|
Post by antigua on Mar 21, 2017 12:19:05 GMT -5
In the first post, results for the variation of string magnetization along the string were shown. The results were obtained with an air core pickup coil, and thus they represent a spatial average over the sensitive range of the coil. The result were: "Three measurements are made by carefully plucking the string, one centered over the guitar pickup, and then slid along the strings by 3/32 and 3/16 inches. The measurements are converted to db referred to the centered measurement, and the measurements are 0 db, -3.1 db, and -18.4 db. " This post presents some results for the other half of the pickup problem: excite the the coil from different locations along where the string would be. This is done with a very small coil with a diameter about half of a pickup pole piece with three turns. The coil is driven with about 1 ampere at one KHz and the output the guitar is measured using an fft analyzer for each position. (The signal level excited by the small coil is not very big, and so it is a good idea to use a small frequency range and integrate for a few seconds.) The results for the same displacements from the center are 0 db, -1.8 db, and -4.7 db. Moving to the edge of the pickup gives -15.1 db. This is outside the coil. This result is quite a bit wider than the result for string magnetization. This is not surprising; although we expect the strongest concentration of flux through the pole piece, short pole pieces confine the flux imperfectly, and so the amplification of the incident field is not that high. This means that the pickup of flux coming into the coil but missing the pole is significant. So the overall result for both measurements added is 0 db, -4.9 db, and -27.1 db for centered, 2/32", and 3/16" from the center. The conclusion that the pole piece sets the sampling distance for this pickup is reinforced a bit although these are approximate measurements, and might vary some when better measurements are made. The next thing to measure is a humbucker. I might have missed it, but what is the height offset between the air coil and pickup, and the exciter coil and pickup, in the two tests?
|
|
|
Post by ms on Mar 21, 2017 17:07:12 GMT -5
In the first post, results for the variation of string magnetization along the string were shown. The results were obtained with an air core pickup coil, and thus they... I might have missed it, but what is the height offset between the air coil and pickup, and the exciter coil and pickup, in the two tests? Very close, about 3/32". My prejudice here was to find the minimum window. This would certainly increase at larger distances.
|
|
|
Post by antigua on Mar 21, 2017 17:50:21 GMT -5
I might have missed it, but what is the height offset between the air coil and pickup, and the exciter coil and pickup, in the two tests? Very close, about 3/32". My prejudice here was to find the minimum window. This would certainly increase at larger distances. That agrees with my testing. I didn't see a window that was much wider than the pole piece until 6mm, and that's a rather wide gap. Steel pole pieces appear to make the aperture remain more narrow, even with added distance. Since a humbucker has steel slugs and screws, I imagine that it's apertures will be narrow. There is a test I can perform tonight with that magnetometer that might suggest how much the flux angles inwards due to the assisted return path of the other coil's core, but I bet it's going to be very, very minimal.
|
|
|
Post by antigua on Mar 21, 2017 20:17:17 GMT -5
This doesn't say much about output, but it might be interesting anyway. Here are Gauss readings on a 5mm plane above a humbucker made by some US based company. 0mm is at the screw center.
|
|
|
Post by antigua on Mar 22, 2017 22:12:18 GMT -5
Here is the same thing for a Strat pickup. This one is a Lollar Blackface neck pickups with flat stagger AlNiCo 5's. It looks like the AlNico pole piece has a much tighter return path, flipping in polarity at only 5mm up and 15mm over from the center of the pole piece, where as the humbucker maintains it's pole/screw polarity past the ends of measurement, well in excess of 15mm
|
|
|
Post by ms on Mar 23, 2017 5:51:25 GMT -5
This doesn't say much about output, but it might be interesting anyway. Here are Gauss readings on a 5mm plane above a humbucker made by some US based company. 0mm is at the screw center. It looks as though the field from the slug side is very weak. Am I missing something?
|
|
frankfalbo
Meter Reader 1st Class
Posts: 74
Likes: 1
|
Post by frankfalbo on Mar 23, 2017 9:17:29 GMT -5
...on a 5mm plane above a humbucker. It looks as though the field from the slug side is very weak. Am I missing something? He's 5mm off the surface on a covered humbucker. So the slugs are probably 6-7mm away and not domed on top like the screws are. The difference at the peaks is only 60 vs 54 but then the slug overtakes the screw measurement toward the outside, accounting for the splay of the dome top and the elongated return path assuming they're normal length screw poles. If you're not married to the poles cut them flush with the baseplate and re-read.
|
|
|
Post by ms on Mar 23, 2017 9:38:07 GMT -5
It looks as though the field from the slug side is very weak. Am I missing something? He's 5mm off the surface on a covered humbucker. So the slugs are probably 6-7mm away and not domed on top like the screws are. The difference at the peaks is only 60 vs 54 but then the slug overtakes the screw measurement toward the outside, accounting for the splay of the dome top and the elongated return path assuming they're normal length screw poles. If you're not married to the poles cut them flush with the baseplate and re-read. That makes sense. Thanks.
|
|
|
Post by antigua on Mar 23, 2017 20:31:12 GMT -5
Here is a Strat ceramic/steel pickup. It appears that this pickup has a much wider return path, similar to the humbucker. It's interesting that the steel pole piece showed a tighter aperture in the practical amplitude test, even though it appears to cast flux wider across the string. It suggests that the steel poles are a more significant received of flux than provider of, where as AlNiCo is the opposite; provides much, receives little. Verrrry interesting.
|
|
frankfalbo
Meter Reader 1st Class
Posts: 74
Likes: 1
|
Post by frankfalbo on Mar 24, 2017 0:35:35 GMT -5
In other forums and on podcasts, I've used the phrase "neodymium is a magnet that doesn't like to be disturbed." Now, without everyone keyboard warrior-ing me for using Sesame Street terms, do you have the ability to repeat the amplitude tests with a ceramic bar underneath the steel pole? It doesn't have to be the two opposing bars flanking the poles like some cheap singles, just one across the middle.
|
|
|
Post by antigua on Mar 24, 2017 1:36:01 GMT -5
In other forums and on podcasts, I've used the phrase "neodymium is a magnet that doesn't like to be disturbed." Now, without everyone keyboard warrior-ing me for using Sesame Street terms, do you have the ability to repeat the amplitude tests with a ceramic bar underneath the steel pole? It doesn't have to be the two opposing bars flanking the poles like some cheap singles, just one across the middle. I would have used ceramic from the get go, but there's a practical problem: the test has only one pole piece, if I used this same ready-to-go pickup I have six slugs in place. They're essentially impossible to remove with the single magnet in the way. The magnet is hard to remove without shattering, because it's glued on. So it's also hard to take the magnet off in order to transplant it to the test pickup. There are some solutions, such as place the whole pickup, magnet and all, over the test pickup and use the other side of the pickup, or source another ceramic magnet, from my refrigerator perhaps. Or I can just use the pickup with all six pole pieces and accept that it's qualitatively different from the other tests. But those are impure test setups since the bring extra variables into it. The reason I'm not quick to bend over backwards for this is because neodymium and ceramic share important qualities, that being that both have (virtually) no permeability or conductivity. Speaking of "disturbed", as these are non-metallic, you could say they're exceptionally indifferent to what happens around them. AFAIK, their only big difference, that we would care about, is with respect to residual flux density, or strength. In addition to that, it seems that the bigger determinant in the aperture owes to the steel slug. Between the one tab and five tabs, the output voltage changed, but the dBm/displacement gradient didn't really change. There have been claims made about neo "sounding" different somehow. If that's at all true, I think at the very least we'd need FFT analysis, as aperture width, or dB by displacement, is just a single data point that doesn't directly map to a particular sound - at least not at this moment. If time permits, I'll just try placing the whole pickup over the test pickup. That's the cleanest option.
|
|
|
Post by ms on Mar 24, 2017 7:44:34 GMT -5
In other forums and on podcasts, I've used the phrase "neodymium is a magnet that doesn't like to be disturbed." Now, without everyone keyboard warrior-ing me for using Sesame Street terms, do you have the ability to repeat the amplitude tests with a ceramic bar underneath the steel pole? It doesn't have to be the two opposing bars flanking the poles like some cheap singles, just one across the middle. ------------------------------------------------------------------------------------ Frank, I think you are saying neo cannot easily be disturbed, not that the results of doing so are bad! It is just a mass of magnetic dipole magnets, nearly as many as the material can provide, all lined up in the same direction. It's response to an applied field is a few percent greater than a vacuum. It acts like an air gap that provides a magnetic driving force. Contrast that with alnico, which was a kind of miracle material when discovered, but is far from simple to use (and of course this complexity can be used to great advantage in some applications).
But ceramic materials are complicated. Since hard ferries (that is, permanent magnets) have high coercivity, it is hard to believe they also have high permeability, but that is exactly what many sources on the web say. Maybe they mean high compared to neo, but surely they are low compared to soft ferries, which are not permanent magnets. As for actual measurements, look here: www2.warwick.ac.uk/fac/sci/wmg/about/people/profiles/kkm/magnetic_and_structural_properties_of_mtype_barium_hexaferrite.pdf. In the audio range, it appears that materials commonly used for ferrite magnets have a permeability of about 1.3, based on the low frequency data in plots in this paper. I would call that low permeability for our purposes since it is low compared to alnico and much lower than steel. So I think that ceramic and neo share the property of not being easily disturbed, but neo much more so.
|
|
frankfalbo
Meter Reader 1st Class
Posts: 74
Likes: 1
|
Post by frankfalbo on Mar 24, 2017 11:27:25 GMT -5
If time permits, I'll just try placing the whole pickup over the test pickup. That's the cleanest option. nah don't bother that will change the return path yet again if there are poles below the ceramic. I was trying to show a correlation between the base magnet material and the volume drop off you see at farther distances that's all.
|
|
|
Post by reTrEaD on Mar 24, 2017 11:29:56 GMT -5
ms, I noticed several of the guys who are posting here after using other message boards seem to have difficulty with quotes.
If you're using the "Preview" function before you add something after the quote, you won't be able to put new text outside the quote box.
Try switching to "BBCode" mode and adding something outside the quote. Then if you switch back to "Preview" because you're more comfortable with the wysiwyg style of post creation, you will be able to type outside the box.
|
|
frankfalbo
Meter Reader 1st Class
Posts: 74
Likes: 1
|
Post by frankfalbo on Mar 24, 2017 11:42:13 GMT -5
I think you are saying neo cannot easily be disturbed, not that the results of doing so are bad! I don't want to derail the thread, sorry. But since you're rephrasing me I'll clarify that yes I have said it within the context of my personal feelings in pickup designs, at least for electric guitar. I don't like it's use in electric guitar pickups. Theres an attack and early envelope I don't love. It's been proven effective in acoustic soundhole pickups (usually set much further from the strings and with non-magnetic wrap material) and it can be effective in bass with the greater string mass. Another exception is that Tom Anderson uses it on some pickups, but it's that soft, flexible neo strip magnet material that does not exhibit the same qualities.
|
|
|
Post by antigua on Mar 24, 2017 12:47:57 GMT -5
I don't think this aperture examination will yield much in the way of what magnets are "effective" or otherwise, that would require FFT analysis (that is informed by these test results) in order to measure amplitude differences with respect to frequency, as well as transient analysis to see if there is any difference in attack and decay, but the problem there is the transient should be a moving guitar string, not an applied magnetic field, which is a hard-to-very-hard test to design, setup and carry out. One reason I haven't gone there too much yet is for the reason stratotarts mentioned some time ago, there is no explanation as to why the attack and decay should differ when the magnetic field is stronger, aside from inter-modulation effects. I think most people agree there is a difference we hear, but we don't even have much of a theory as to why there should be a difference. Without even a theory to start from, there's no guide map. Suppose we see a difference in FFT, what does it mean? Where do you go from there? Manfred Zollner had some findings in regard to string pull and harmonic inter-modulation guitarnuts2.proboards.com/thread/7791/manfred-zollners-physik-elektrogitarre-observations Does that explain the difference? I don't know. We need more of a foundation to start from as to what the heard difference actually is, before trying to explain it.
|
|
|
Post by ms on Mar 24, 2017 13:21:02 GMT -5
I think you are saying neo cannot easily be disturbed, not that the results of doing so are bad! I don't want to derail the thread, sorry. But since you're rephrasing me I'll clarify that yes I have said it within the context of my personal feelings in pickup designs, at least for electric guitar. I don't like it's use in electric guitar pickups. Theres an attack and early envelope I don't love. It's been proven effective in acoustic soundhole pickups (usually set much further from the strings and with non-magnetic wrap material) and it can be effective in bass with the greater string mass. Another exception is that Tom Anderson uses it on some pickups, but it's that soft, flexible neo strip magnet material that does not exhibit the same qualities. No problem, I think we have lost precise focus in this discussion. As for neo, personal preferences are fine, but facts are facts. Neo is a very neutral material, and makes a very strong field. I am surprised to see it used as pole pieces in some designs. Then you have an air core coil and too strong a field. You want to use a permeable material as a pole piece to amplify the flux from the vibrating string, and then use just enough magnet to get the field you want. For example, if you use a ceramic pole piece, and want to put the magnet on top, a neo magnet 3/16" in diameter and 1/32" thick gives field that is too strong if you want to put the pickup close to the string. 1/16" dia., 1/32"thick gives more flexibility in height adjustment. From my pov, a material that gives a strong field and has very low permeability is the best to use because you have the most flexibility in how you can use it with other materials to get the design that you want.
|
|
|
Post by ms on Mar 24, 2017 13:42:01 GMT -5
One reason I haven't gone there too much yet is for the reason stratotarts mentioned some time ago, there is no explanation as to why the attack and decay should differ when the magnetic field is stronger, aside from inter-modulation effects. But there is a possible reason: the magnetic field affects the vibration of the string. You do not just have to believe your ears, but you can use your eyes as well. Put a string in a very strong field and yo can see it move differently from no field. Why? Well that is a complicated physics problem. But you can see why it might be so. The magnetic field varies with distance from the pickup. This means that the restoring force generated when the string moves off rest position is complicated. String vibration, if started in on plane, rotates. If the properties of the vibration differ across the top of the pickup and towards it, then you have a very complicated situation when it tries to rotate because the field does not vary as much across the top of the pickup as towards it. This would affect the attack most because this is when the amplitude of motion is greatest and so the encountered changes in the field are greatest. It could affect the sound of the decay, because the rate of decay is a different function of the amplitude than when there is no field. Speculation, yes, but there is a reason that can in principle be investigated.
|
|
|
Post by antigua on Mar 24, 2017 14:07:54 GMT -5
One reason I haven't gone there too much yet is for the reason stratotarts mentioned some time ago, there is no explanation as to why the attack and decay should differ when the magnetic field is stronger, aside from inter-modulation effects. But there is a possible reason: the magnetic field affects the vibration of the string. You do not just have to believe your ears, but you can use your eyes as well. Put a string in a very strong field and yo can see it move differently from no field. Why? Well that is a complicated physics problem. But you can see why it might be so. The magnetic field varies with distance from the pickup. This means that the restoring force generated when the string moves off rest position is complicated. String vibration, if started in on plane, rotates. If the properties of the vibration differ across the top of the pickup and towards it, then you have a very complicated situation when it tries to rotate because the field does not vary as much across the top of the pickup as towards it. This would affect the attack most because this is when the amplitude of motion is greatest and so the encountered changes in the field are greatest. It could affect the sound of the decay, because the rate of decay is a different function of the amplitude than when there is no field. Speculation, yes, but there is a reason that can in principle be investigated. I think you're describing the inter-modulation I mentioned, where you apply magnetic damping to one half of the string, but not the other, causing a "warbling". If a pickup is far enough away from the strings, this effect is not problematic, but what you would be saying otherwise is that even when this effect is not "problematic", it is still coloring the sound, just not to an extent that is deemed to sound bad. But the point being, it's different degrees of the same effect. One reason I don't think that is true, is that if it were, all three pickups in a Strat would contribute this this particular "close proximity" tone, but it seems to me that each pikcup's height is solely responsible for it's own tone, in that respect. In other words, a bridge humbucker sounds more "lively" when it is close to the strings. Putting the neck pickup close to the strings instead does not also cause the lowered bridge humbucker to sound more "lively". The effect seems to relate to the selected pickup AND string interaction, not in how all of the pickups, selected or not, effect the string cumulatively. Another thing that happens, is if there is an anti node over a pole piece, that particular harmonic will be diminished, which is what I think was seen with Zollner's experiment, but the question might become how knocking down some harmonics would contribute to that more "lively" sound. I think we need more smaller experiments to build up a body of data. dB by offset is just the start.
|
|
frankfalbo
Meter Reader 1st Class
Posts: 74
Likes: 1
|
Post by frankfalbo on Mar 24, 2017 14:29:58 GMT -5
In other words, a bridge humbucker sounds more "lively" when it is close to the strings. Putting the neck pickup close to the strings instead does not also cause the lowered bridge humbucker to sound more "lively". The effect seems to relate to the selected pickup AND string interact, not in how all of the pickups, selected or not, effect the string magnetically. It's because of the pattern increases as you get further away from the bridge.
|
|
|
Post by antigua on Mar 24, 2017 14:59:43 GMT -5
In other words, a bridge humbucker sounds more "lively" when it is close to the strings. Putting the neck pickup close to the strings instead does not also cause the lowered bridge humbucker to sound more "lively". The effect seems to relate to the selected pickup AND string interact, not in how all of the pickups, selected or not, effect the string magnetically. It's because of the pattern increases as you get further away from the bridge. You say these things with a lot of certainty, but a lot more supporting evidence is required before we can claim to have actual certainty. Not only evidence, but also theories. "Pattern" sounds like a feature of a theory that have not heard articulated.
|
|
frankfalbo
Meter Reader 1st Class
Posts: 74
Likes: 1
|
Post by frankfalbo on Mar 24, 2017 18:05:44 GMT -5
It's because of the pattern increases as you get further away from the bridge. You say these things with a lot of certainty, but a lot more supporting evidence is required before we can claim to have actual certainty. Not only evidence, but also theories. "Pattern" sounds like a feature of a theory that have not heard articulated. Maybe we're not saying the same thing then, or you're not hearing me right. I'll try to isolate each thing I'm saying: When a pole piece gets too close to a string it can cause a warbly sound, that is pretty universally disliked. Some refer to this as Strat-itis. All things equal, this happens more on the neck pickup than the middle, and more on the middle than the bridge. The reason is because the string vibrates in a larger pattern the further from the bridge you get. That's all I'm saying. It's more vulnerable.
|
|
|
Post by ms on Mar 24, 2017 18:18:34 GMT -5
I think you're describing the inter-modulation I mentioned, where you apply magnetic damping to one half of the string, but not the other, causing a "warbling". OK, we are talking about the same thing, but I do not see what damping on one half of the string has to do with it. Hold a neo button near a string and compare the motion that you see with what you see when it is not there. There is an effect you can see right there where the magnet is. The closer you get, the faster the beating, and the more you can see the string deviating from normal vibration. Yes, damping is involved to the extent that the higher harmonics are knocked way down when the effect is strong, but I think this effect has to do with changes in vibration in the direction of the magnet while the direction perpendicular is changed much less.
|
|
|
Post by antigua on Mar 25, 2017 2:46:34 GMT -5
I think you're describing the inter-modulation I mentioned, where you apply magnetic damping to one half of the string, but not the other, causing a "warbling". OK, we are talking about the same thing, but I do not see what damping on one half of the string has to do with it. Hold a neo button near a string and compare the motion that you see with what you see when it is not there. There is an effect you can see right there where the magnet is. The closer you get, the faster the beating, and the more you can see the string deviating from normal vibration. Yes, damping is involved to the extent that the higher harmonics are knocked way down when the effect is strong, but I think this effect has to do with changes in vibration in the direction of the magnet while the direction perpendicular is changed much less. I'm thinking the test I have to do next is sample wave forms at various heights, with a pickup that has an extremely weak magnet, so that proximity effects can be isolated from "observer interference" effects, caused by a strong pole piece that interferes with the vibration of the string, the closer it gets to the string. A steel pole piece with no magnet backing it actually has a high enough Br to produce a sound, but is weak enough to not pull on the string to any meaningful extent.
|
|
|
Post by ms on Mar 25, 2017 6:39:15 GMT -5
OK, we are talking about the same thing, but I do not see what damping on one half of the string has to do with it. Hold a neo button near a string and compare the motion that you see with what you see when it is not there. There is an effect you can see right there where the magnet is. The closer you get, the faster the beating, and the more you can see the string deviating from normal vibration. Yes, damping is involved to the extent that the higher harmonics are knocked way down when the effect is strong, but I think this effect has to do with changes in vibration in the direction of the magnet while the direction perpendicular is changed much less. I'm thinking the test I have to do next is sample wave forms at various heights, with a pickup that has an extremely weak magnet, so that proximity effects can be isolated from "observer interference" effects, caused by a strong pole piece that interferes with the vibration of the string, the closer it gets to the string. A steel pole piece with no magnet backing it actually has a high enough Br to produce a sound, but is weak enough to not pull on the string to any meaningful extent. And if that is too weak, you can use very small news on the bottom of the pole, the end away from the string.
|
|
|
Post by stratotarts on Mar 25, 2017 7:30:28 GMT -5
The magnet can't damp the vibration, exactly. The amount of energy gained as the string approaches the magnet is equal to the amount of energy lost as it moves away. But the harmonics are waves that are controlled by the location of fixed points in the string because they act as reflectors - normally the endpoints. As the force resulting from the magnetic field approaches the force due to the displacement of the strings elasticity, the magnet becomes a fulcrum that reflects some of the displacement energy back into the string. This causes the normal harmonics to be translated to new harmonics that are related to the distances between the magnet and the fixed end points. Since the fulcrum is "soft", they don't maintain themselves, but rely on continuing excitation from the string.
Theory based on general physics - of course it's up for debate and testing. Actually a good way would be to look for the translated harmonics in a spectral plot. I guess this is a different topic though, perhaps deserves another thread if it needs further explication.
|
|
|
Post by ms on Mar 25, 2017 12:53:28 GMT -5
The magnet can't damp the vibration, exactly. The amount of energy gained as the string approaches the magnet is equal to the amount of energy lost as it moves away. But the harmonics are waves that are controlled by the location of fixed points in the string because they act as reflectors - normally the endpoints. As the force resulting from the magnetic field approaches the force due to the displacement of the strings elasticity, the magnet becomes a fulcrum that reflects some of the displacement energy back into the string. This causes the normal harmonics to be translated to new harmonics that are related to the distances between the magnet and the fixed end points. Since the fulcrum is "soft", they don't maintain themselves, but rely on continuing excitation from the string. Theory based on general physics - of course it's up for debate and testing. Actually a good way would be to look for the translated harmonics in a spectral plot. I guess this is a different topic though, perhaps deserves another thread if it needs further explication. I suspect that the mechanism that you described has some subtle features as well. For example, as the string moves in the direction of the axis of the pole (up and down, we sometimes say), the magnetic force varies. I think this interruption in the properties of the string disrupts the buildup off energy in any higher harmonics. That is, there is no set of harmonics in which energy can build up from multiple reflections, and so much of the energy that would go into string motion at these harmonics is just dissipated in string bending.
|
|
|
Post by antigua on Mar 25, 2017 14:12:56 GMT -5
One adjective uised to describe the close proximity sound is the "wow" or "wah" sound as the string rings out. One possibility that seems plausible to me is that the "wow" sound is caused by the magnet impacting particular harmonics (either suprressing, or overemphasizing them) while the string is moving close to the pickup, and then this effect decreases as the area of string movement decreases and fails to come as close to the pickup.
I'll try some practical experiments with a neo near the string as suggested, but again, I feel that if magnetic pull were a major cause, then you would hear the overall character of the guitar's tone change, even acoustically, as the pickups are raised and lowered. I do not believe that happens, though.
|
|
|
Post by ms on Mar 25, 2017 14:52:43 GMT -5
One adjective uised to describe the close proximity sound is the "wow" or "wah" sound as the string rings out. One possibility that seems plausible to me is that the "wow" sound is caused by the magnet impacting particular harmonics (either suprressing, or overemphasizing them) while the string is moving close to the pickup, and then this effect decreases as the area of string movement decreases and fails to come as close to the pickup. I'll try some practical experiments with a neo near the string as suggested, but again, I feel that if magnetic pull were a major cause, then you would hear the overall character of the guitar's tone change, even acoustically, as the pickups are raised and lowered. I do not believe that happens, though. The wowing is a beat, caused by two frequencies separated by the wow frequency. If a very strong magnet destroys higher harmonics, as it clearly does, what does it do to lower harmonics and the fundamental? Since the interrupted region is a fraction of a wavelength, it does not destroy theses lower harmonics, but rather shifts the frequency. The beat is then with the much less shifted frequency in the other plane of vibration, with some odd effects explained by vibrations attempting to rotate as they do in an unperturbed string.
|
|
frankfalbo
Meter Reader 1st Class
Posts: 74
Likes: 1
|
Post by frankfalbo on Mar 25, 2017 17:34:57 GMT -5
Some other observable phenomena to use as a cross reference are the way a string can produce an out of tune or double (chorused) pitch under this focused field too close to the string. This is similar to what can happen when someone says they have a "bad string" which is a string with an inconsistency (heavy spot) within the plain or core, or a wrap that's bulging or compressed in one area and not in the other.
The other is that in a guitar with low action, there can be a point where raising the neck single coil close enough to the strings will cause more fret buzz to occur. This is one way (as well as cameras) we can see a measurable pull-down.
All this to say that if establishing a string window parameter there will be a point where proximity has a drawback that exceeds the benefit. Like you might discover that the "best" place for one attribute is not good for another.
|
|