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  #46  
Old 05-24-2018, 06:17 PM
DesertTwang DesertTwang is offline
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I don't hear the thunk, either, but the first place I'd look would be this lady's picking style. I have to admit I don't find it particularly smooth or sensitive, so maybe that's part of it.
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  #47  
Old 05-25-2018, 02:39 AM
N+1 N+1 is offline
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Let's make it visible. I recorded the audio from about 0.33s when she begins the slow strum downwards and here's the Audacity display:



You can see the sequence of notes from the first three separate strings at low amplitude. Then she hits the G string, and we get the thunk (marked by an arrow). Then we get the highest two strings (the highest only just visible.)

Then she does a faster strum downwards. You can again just pick out the first three strings, and then again comes the thunk, dominating everything else (marked again by arrow).

So we're not imagining this. It's there loud and clear and in the audio profile - look at the size of those thunks. I don't think it has anything to do with her technique. The thunk is clearly present when all she's doing is strumming down the strings, with no extra weight given to one string or another.
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  #48  
Old 05-25-2018, 03:15 AM
Kerbie Kerbie is offline
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N+1, that's fascinating! Thanks for doing that. Mary is a wonderful player, especially if you like fingerstyle blues... and an AGF member!
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  #49  
Old 05-25-2018, 04:07 AM
N+1 N+1 is offline
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Originally Posted by Kerbie View Post
Mary is a wonderful player, especially if you like fingerstyle blues... and an AGF member!
Gosh Kerbie, I hope she doesn't mind us dissecting this recording in the way we have - I'm conscious that we have rather dissected it to near-extinction in a way she wouldn't have anticipated. On the other hand, she has stimulated an awful lot of discussion about this guitar (and it really is a feature of the guitar, I believe), and how we all hear it differently.

[So if you read this, Mary, please forgive all this sharp focus on a single note - and thank you for putting the recording out there.]
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  #50  
Old 05-25-2018, 04:25 AM
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JayBee1404 JayBee1404 is offline
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OK, I've listened numerous times. I don't hear a 'thunk', but I do hear an open G string that sings out louder than the other five. My guess would be that the G aligns with, and is amplified by, the natural resonance of the body of the instrument.

Nothing that would put me off that guitar if I was in the market for such an instrument but, of course, that's IMHO, and YMMV.
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  #51  
Old 05-25-2018, 07:03 AM
N+1 N+1 is offline
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Originally Posted by JayBee1404 View Post
My guess would be that the G aligns with, and is amplified by, the natural resonance of the body of the instrument.
If you're right, wouldn't that imply poor guitar design - to produce a resonance that emphasises one note so loudly, above all the rest? (Would anyone see that as a good thing?)
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  #52  
Old 05-25-2018, 09:05 AM
funkapus funkapus is offline
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Quote:
Originally Posted by N+1 View Post
Let's make it visible. I recorded the audio from about 0.33s when she begins the slow strum downwards and here's the Audacity display:



You can see the sequence of notes from the first three separate strings at low amplitude. Then she hits the G string, and we get the thunk (marked by an arrow). Then we get the highest two strings (the highest only just visible.)

Then she does a faster strum downwards. You can again just pick out the first three strings, and then again comes the thunk, dominating everything else (marked again by arrow).

So we're not imagining this. It's there loud and clear and in the audio profile - look at the size of those thunks. I don't think it has anything to do with her technique. The thunk is clearly present when all she's doing is strumming down the strings, with no extra weight given to one string or another.
Thanks for doing this -- I was thinking about doing exactly this last night, but life is crazy right now, plus I couldn't figure out the best way to capture the sound in the video.

If you look at the peak we'd associate with the "thunk", one thing that's interesting to me (and goes along with what I think I hear) is that the thunk part seems to have a more rapid decay than the other notes, as if it drops off until what remains is the more expected timbre of the open string decaying as normal. But that's just from eyeballing that image -- I'm not confident of that.

One other thing I was thinking about doing in Audacity that you might do if you have the time: highlight the time period right around the thunk and ask Audacity for a power spectrum (frequency analysis). Do the same thing for the previous tones on the lower strings. One expects to see the fundamental, the overtone series at lower amplitudes, and a little bit mixed in from the strings plucked previously that are still vibrating (from their sustain). I'm curious whether the power spectrum for the open G string looks significantly different from the others (e.g. a *much* stronger fundamental, or an unusual array of overtone amplitudes, or whatever)
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  #53  
Old 05-25-2018, 09:09 AM
funkapus funkapus is offline
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Originally Posted by Wistah View Post
I hear both the fret buzz and the g-string thunk that the OP describes. The G string sounds dead and lifeless when played open. When played fretted, it sounds OK. Could be a bunch of things, but my money is on a worn nut slot.
Hmmm!

This suggestion is intriguing to me, because it would suggest that this is something that would be easily fixed, whereas if it's a property of the build (e.g. a top resonance) then it's hard to imagine a fix that wouldn't affect the rest of the guitar's sound as well. But I feel like I *have* heard it on new guitars before (the second video I posted is of a guitar that was new at that time), so in that case a worn nut slot would be surprising, although not impossible.
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  #54  
Old 05-25-2018, 09:17 AM
Jambi Jambi is offline
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I wonder if this is an example of the frequencies older ears filter out. I would be curious to know ages of people who hear the thunk vs ages of those who can't.

Here's an recent example: https://en.wikipedia.org/wiki/Yanny_or_Laurel
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  #55  
Old 05-25-2018, 09:25 AM
funkapus funkapus is offline
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Originally Posted by Kerbie View Post
N+1, that's fascinating! Thanks for doing that. Mary is a wonderful player, especially if you like fingerstyle blues... and an AGF member!
Oh, I didn't know she was a member here. Mary's one of my favorite players, and a great teacher as well.
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  #56  
Old 05-25-2018, 09:28 AM
Kerbie Kerbie is offline
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Quote:
Originally Posted by funkapus View Post
Mary's one of my favorite players, and a great teacher as well.
She's is! I've had maybe four classes with her, enjoyed them all and learned a ton. Her instructional DVDs are also very good.
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  #57  
Old 05-25-2018, 11:48 AM
charles Tauber charles Tauber is offline
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Quote:
Originally Posted by N+1 View Post
Let's make it visible. I recorded the audio from about 0.33s when she begins the slow strum downwards and here's the Audacity display:


It isn't as simple as that. Yes, Audacity shows a greater amplitude (volume) on the third string. However, the lowest two strings, and maybe the D string, have a lot of buzzing. The buzzing clips the amplitude as it appears in those graphs. I've experienced that in Audacity recordings/analysis that I have done. To get "accurate" results - in amplitude, decay and frequency response - one needs to have buzz-free notes, else one is analyzing the buzzing as well.

It might well be that the G string is the first that isn't diminished/dissipated by the buzzing and, hence, appears as having greater amplitude.

What I predominanetly hear in listening to that sample, again, is a whole lot of bass string buzzing of the bottom two strings, followed by clearer notes on higher strings. The first buzz-free sound is from either the D or G. It might well be that the open G string is louder than the others, but there is such a difference in timbre between the buzzing bass notes and the G string that it isn't what dominates my perception of it.
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  #58  
Old 05-25-2018, 12:17 PM
Alan Carruth Alan Carruth is offline
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If the 'main top' resonance is indeed aligned with the open G string pitch, you'd expect to see more volume in that note for a shorter time: 'thunk'. There's only so much power in a plucked string. When the resonance aligns like that the energy is extracted and turned into sound quickly, so the peak is high but the sustain is shorter. Our ears are not very sensitive to fairly large changes in power (unlike microphones), but we do notice the lack of sustain.

If this is the case you'd expect the same pitch played on another string to do much the same thing. Does it? You can also alter the 'top' resonant pitch, say by adding some weight to the bridge, and see if the problem goes away or changes to another pitch.

Note that this sort of frequency match only effects the string partial that it's aligned with. If the top resonance is at g~196 then the only partial of the played note that will be effected strongly is the fundamental of the open G string. The higher partials can mask that to some extent. That's why most folks don't notice the problem on my guitar that 'warbles' at that pitch; there's enough other stuff going on that you don't notice it.
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  #59  
Old 05-25-2018, 02:29 PM
N+1 N+1 is offline
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Quote:
Originally Posted by Jambi View Post
I wonder if this is an example of the frequencies older ears filter out. I would be curious to know ages of people who hear the thunk vs ages of those who can't.
I'm 70. I know I'm losing some of the high frequencies, but I don't think that's a reason for hearing exaggerated clunks. Or is it?
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  #60  
Old 05-25-2018, 02:34 PM
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Quote:
Originally Posted by charles Tauber View Post
It isn't as simple as that.
Just to be clear: remember I wasn't putting forward an explanation; I was concerned only with establishing some objective evidence for extra loudness emanating from the G string relative to the others. So from that point of view, it actually is as simple as that.

As for the explanation - well I wouldn't expect that to be simple, and I hand that side of it over to experts like yourself. All I claim is that my Audacity snapshot clearly demonstrates what my ears told me: that something isn't right.
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