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Post by sumitagarwal on Mar 14, 2024 8:21:43 GMT -5
Another factor I forgot about, if we're talking about higher frequency harmonics, they don't last long after the transient. So if you say the comb filtering only effects higher harmonics, then it will be limited to a "pick attack" modification of the sound. I think low harmonics are definitely filtered as the math describes, because you can fake the sound of "notch positions" with a graphic EQ by copying the comb filter, but not only that, if not for the comb filtering, the notch positions would sound more like a true blend of constituent pickup signals. I think he is saying that the comb filtering resulting from two pickups (say neck and bridge) works for low harmonics, but not for higher ones because of a kind of "blurring" resulting from dispersion. ("Blurring" might not be a great description, but it is all I can think of now.) But your decay time argument is right. At a high enough harmonic, or frequency, the pattern is never set up because the energy is gone before enough round trips can occur. But as long as the energy is there, I think it does. A given string harmonic corresponds to a very narrow frequency range, and so there is a well defined phase velocity. I looked some more and was able to find confirmation from PRS that the NF DD pickups do actually use magnetic pole pieces: "The new Narrowfield DD’s continue PRS’s proprietary Narrowfield pickup platform, but trade the Narrowfield’s traditional stairstep design for a mixed magnet/steel pole piece design and a slightly deeper bobbin" Separately from that, I wish I had a gauss meter or something I could use to test the Godin Tetrads. I can say that metal sticks much harder to the blades of the neck rails than they do to the pole pieces on my Duncan Antiquity Surfers (A5), and then metal sticks much harder to the bridge rails than do the neck rails. The bridge rails also have a noticeably different color and texture than the neck rails, so I assume they're different alloys. Given that they seem much more magnetic than my Strat pole pieces, is it likely that these rails are magnets? The pickups are fully epoxy filled so I can't determine any details from the bottom.
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Post by aquin43 on Mar 14, 2024 9:15:13 GMT -5
On reflection, I think that the truth of the matter is that because the wave velocity increases with frequency, the wavelengths of the upper harmonics are not exact submultiples of the fundamental wavelength and don't fit exactly into the string length so the simple static pattern is never quite established until the upper harmonics have decayed.
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Post by ms on Mar 14, 2024 11:14:43 GMT -5
On reflection, I think that the truth of the matter is that because the wave velocity increases with frequency, the wavelengths of the upper harmonics are not exact submultiples of the fundamental wavelength and don't fit exactly into the string length so the simple static pattern is never quite established until the upper harmonics have decayed.
The wavelengths of the harmonics are determined by the length of the string, and then the frequencies are a function of this length. You can measure the frequencies of the harmonics, and you will find that they are not exact multiples of the fundamental. Or, another way to say it: in the string vibration problem, the geometry of the system is input, and the frequencies of vibration are output.
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Post by ms on Mar 14, 2024 11:22:42 GMT -5
I looked some more and was able to find confirmation from PRS that the NF DD pickups do actually use magnetic pole pieces: "The new Narrowfield DD’s continue PRS’s proprietary Narrowfield pickup platform, but trade the Narrowfield’s traditional stairstep design for a mixed magnet/steel pole piece design and a slightly deeper bobbin" If I understand this right, then you could argue that the steel pieces between the magnets guide flux from the vibrating string to the bottom of the extra deep bobbin. But it would appear that the sound of a humbucker is not strongly determined by the two sampling regions as the more than half century old pickup myth states.
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Post by sumitagarwal on Mar 14, 2024 11:37:42 GMT -5
I looked some more and was able to find confirmation from PRS that the NF DD pickups do actually use magnetic pole pieces: "The new Narrowfield DD’s continue PRS’s proprietary Narrowfield pickup platform, but trade the Narrowfield’s traditional stairstep design for a mixed magnet/steel pole piece design and a slightly deeper bobbin" If I understand this right, then you could argue that the steel pieces between the magnets guide flux from the vibrating string to the bottom of the extra deep bobbin. But it would appear that the sound of a humbucker is not strongly determined by the two sampling regions as the more than half century old pickup myth states. This paper seems to go into some detail on that question, but from what I can tell the aperture for single coil versus humbucker seems to be a bit of an assumption here? till.com/articles/PickupResponse/index.html
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Post by aquin43 on Mar 14, 2024 12:22:30 GMT -5
On reflection, I think that the truth of the matter is that because the wave velocity increases with frequency, the wavelengths of the upper harmonics are not exact submultiples of the fundamental wavelength and don't fit exactly into the string length so the simple static pattern is never quite established until the upper harmonics have decayed.
The wavelengths of the harmonics are determined by the length of the string, and then the frequencies are a function of this length. You can measure the frequencies of the harmonics, and you will find that they are not exact multiples of the fundamental. Or, another way to say it: in the string vibration problem, the geometry of the system is input, and the frequencies of vibration are output. Yes, of course you are correct. The standing wave conditions are satisfied by a wave having an integer number of half cycles and the exact frequency is determined by the wave velocity which depends to a degree upon the wavelength.
The wavelength dependency makes the frequencies inharmonic so that the overall shape of the composite wave changes with time.
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Post by ms on Mar 14, 2024 13:54:48 GMT -5
If I understand this right, then you could argue that the steel pieces between the magnets guide flux from the vibrating string to the bottom of the extra deep bobbin. But it would appear that the sound of a humbucker is not strongly determined by the two sampling regions as the more than half century old pickup myth states. This paper seems to go into some detail on that question, but from what I can tell the aperture for single coil versus humbucker seems to be a bit of an assumption here? till.com/articles/PickupResponse/index.htmlRight, it is not the width of the pickup, as he says. But beyond that, whether the sampling window is 4 mm or 17 mm just does not make that much difference. Too much larger than that, though, and you will see a significant loss of higher harmonics, especially on E6.
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Post by ms on Mar 14, 2024 13:56:36 GMT -5
The wavelength dependency makes the frequencies inharmonic so that the overall shape of the composite wave changes with time. And non-linearity in the signal chain could make this important.
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