

      Fourier is a marginally useful and reductive abstraction. Reductivism can blind us to the target whole.

      Hi-fi has to coherently reproduce the leading edges of notes - rarefactions and compressions, sharp positive going 'waves'. And, not add/subtract more reflections than in the originals that reached the mikes.

      Diffraction at the speakers is more destructive than most people suppose.

      
      
      Note that a post in response is preferred.
      
      Warmest
      
      Timothy Bailey
      
      The Skyptical Mensurer and Audio Scrounger
      
      And gladly would he learn and gladly teach - Chaucer. ;-)!
      
      'Still not saluting.'
      
      
      

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      Edits: 03/21/12

      • Thank you (nt) - Tre' 16:32:14 03/21/12 (0)
        In Reply to: RE: I am afraid I'm strongly with the first responder - It's an abstraction posted by Timbo in Oz on March 21, 2012 at 14:38:40

        .
        Have Fun and Enjoy the Music
        "Still Working the Problem"
        
        

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• Are Triangle waves and square waves made up of sine waves? - Chris O 14:39:56 03/18/12 (8)
  In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by Tre' on March 18, 2012 at 14:14:53

  I kinda thought sound was simply a disruption in a medium.
  
  
  
  

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  • RE: Are Triangle waves and square waves made up of sine waves? - Eli Duttman 17:33:07 03/18/12 (0)
    In Reply to: RE: Are Triangle waves and square waves made up of sine waves? posted by Chris O on March 18, 2012 at 14:39:56

    The answer is yes! Fourier's Theorem states that ALL periodic functions can be stated in terms of the sums and differences of sines and cosines of the fundamental and its overtones.
    
    In the case of square wave, lots of high order overtones are needed to firm up the wave's corners.
    
    "Sharp" waveforms contain harmonics of the fundamental that extend into RF. That's why I suggest a "hash" filter made from a high current RF choke and a mica or NPO ceramic cap. in PSUs that employ large value cap. I/P filters.
    
    Eli D.
    
    

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  • yes - Tre' 15:07:07 03/18/12 (6)
    In Reply to: RE: Are Triangle waves and square waves made up of sine waves? posted by Chris O on March 18, 2012 at 14:39:56

    .
    Have Fun and Enjoy the Music
    "Still Working the Problem"
    
    

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    • " made up of sine waves " - FenderLover 17:42:40 03/19/12 (5)
      In Reply to: RE: yes posted by Tre' on March 18, 2012 at 15:07:07

      Chris, Tre', Timbo, Eli, et al... From what I recall from Physics 101 (many moons ago), music or speech or anything complex & periodic in nature can be described by folding or mathmatically summing up a series of simple sine waves. The more approximations you do (summing up more sine waves that, when added, the closer you get to the describing the actual Natural periodic event. You can never get 100% precision, even with say, a regression formula of infinite trials.

      Sound or music is not "made-up" of sine waves. But, are described or approximated by a series of unique wave function formulas. It is the way one can get a handle on this extremely complex phenomenom. Describe it in a formula--- so that the music can be reproduced--- in a somewhat faithful manner (at least as precise, as the least accurate component wave).

      Sorry, about all the yaddy-yaddy-yaddy.
      

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      Edits: 03/19/12

      • Yes I covered Fourier in my 'mid-life crisis degree' - Timbo in Oz 04:35:40 03/21/12 (4)
        In Reply to: RE: " made up of sine waves " posted by FenderLover on March 19, 2012 at 17:42:40

        during it I became an academic, temporarily.
        
        My point is that it's not very useful in looking at music reproduction in the home.
        
        Basic? yes.
        
        
        
        
        
        
        Note that a post in response is preferred.
        
        Warmest
        
        Timothy Bailey
        
        The Skyptical Mensurer and Audio Scrounger
        
        And gladly would he learn and gladly teach - Chaucer. ;-)!
        
        'Still not saluting.'
        
        
        

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        • RE: Yes I covered Fourier in my 'mid-life crisis degree' - drlowmu 12:14:29 03/21/12 (3)
          In Reply to: RE: Yes I covered Fourier in my 'mid-life crisis degree' posted by Timbo in Oz on March 21, 2012 at 04:35:40

          My mentor in audio, Mr. Bob Fulton, scoffed at Fourier.
          
          Jeff Medwin
          

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          • Possibly at his misuse or overemphasis by others? - Timbo in Oz 14:17:07 03/21/12 (0)
            In Reply to: RE: Yes I covered Fourier in my 'mid-life crisis degree' posted by drlowmu on March 21, 2012 at 12:14:29

            Because his work is pretty hard to wriggle away from.
            
            
            Note that a post in response is preferred.
            
            Warmest
            
            Timothy Bailey
            
            The Skyptical Mensurer and Audio Scrounger
            
            And gladly would he learn and gladly teach - Chaucer. ;-)!
            
            'Still not saluting.'
            
            
            

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          • RE: Yes I covered Fourier in my 'mid-life crisis degree' - DanK tubes 12:42:12 03/21/12 (1)
            In Reply to: RE: Yes I covered Fourier in my 'mid-life crisis degree' posted by drlowmu on March 21, 2012 at 12:14:29

            Wow, he scoffed at a historically famous mathmatician/physicist who's work from 200 years ago is so important that it is still used on a daily basis by scientists and engineers. This Bob Fulton must be quite a guy. I did a search on the ISI Web of Science citation index and couldn't find any papers by him and his ideas of Events Per Instance [EPI]. Google schollar didn't turn up anything either. Perhaps you can share his work with us. It must be fascinating.
            

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            • Sharing Bob Fulton's work....... - drlowmu 15:14:09 03/21/12 (0)
              In Reply to: RE: Yes I covered Fourier in my 'mid-life crisis degree' posted by DanK tubes on March 21, 2012 at 12:42:12

              Yes, I would have to find my "Events Per Instant" article and hand type it into a re-usable format. There is also a GREAT article he wrote called "Those Funny Little Wires" - about wire for audio, marvelous, that I personally think should be retyped and posted up here on this Forum.
              
              There is an Electronics Engineer in Florida who has been prepping a web site, dedicated to the memory and work of Bob Fulton, but the site's opening seems to be always getting delayed.
              
              I may, or may not, re-type that material. It will show up one day, but I can't refer you to it on line "today."
              
              Point well taken about Fourier. I have to tell you, Bob was VERY dedicated to audio, and smart. Also, being a musician, recording engineer, choir director, and trumpet mouthpiece maker, he brought many positive qualities to the subject of audio. No one fills his shoes in audio for me since he died in 1988. Sorely missed.
              
              Jeff Medwin
              

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• Not really... - op48no1 14:39:14 03/18/12 (1)
  In Reply to: RE: All sounds, from the screech of nails on a blackboard to a symphony orchestra, are made up of sine waves. posted by Tre' on March 18, 2012 at 14:14:53

  That is just a profoundly useful abstraction.
  

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  • RE: Not really... - Michael Koster 08:03:52 03/21/12 (0)
    In Reply to: RE: Not really... posted by op48no1 on March 18, 2012 at 14:39:14

    Posts: 139
    Joined: October 29, 2010
    That is just a profoundly useful abstraction.
    
    +1
    
    Sine waves are all about continuous
    
    Music is all about discontinuous
    
    ;-)
    

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