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Thread: One problem with the 408's and NF pickups

  1. #21
    The guitar will still make a harmonic, it just won't be "picked-up" by a pickup that is directly under a node of that harmonic. The string doesnt move there and if a string doesnt move in the magnetic field of a pickup, the pickup doesn't pick it up. The harmonic is still hapenning, it just isnt gonna be picked up by a pickup.

  2. #22
    A♥ hoards guitars A♥ rugerpc's Avatar
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    Quote Originally Posted by leeasam View Post
    hmm. interesting. if you are talking touching the string lightly right over fret for harmonics like doing the 12th fret deal for intonation ? does the guitar do it fine unplugged?? those kind of harmonics are not dependant on gain etc as even an acoustic guitar can do them. I know on my P22 I can get harmonics all over unplugged. never tried it on neck PU plugged in though. Maybe I am not wrapping my mind around this properly but if it harmonics unplugged it should plugged in right? the pick up is basically a form of a mic. Pick up hight make a difference? hmm not sure but if it harmonics unplugged for some reason seems to me should still even plugged in.
    The pickup is NOT a mic. Signal generation is by electrical induction in the coil caused by the string's vibration (read: motion) in the coil's magnetic field. "Sound" has NOTHING to do with how magnetic pickups work - they are completely 'deaf'. (At least the correctly potted ones are - but that's a different discussion ).

    Consider that sound requires a medium through which to travel like air or water or rock, etc. In a vacuum, you could hit the strings on a guitar (acoustic or electric) and it would be dead silent. An electric guitar, though, WOULD produce a signal via the interaction of the moving string and the pups. Yes, even in a vacuum.

    Read post #5 above...
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  3. #23
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    Doc - I'll try to make a vid for you...

    In the mean time, I'll try a verbal explanation. The harmonics we are talking about are also called 'natural harmonics'. They are produced by lightly touching a string at precise points to stop it from vibrating at that point, producing a 'node.'

    Lightly touching a string at the 12th fret while picking or striking it will produce a node over the 12th fret effectively dividing the string into TWO vibrating segments, not just one. The harmonic note produced will be an octave above the note of the unftetted string.

    Lightly touching a string at the 5th fret while picking or striking it will produce a node over the 5th fret (plus a node above the 12th fret and another over the neck pickup) effectively dividing the string into FOUR vibrating segments, not just one. The harmonic note produced will be TWO octaves above the note of the unftetted string.

    Lightly touching a string at the 7th fret while picking or striking it will produce a node over the 7th fret (plus a node above the 19th fret) effectively dividing the string into THREE vibrating segments, not just one. The harmonic note produced will be one octave above the note of the string if it were fretted at 7.

    Knowing where the other nodes are makes it possible to produce the 5th fret harmonic and the 7th fret harmonic in other places... You can get the same harmonic as over the 5th fret by lightly touching the string just over the neck pickup - move back and forth until you find it. You can get the same harmonic as the one over the 7th fret by lightly touching the string over the 19th fret.
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  4. #24
    Senior Member clcwarlock's Avatar
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    Quote Originally Posted by rugerpc View Post
    The pickup is NOT a mic. Signal generation is by electrical induction in the coil caused by the string's vibration (read: motion) in the coil's magnetic field. "Sound" has NOTHING to do with how magnetic pickups work - they are completely 'deaf'. (At least the correctly potted ones are - but that's a different discussion ).

    Consider that sound requires a medium through which to travel like air or water or rock, etc. In a vacuum, you could hit the strings on a guitar (acoustic or electric) and it would be dead silent. An electric guitar, though, WOULD produce a signal via the interaction of the moving string and the pups. Yes, even in a vacuum.

    Read post #5 above...
    Not trying to derail the topic but, I agree with this and always wondered why people would mount pickups directly to the guiatar. I am guessing it has to do with non potted pickups that pickup microphonics a little.
    Last edited by clcwarlock; 05-02-2013 at 10:34 AM.

  5. #25
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    Quote Originally Posted by docbennett View Post
    Yup....that was my "basic understanding" but I have a lot of difficulty understanding how this is actually used during a solo. I am familiar with "pinch harmonics" but I have never really gotten a good handle on "natural harmonics" and would really appreciate a video that actually provides a demonstration of how they are used in a song.
    A great example of the problematic harmonic in question is in Journey's song Stone in Love. When the second section of the tune starts (basically the lead-in to the outro solo), there's a build up with keys and guitars that ends with Neal Schon hitting a 5th fret harmonic on the open G string and hitting the whammy bar.

    You can hear it around 2:54 in this video: http://www.youtube.com/watch?v=2uA1ksmnwPc
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  6. #26
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    Quote Originally Posted by docbennett View Post
    Yup....that was my "basic understanding" but I have a lot of difficulty understanding how this is actually used during a solo. I am familiar with "pinch harmonics" but I have never really gotten a good handle on "natural harmonics" and would really appreciate a video that actually provides a demonstration of how they are used in a song.
    I may have a vid for you next week, Doc. Maybe a 2 fer - one on the harmonics and one where harmonics lend themselves in a little Metallica number....

    edit: Here is a master of natural harmonics: Tony McManus and "Desert Dance" watch the harmonics begin at around 1:38.



    You can get all those harmonics on an electric, but your should probably use the bridge pup....
    Last edited by rugerpc; 05-02-2013 at 11:06 AM.
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  7. #27
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    Harmonics are integer multiples of a fundamental frequency. We move up one octave every time we double frequency; therefore, harmonics that are powers of two (2nd, 4th, 8th, 16th, 32nd) are octaves. A natural harmonic is the 2nd harmonic, which means that its frequency is two times that of the fundamental note's frequency (i.e., the harmonic on the 12th fret is equal in frequency to the fretted note at the 24th fret). It also means that the frequency's wavelength is one-half of the fundamental note's wavelength. If rugerpc's hypothesis is correct, the focal point of the neck pickup's magnetic field should lie halfway between the 5th fret and the nut.

  8. #28
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    Quote Originally Posted by Em7 View Post
    Harmonics are integer multiples of a fundamental frequency. We move up one octave every time we double frequency; therefore, harmonics that are powers of two (2nd, 4th, 8th, 16th, 32nd) are octaves. A natural harmonic is the 2nd harmonic, which means that its frequency is two times that of the fundamental note's frequency (i.e., the harmonic on the 12th fret is equal in frequency to the fretted note at the 24th fret). It also means that the frequency's wavelength is one-half of the fundamental note's wavelength.
    yes.


    Quote Originally Posted by Em7 View Post
    If rugerpc's hypothesis is correct, the focal point of the neck pickup's magnetic field should lie halfway between the 5th fret and the nut.
    I'm not sure pickups have 'focal points'. Their magnetic fields have 'poles' and the field surrounds the pickups themselves. The field moves in relation the pickup because the magnets (and the windings) are stationary. To move the field, you have to move the pup.

    As for the natural harmonic at the 5th fret, it has nodes at the nut, above the 5th fret, above the 12th fret, at a point over the neck pickup equal to 1/4 the string length and at the bridge. That is, 5 nodes and 4 equal-length vibrating segments.

    That puts the maximum vibrational amplitude for each segment halfway between each node. So if you could place a pup in any of these halfway points, whether on the neck between nodes or in the spot halfway between the node over the neck pup and the bridge, yes, that is where you would get maximum signal strength for that harmonic.
    Last edited by rugerpc; 05-02-2013 at 12:10 PM.
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  9. #29
    deus ex machina
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    There are actually two magnetic fields at work in a pickup. The B-field is produced by the magnetic flux of the magnets. The H-field is produced by the strings vibrating within the B field (i.e., the current that is induced into the coil creates a magnetic field). Aren't magnetic transducers fun?
    Last edited by Em7; 05-02-2013 at 01:11 PM.

  10. #30
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    Quote Originally Posted by rugerpc View Post
    As for the natural harmonic at the 5th fret, it has nodes at the nut, above the 5th fret, above the 12th fret, at a point over the neck pickup equal to 1/4 the string length and at the bridge. That is, 5 nodes and 4 equal-length vibrating segments.
    Actually, the nodes only appear at the vibrational frequency's zero crossings. A string vibrates in an elliptical pattern that is only one half the fundamental frequency's wave length in length (one half of the ellipse is the positive excursion and the other half is the negative excursion of the period), which is why a node appears at the nut and the bridge when a string is played open. After a note is fretted, the nut no longer becomes part of the equation unless it is a multiple of the fundamental note. The anti-nodes (signal peaks) appear at 90 and 270 degrees with respect to the signal period. The nodes appear at 0, 180, and 360 degrees.




  11. #31
    Member boxstop7's Avatar
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    Quote Originally Posted by Em7 View Post
    Actually, the nodes only appear at the vibrational frequency's zero crossings. A string vibrates in an elliptical pattern that is only one half the fundamental frequency's wave length in length (one half of the ellipse is the positive excursion and the other half is the negative excursion of the period), which is why a node appears at the nut and the bridge when a string is played open. After a note is fretted, the nut no longer becomes part of the equation unless it is a multiple of the fundamental note. The anti-nodes (signal peaks) appear at 90 and 270 degrees with respect to the signal period. The nodes appear at 0, 180, and 360 degrees.



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  12. #32
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    Tried the 5th fret harmonic on the G string of my NF3 ,clean and with gain, bit weak but it's there. The action is a bit on the high side though.

  13. #33
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    Quote Originally Posted by Em7 View Post
    Actually, the nodes only appear at the vibrational frequency's zero crossings. A string vibrates in an elliptical pattern that is only one half the fundamental frequency's wave length in length (one half of the ellipse is the positive excursion and the other half is the negative excursion of the period), which is why a node appears at the nut and the bridge when a string is played open. After a note is fretted, the nut no longer becomes part of the equation unless it is a multiple of the fundamental note. The anti-nodes (signal peaks) appear at 90 and 270 degrees with respect to the signal period. The nodes appear at 0, 180, and 360 degrees.



    Thanks for the illustration! It works for the 5th fret natural harmonic.
    Consider the leftmost node (red dot) to be the nut (node 1).
    Consider the second from left to be the node you induce by lightly touching the string over the 5th fret (node 2).
    Consider the middle red dot to be the node induced over the 12th fret (node 3).
    Consider the next to far right dot to be the node induced over the neck pickup (node 4) and the reason for that pup's low signal strength.
    Consider the rightmost red dot to be the bridge (node 5).

    In post 5 above, I talked briefly about how the wave form on either side of the middle nodes is opposite at any one time:
    "...the string is vibrating in the exact opposite wave on dither side of a node. Any signal produced by these small amplitude movements would be very soft to start with and might even get cancelled out due to the opposite direction vibrations." (spelling corrections: dither = either and cancelled = canceled)
    Last edited by rugerpc; 05-02-2013 at 03:14 PM.
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  14. #34
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    Quote Originally Posted by guitarsong View Post
    Tried the 5th fret harmonic on the G string of my NF3 ,clean and with gain, bit weak but it's there. The action is a bit on the high side though.
    It should be louder on the bridge pup when struck at the same force....
    Thbbbbbt...
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  15. #35
    actually, there's not a thing i can find wrong at all with the narrowfields. i think their the BEST pickup i've ever played in my life. my love for these have no end. (but i know i'm in the VERY small minority in this opinion)

  16. #36
    deus ex machina
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    Okay, I did some measuring and experimenting when I got home from work this evening. The dominant natural harmonic at the 5th fret appears to be the 4th harmonic of the string when played open (two octaves up). This outcome makes sense because the length of string between the nut and the 5th fret is in play during a natural harmonic, and the distance between the 5th fret and the nut is one-fourth the total length of the string; therefore, the standing wave produced is four times shorter than the wave that is produced when the string is played open. As rugerpc mentioned above, the harmonic standing wave crosses the zero axis at the nut, fifth fret (one-fourth the total string length from the nut), 12th fret (one-half the total string length), 24th fret (one-fourth the total string length from the bridge), and the bridge. I haven't measured my only other 22-fret electric guitar, but the neck single coil on my 22-fret Ibanez S540 is dead on the 24th fret zero crossing.

    On a related topic, has anyone ever wondered how harmonic tuning works? When we combine two different frequencies, we get sum and difference frequencies. The sum and difference frequencies are heterodynes, which are heard as beats. The beats disappear as the two original
    frequencies converge. As mentioned above, the natural harmonic at the 5th fret is two octaves (24 half steps) up from the open string note. The natural harmonic on the 7th fret is an octave and a perfect fifth (12 + 7 = 19 half steps) above the open string. All of the strings on a guitar tuned a perfect 4th (5 half steps) apart in pitch (except for G to B, which is a major third); therefore, the natural harmonic on the 7th fret of the higher pitched string is 19 + 5 = 24 half steps above the lower pitched string, which is the same note as the natural harmonic on the 5th fret of the lower pitched string. The 12th fret harmonic on the G string and fretted 8th-fret note on the B string are both an octave above the open G string.

    Heterodyning is used in radio and television reception to remove audio and video signals from their carrier frequencies. However, that subject way outside the scope of this discussion.

  17. #37
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    Quote Originally Posted by helmi View Post
    actually, there's not a thing i can find wrong at all with the narrowfields. i think their the BEST pickup i've ever played in my life. my love for these have no end. (but i know i'm in the VERY small minority in this opinion)
    To be clear, I'm a huge NF and 408 fan. As soon as my hardtail SAS comes back from the PTC, I'll have 4 guitars with NFs and 3 guitars with 408s. But nothing is perfect.
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  18. #38
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    Quote Originally Posted by hippietim View Post
    To be clear, I'm a huge NF and 408 fan. As soon as my hardtail SAS comes back from the PTC, I'll have 4 guitars with NFs and 3 guitars with 408s. But nothing is perfect.
    If you find the time, please measure the actual length of each string between the nut and the bridge and the distance from the bridge saddles to the center of the neck pickup on each guitar. Being 22-fret guitars, I suspect that the distance from the bridge saddles to the center of the neck pickup will be 1/4th of the string length; however, it would be interesting to see if they are slightly off axis. Here's one place where the off-axis 24-fret guitar neck humbucker is useful.

  19. #39
    CLIMBING VINTAGE PRS MT.
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    Tried it last night with my Brent Mason. Humbucker mode no problem single coil problem.

  20. #40
    Quote Originally Posted by hippietim View Post
    To be clear, I'm a huge NF and 408 fan. As soon as my hardtail SAS comes back from the PTC, I'll have 4 guitars with NFs and 3 guitars with 408s. But nothing is perfect.
    what 4 guitars with nf's do you have? man, that sounds like heaven, especially a hardtail sas.

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