#121
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I've learned a lot reading this thread. This sort of lively and technical conversation is one of the many reason why I love the AGF.
I do think, however, that Andy's reply has become a bit misconstrued along the way. Picker2 wrote that: Quote:
But it seems to me that Andy is suggesting that a top with a natural resonance hot spot of 320Hz will resonate when either E4 or E5 is plucked (albeit for a short time as Picker2 has convincingly shown)--not that plucking E5 will somehow sympathetically or subharmonically excite E4 as well. In Andy's words: "If a guitar has a natural resonance hot spot around 320Hz, it will vibrate whenever either of these E naturals are played. But what we’ll hear is a mix of 329 or 659 and 320" (emphasis mine). I still question some of his other claims, but I think it's important that we understand exactly what he is (or is not) saying and don't criticize him for claims he is not making. |
#122
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As you see, the fundamental is now at 659 Hz. The 329 Hz (open E-string) is gone, as expected. AND, you still see the body resonant peaks at 108 and 190 Hz. They're always there, no matter what string you play and where on the neck you pluck. Quote:
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Last edited by Picker2; 03-11-2018 at 12:33 AM. |
#123
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Last edited by Picker2; 03-09-2018 at 01:37 PM. |
#124
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But it makes no difference. The frequencies of the notes being played are irrelevant for the excitation of body resonant frequencies. So it does not matter if it's a 329 Hz or a 659 Hz, neither of the two will excite a body resonant frequency of 320 Hz. The only thing that happens is that the two frequencies will be released by the top at various sound levels, depending on the guitar's frequency response curve. If there is a peak around 320 Hz, the 329 Hz will probably sound louder than the 659 Hz, even when the string vibrates at the same amplitude for both frequencies. But it will still be a 329 Hz you hear ringing out, and no 320 Hz along with it. As stated before, the 320 Hz is excited only by the string attack and will merely produce a short 'thud'. (In addition, of course, the hundred-thousand-dollar question remains: how could V-bracing consistently shift the 320 Hz hot spot to 329 Hz?)
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Last edited by Picker2; 03-09-2018 at 01:40 PM. |
#125
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OK seems indeed the octave below is not being reproduced,, but now (as per Erithon) looks like that was not what AP was saying. I admit the wording of his statement was a bit vague at first read But now I have some new questions. First it appears you are using an iPhone app which one ? Because I now would like to see how my guitars graph Not because I care about AP statements one way or the other, just curious about the body resonance . Also after looking at the graphs and (understanding that an iPhone mic and graphing app. may not be the most accurate ) If that's what you are using .... But couple anomalies appear to have arisen. One: on the open E string pluck graph, Is the L Peak : number in the upper left , showing the fundamental or does (L) simply mean "loudest" ? ..If the fundamental, then why is it showing 331 instead 329 ? I certainly hope that does not mean your guitar is inaccurately intonated by 2 Hz ???? Maybe you need V bracing just kidding , I assume the (L) means loudest ?? Because in the new graph with the 12th fret pluck the L Peak is showing 1324 assuming that is twice the fundamental, if it's the fundamental, that would make that 662 Hz ..... so why is the octave above tone louder than the fundamental by what appears to be 3 or 4 db ?????????
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Enjoy the Journey.... Kev... KevWind at Soundcloud KevWind at YouYube https://www.youtube.com/playlist?lis...EZxkPKyieOTgRD System : Studio system Avid Carbon interface , PT Ultimate 2023.12 -Mid 2020 iMac 27" 3.8GHz 8-core i7 10th Gen ,, Ventura 13.2.1 Mobile MBP M1 Pro , PT Ultimate 2023.12 Ventura 12.2.1 Last edited by KevWind; 03-09-2018 at 03:56 PM. |
#126
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I always give my wife a hard time about watching reality tv, but considering how much enjoyment I get out of combing through threads like these, maybe I need to cut her some slack. But hey, at least I'm learning something along the way, right? This is the kind of stuff that makes AGF so addicting!
Stay gold, Ponyboy... |
#127
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Except that "reality TV" is anything but, Terry. It's mostly scripted and directed but without professional actors and actresses and writers.
Here at AGF we engage in a dynamic dialogue, just like any discussion among friends. Threads can take a turn in direction at any moment, and we all learn a lot more about our hobby -- more than who got voted off the island or who got a rose this week. |
#128
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I played a presentation model the other day. It seemed to have a Taylor-ish vibe, but different. It was a nice guitar, don't get me wrong, but didn't blow my world away. That particular guitar sounded very much like a 714ce-cedar. Perhaps the upper frets had more sustain?
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Assuming is not knowing. Knowing is NOT the same as understanding. There is a difference between compassion and wisdom, however compassion cannot supplant wisdom, and wisdom can not occur without understanding. facts don't care about your feelings and FEELINGS ALONE MAKE FOR TERRIBLE, often irreversible DECISIONS |
#129
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The most dramatic example of a sympathetic harmonic vibration I have encountered is while standing next to (like reach out and touch ) 7 Burlington Northern locomotives ramping up to pull 50-70 freight cars out of the yard . It is just short of dropping you to your knees
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Enjoy the Journey.... Kev... KevWind at Soundcloud KevWind at YouYube https://www.youtube.com/playlist?lis...EZxkPKyieOTgRD System : Studio system Avid Carbon interface , PT Ultimate 2023.12 -Mid 2020 iMac 27" 3.8GHz 8-core i7 10th Gen ,, Ventura 13.2.1 Mobile MBP M1 Pro , PT Ultimate 2023.12 Ventura 12.2.1 |
#130
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“The string vibrates at a pitch and is attached to the body, transferring its vibration to a larger surface which will try to vibrate at the same frequency. If the body were so tuned to vibrate at exactly the same frequency as the string, life would be great. However, along with the intended fundamental note, we have overtones, and to a weaker degree, undertones. These are mathematically related other pitches summed together with the intended pitch. If we looked at A 110Hz, we should also have 220 Hz, 330Hz and so on, as well as a half-formed 55Hz.” Now I understand why I misinterpreted his argument about the E string fretted at the 12th string producing also an E4. I think maybe Andy confuses body resonances with string harmonics. In any case, an A string with fundamental of 110 Hz does not generate a half-formed 55 Hz like he states.
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#131
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Your wrong. Check 4.7.2 in your copy of Contemporary Acoustic Guitar Design and Build by Gore and Gilet.
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Fred |
#132
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I think everyone would have been able to swallow this better if AP just said, "they sound better" and left it at that. then, it's just a matter of opinion, when one makes "scientific" statements about an aspect of a guitar, those statements are either true or false, if they turn out to be false, as time goes by and various people with the proper methodology dissect it, it just won't "look" good, regardless of Taylors successes. but in the long run I don't think it will negatively effect them one way or another. really it just gives us something to blather about.
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http://www.jessupegoldastini.com/ |
#133
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Karen
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When I was 5 years old, my mother always told me that happiness was the key to life. When I went to school they asked me what I wanted to be when I grew up. I wrote down, “happy.” They told me I didn’t understand the assignment, and I told them they didn’t understand life. —John Lennon |
#134
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I have drunk the kool aid. Drunken the koolaid, drank from the koolaid? Not sure. But in respect for Taylor's patent I will forgo the V and do a fan brace instead. Don't want any pesky lawyers come knocking around at night.
Think I will go bend some sides.
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Fred |
#135
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I think it is actually smoking the koolaid. LOL! Let us know how that fan bracing shakes up those resonant harmonics or sub-basement resonances, or overdrawn tonics. You get my drift. [emoji41]
Best, Jayne |