Welcome!
Just a few a ground rules first...

Promotion, advertising and link building is not permitted.

If you are keen to learn, get to grips with something with the willing help of one of the net's original musician forums
or possess a genuine willingness to contribute knowledge - you've come to the right place!

Register >

- Close -
Page 1 of 2 12 LastLast
Results 1 to 15 of 24

Thread: haha Shredding as fast as the speed of sound.

  1. #1
    Registered User
    Join Date
    Oct 2006
    Posts
    23

    haha Shredding as fast as the speed of sound.

    Sort of a silly question, but can anyone figure out how many notes per second you'd have to pick at in order to create and 'out-of-sync' effect between what you hear live and what you see?

  2. #2
    Registered User
    Join Date
    Sep 2007
    Posts
    252
    The answer is, what you hear and what you see are always out of sync, just not a noticeable amount. Due to the fact that the speed of light is exponentially faster than the speed of sound. Our brains can correct the information though, or maybe we we simply don't interpret the visual fast enough to notice.

    But I guess the question you mean to ask is, "At what point can our brains notice a difference between the visual and the audio?" A big part of this of course depends on your distance from the stage. Let's assume that you are close enough that distance doesn't make a difference in your brain's judgement (maybe 5-20 feet or so).

    Well, it still wouldn't matter how many notes per second were played,because the sound will still reach your ears at the same rate. But I guess if you played at about 30 finger movements per second, you would start to notice a blur (the speed of movies is about 30 frames per second I believe). But this is still not an "out of sync" effect like you were looking for.

    For an out of sync effect to occur at a close distance, you would in fact have to play faster than the speed of sound. However, at this point we would not hear individual notes but more of a constant hum (and perhaps a sonic boom? hahahaha).

    The speed of sound being 1130 feet per second, and the average guitar fret being about an inch in size, you'd have to cross that fret 13,560 times in one second. That's a pretty fast trill indeed, and it'd just sound like a harmonic 2nd anyway.

  3. #3
    Registered User
    Join Date
    Dec 2007
    Posts
    485
    its called a delay pedal....

  4. #4
    Registered User ragasaraswati's Avatar
    Join Date
    Jan 2008
    Location
    Greece
    Posts
    293
    It's quite easy actually. Just shoot a bullet through a newspaper.

  5. #5
    chewing bubble gum Chim_Chim's Avatar
    Join Date
    Dec 2002
    Posts
    608
    it's a conspiracy....
    Some days I seem to do OK. Other days I feel like just shoving an M-80 right up my guitar's butt.

  6. #6
    Registered User
    Join Date
    Mar 2006
    Posts
    266
    or you could attach a guitar pick to your handheld electric mixer...?

  7. #7
    Registered User
    Join Date
    Feb 2008
    Posts
    8
    As a physics major, I couldn't resist this one. I'm going to further define the problem so we can find some numbers. Imagine that you are alternate picking two adjacent strings, say high E and B. Let's figure out the speed you would have to pick at so that when the sound from a downstroke on the E string reaches the listener, they will see you making an upstroke on the B string. We'll place the listener 5 meters away(about 15 feet). We can assume that the light reaches the listener instantly since light is so fast and this is a small distance(it would take light somewhere around 1/100000000 of a second to cross it)

    The speed of sound at sea level is about 340 m/s, so the sound will reach the listener roughly .0146 seconds later, so you better be making your next stroke at that point. This works out to 68.07 notes per second. Of course, there's no way or brains can distinguish things on such small time scales.


    As for what the listener hears, since you're hitting two different notes and humans can't hear below about 60 hz, I suspect they will just hear the two different notes as if they were being played continuously and simultaneously. If you were picking one note, I believe you'd hear another note based on how fast you were picking.

    Hope this is what you were looking for!

  8. #8
    Registered User
    Join Date
    Dec 2007
    Posts
    485
    Very interesting, and thank you for contributing Drummist. Always nice to have an educated view on these things.

    with my absolute ignorance on the subject. I could imagine your hands would also appear to be almost motionless and appearing in two places at once. Similar to a car wheel when driving on the highway. You know, how it appears to be moving extremely slow.

    I'm curious what you meant about the 60hz business though. Are you saying the pitch of the notes played will change when played at such a high speed?

    Also, since you studied physics. Are you aware of any studies that might have had anything to do with what we are talking about. Not so much with musical instruments. But the effect speed of sound produced can have on the sound itself??? if thats not just a dumb question

  9. #9
    Registered User
    Join Date
    Feb 2008
    Posts
    8
    I hope you were looking for a long winded reply, because you're about to get one. I guess I wasn't very clear about what I meant. I haven't studied sound specifically a whole lot, although I find it fascinating and am taking a course on it this semester. I'll take it from the top.

    Sound is just vibration, right? Different pitches are just different speeds of vibration. We all know that an 440 hz, or oscillations per second, is an A. One time I heard someone use a computer program to take a bunch of clicks and speed them up so there were 440 per second, and it just became a tone. When you hit an A string, it vibrates 440 times per second(and 880 times, and other amounts, these are the harmonics).

    Now, I'm honestly not exactly sure what happens you pick a vibrating string 60 times in a second. It seems like this would create a very complex wave on the string. If I had to guess, I would guess that you would hear the note of the string(and all the harmonics), as well as a tone with a pitch of 60 hz. That was what I was trying to say. Again, this is mostly guesswork on my part, I haven't really ever seen or heard it addressed by someone who knows what they're talking about. As a side note, it shouldn't matter how fast your hand is moving relative to the speed of sound, since your hand isn't making any noise.

    I think that answers your questions, at least as well as I can answer them. However, you reminded me of another relationship between speed and sound: the speed at which you're moving when you play also changes the pitch. The classic example is that if you listen to a train whistle before it passes you and after it passes you, they'll be at different pitches. This is called the Doppler effect, and is pretty simple but hard to explain over the internet. Look it up if you're interested.

    Not sure how much(if any) of this is new to everyone, but I hope it helps a bit. I'd be happy to answer any more questions to the best of my abiity. I've taken some good info from this site, and it's nice to be able to give back.

  10. #10
    Registered User
    Join Date
    Dec 2007
    Posts
    485
    Yea I'm aware of the harmonic series and Doppler effect.

    I wont argue the point because I honestly don't know enough to be sure. Regarding the vibrations of a string though.

    The speed at which you pick the string might not alter its sound so much as the amount of attacks on the string would.

    We know the string requires time to vibrate and actually achieve all those harmonic's via the vibration itself, for us to hear that tone... call it A 440.

    So if you were attacking/picking faster than the sound could be produced, wouldn't that leave us with nothing at all?? or maybe just the sound of the pick hitting the brass on the string? Which may well wind up sounding like a constant white noise.... and because of the speed this could well result in a sonic boom bursting everyones eardrums? Which would deafen us before we heard the result anyway. Hence it would sound like nothing at all.

    I don't know, just speculating. Maybe the answers lie in one of Einstiens un-tested theory's
    Last edited by JazzMick; 02-17-2008 at 03:14 PM.

  11. #11
    Registered User
    Join Date
    Sep 2007
    Location
    Venezuela
    Posts
    69
    Quote Originally Posted by Drummist222
    As a physics major, I couldn't resist this one. I'm going to further define the problem so we can find some numbers. Imagine that you are alternate picking two adjacent strings, say high E and B. Let's figure out the speed you would have to pick at so that when the sound from a downstroke on the E string reaches the listener, they will see you making an upstroke on the B string. We'll place the listener 5 meters away(about 15 feet). We can assume that the light reaches the listener instantly since light is so fast and this is a small distance(it would take light somewhere around 1/100000000 of a second to cross it)

    The speed of sound at sea level is about 340 m/s, so the sound will reach the listener roughly .0146 seconds later, so you better be making your next stroke at that point. This works out to 68.07 notes per second. Of course, there's no way or brains can distinguish things on such small time scales.


    As for what the listener hears, since you're hitting two different notes and humans can't hear below about 60 hz, I suspect they will just hear the two different notes as if they were being played continuously and simultaneously. If you were picking one note, I believe you'd hear another note based on how fast you were picking.

    Hope this is what you were looking for!
    I thought you could not SEE below 60 HZ.

    Correct me if I'm wrong, but I think monitors never go lower than 60hz because you would see flickering.

    I have mine set to 72 just for that.

  12. #12
    Registered User
    Join Date
    Feb 2008
    Posts
    8
    Quote Originally Posted by JazzMick
    Yea I'm aware of the harmonic series and Doppler effect.

    I wont argue the point because I honestly don't know enough to be sure. Regarding the vibrations of a string though.

    The speed at which you pick the string might not alter its sound so much as the amount of attacks on the string would.

    We know the string requires time to vibrate and actually achieve all those harmonic's via the vibration itself, for us to hear that tone... call it A 440.

    So if you were attacking/picking faster than the sound could be produced, wouldn't that leave us with nothing at all?? or maybe just the sound of the pick hitting the brass on the string? Which may well wind up sounding like a constant white noise.... and because of the speed this could well result in a sonic boom bursting everyones eardrums? Which would deafen us before we heard the result anyway. Hence it would sound like nothing at all.

    I don't know, just speculating. Maybe the answers lie in one of Einstiens un-tested theory's
    Einstein's theories deal with relativity and the cosmos. You clearly have no idea what you're talking about, and should probably just shut up.

    Just kidding, I'm pretty much just speculating too. What we have here is is called driven oscillation, and depending on the driving force, it can get pretty messy. I suppose I could try to do some math with it, and look at it as a damped, driven oscillator, but the answer we're looking for depends on how long it takes the string to start oscillating at its resonance frequency. Here's how I thought about it, though: you pick once, and the string starts vibrating at 440 Hz, then you pick again 1/60th of a second later, and then the string again starts oscillating at it's natural resonance frequency. So the pick imposes a new frequency on the string, but it also continues to vibrate at its own frequency. I figured our brains would interpret this as the 'original' note plus a new one, but I could be wrong. If you picked an A at 440 Hz, I'm quite sure the note would sound and be very loud(look up the Tacoma Narrows Bridge), and picking faster would presumably cut out the fundamental but still allow the overtones to sound.

    Incidentally, in class yesterday the professor said humans can hear as low as 20 Hz, so I guess I was wrong in my earlier post, sorry about that.

    As for seeing 60 Hz, I'm honestly not sure what you're talking about, as we're discussing frequencies of sound (which you obviously can't see no matter what, Magic School Bus notwithstanding), and I have little experience with monitors. Perhaps the monitors do not show anything under 60 Hz, or cannot play anything below 60 Hz? Or maybe this is an electrical oscillation? Alternating current has a frequency as well as a voltage(the socket is usually 50 or 60 Hz, depending on the country, I think). While light is a wave and has a frequency, I can't imagine a reason that you could adjust any light frequencies on a monitor. Sorry I couldn't be more helpful here.

    Thanks for indulging my long physics musings, ask if you want to hear more.

  13. #13
    Artistically Bankrupt
    Join Date
    Oct 2006
    Location
    U.S.A.
    Posts
    869
    To JazzMick's point, Drummist222, what if a string, vibrating at 440 Hz, were to be plucked 440 times in the next second? The matched oscillation would cancel it out, no? The string would never complete a peak to trough. If so, then any subpart of 440 plucks per second will of neccessity be a phased modulation, right? Would that original 440 Hz string vibration not therefore be different? Pursuant to that, would your original calculations not have to take into effect the dynamics of attack (the plucks causing the vibration)?
    "If a child learns which is jay and which is sparrow, he'll no longer see birds nor hear them sing."

  14. #14
    Registered User
    Join Date
    Feb 2008
    Posts
    8
    Quote Originally Posted by Blutwulf
    To JazzMick's point, Drummist222, what if a string, vibrating at 440 Hz, were to be plucked 440 times in the next second? The matched oscillation would cancel it out, no? The string would never complete a peak to trough. If so, then any subpart of 440 plucks per second will of neccessity be a phased modulation, right? Would that original 440 Hz string vibration not therefore be different? Pursuant to that, would your original calculations not have to take into effect the dynamics of attack (the plucks causing the vibration)?
    Really going to make me think about this one, eh? If you mean a pluck in the same direction every 1/440th of a second, it should actually amplify the note. See http://en.wikipedia.org/wiki/Mechanical_resonance . Imagine that you pluck it once, and the string then completes a cycle gets back to where it started 1/440th of a second later, when you pluck it again. Since your plucking is in harmony with the way the string is already moving, then it should amplify the sound. Note also that the amplitude of the peaks and troughs doesn't affect the pitch, just the frequency(and therefore the wavelength, wave number, etc.)

    If you were doing alternate picking, the second pick would be in the opposite direction of strings acceleration, but it seems to me that it would still increase the amplitude and keep the same frequency. Imagine this as a kid on a swingset, where you push out whenever the kid is at the top of a swing(this analogy is very useful for a lot of this stuff).

    I think, in view of this, the rest of your post is moot, but I'm not sure I followed your logic very well. As far as I can tell, my calculations should still be OK.

  15. #15
    SubterraneanHomesickAlien DuB's Avatar
    Join Date
    Jun 2007
    Location
    Oklahoma State University
    Posts
    131
    Or you can just stand very far away and watch the guitarist with binoculars, then he wouldn't have to play fast at all . Learned that one after I bought some really crappy concert tickets, lol.

Similar Threads

  1. Building speed and ending a fast run effectively
    By Darkman in forum Guitar Technique
    Replies: 1
    Last Post: 09-22-2007, 04:26 PM
  2. technique, speed etc.
    By asdf in forum Guitar Technique
    Replies: 105
    Last Post: 08-26-2007, 10:40 PM
  3. fast alternate picking easier with high-gain sound?
    By Santuzzo in forum Guitar Technique
    Replies: 10
    Last Post: 03-07-2007, 05:42 PM
  4. Picking speed on practice licks vs. real licks
    By rrhea in forum Guitar Technique
    Replies: 7
    Last Post: 11-27-2005, 05:32 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •