Original Message:
Sent: 1/22/2024 2:58:00 AM
From: Geoff Sykes
Subject: RE: Sensor Position Invariance. YouTube Video
Steve --
If I wasn't interested I would not be participating in this conversation.
I am not arguing with you, nor am I trying to persuade others either way. Along with others, I am asking questions that you choose to get defensive about instead of addressing. And you get to do that. But honestly, my questions have not specifically even been aimed at you. I was hoping for other techs to expand on the issues I was raising. Halfway expecting to be told my math, my logic and my tuning goals were wrong.
I think your invention is a marvel. And it's not the first time I've said so. But it's not for me as you are currently marketing it.
In order not to start an argument, which I'm really bad at, I have responded to you privately. I will continue to monitor this thread, (who knows. I might learn something. 🙂), but I have no further need to participate.
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Geoff Sykes, RPT
Los Angeles CA
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Original Message:
Sent: 01-21-2024 23:35
From: Steven Norsworthy
Subject: Sensor Position Invariance. YouTube Video
Geoff,
Do you know Bill Shull? I presented at his PTG last week. Bill was impressed when I demonstrated on his Steinway B how I tuned unisons string by string at a time and nailed them to zero cents. Call Bill and talk to him. Paul McCloud has tuned hundreds of pianos with it. He is not on the take and is not a company rep. He will honestly tell you. His customers can all hear the difference. What more can we say?
Keep it simple: if you think this is not for you, then no need to keep writing and arguing but if you keep writing because you want to dissuade others, that is another matter left for private communication but everyone shoud be able to make up their own independent mind without someone who is uninterested trying to persuade his peers. I don't get that.
Many are wiling to try it. Some will just imagine it is not practical and cannot hear the difference. In my class audio examples, everyone can hear the difference. You don't know until you try. If you have not heard the difference and experienced the advantages, how can you presume?
Can see you at Faust Harrison tomorrow night at the Orange County PTG if you want to come over.
Steve
Original Message:
Sent: 1/21/2024 9:51:00 PM
From: Geoff Sykes
Subject: RE: Sensor Position Invariance. YouTube Video
I believe that most of us here understand what you are proselytizing with the graph and measurement results of your invention. And I don't think many of us have any argument against what you are demonstrating. In fact, bravo on your accomplishments! My point, however, is that I find that I am not alone in questioning the usefulness of these data, and the need of such accuracy as your device purports to reveal, in the real world. A 0.25¢ inaccuracy between two strings in a unison, at A4, results in a beat rate of one full cycle beat about every 16 seconds. While that may be interesting data in the lab, it's meaningless in the real world. And any tuner that can't get two strings of a unison to within less than one cent of each other is not listening to their work very carefully. Regardless of the accuracy of whatever ETD we may be using, or the method chosen to capture the vibrations of the strings, if we're not listening to the results, as the final test, in order to achieve the best acoustically audible sound we hear with our ears, we're not doing our job. And any tech that is relying on your, or any device for that matter, to give them even an acceptable tuning is, again, not listening. Regardless of our tools, we tune for our ears, not the tools.
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Geoff Sykes, RPT
Los Angeles CA
Original Message:
Sent: 01-21-2024 18:32
From: Steven Norsworthy
Subject: Sensor Position Invariance. YouTube Video
Nathan,
I am just continually baffled why some tuners want to start out with a large error, and of course the sigma increases more at the extreme ends, so that you get more outliers many cents off?
One starts with an error, a much larger error from the acoustics-based signal processing, as I have shown with prior posts and real data.
Then we know the piano drifts from that tuning naturally. Then we get an even larger error over time and drifting.
Do we really want that, when we now know there is a new device that is basically invariant to begin with, that helps the ETD resolve acoustic interferers at the high end, and define more partials at better resolutions at the low end as well?
A lot of scientific research and engineering effort went into this. The new research I am showing basically does not exist in the literature. It is my job as a diligent researcher to know the prior art. If you think I have missed some prior art and making claims that are not true, then tell me please.
How do I know as a practical matter that these things are relevant? Some highly respected people are testing out the device and confirming what I say is indeed the case.
Nathan, if you are genuinely interested in my 'class' then please have your local PTG president contact me, as I have been successfully offering the class to many monthly PTG groups over zoom.
Respectfully submitted,
Steve
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Steven Norsworthy
Cardiff By The Sea CA
(619) 964-0101
Original Message:
Sent: 01-21-2024 18:10
From: Nathan Monteleone
Subject: Sensor Position Invariance. YouTube Video
Indeed that is the correct definition of Standard Deviation. However, Standard Deviation from all 88 notes isn't a great way to measure the quality of a tuning, for a couple reasons:
- We don't listen to all 88 notes at once. What we care about is how much error there is in any given musical interval, and in practice the slower beating ones tend to stick out a lot more readily if they aren't correct.
- The human ear is more tolerant of errors in the extreme ranges of the piano than it is in the middle section. Standard Deviation assumes all the samples are of equal importance, and in this case they're not. Taking a concrete example, let's grab the mid section of the piano from C2-C6 (49 notes), with 0.5c std dev per note as before. You'd get a standard deviation of 3.5c. Adding the rest of the notes in, isn't going to make the tuning objectively worse -- most of the errors will fade into insignificance -- but the standard deviation goes up to over 5c as you mentioned.
I accept what I assume to be your basic point -- it's worth reducing the error in measurement to something well below our aural tolerance for error, because it reduces the chance that other sources of error (ex. slight tuning instability) will push the total error into the range that we can actually hear. A dirt simple illustration of that problem (albeit one that's a little out of date) is going into the tuning exam with a pitch fork that's 0.9c sharp. Assuming you don't know this and try to match the fork exactly, you've dramatically increased your chances of failure vs. using one that was correct. In fact Standard Deviation would be an appropriate way of qualifying just how much you decreased your chances.
That being acknowledged, please don't continue to imply that the standard deviation over 88 notes is meaningful. Intended or not, it yields big scary numbers (over five cents!) that do not reflect the real-world consequences of the errors we're talking about.
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Nathan Monteleone RPT
Fort Worth TX
(817) 675-9494
nbmont@gmail.com
Original Message:
Sent: 01-21-2024 17:17
From: Steven Norsworthy
Subject: Sensor Position Invariance. YouTube Video
On the Gaussian Curve, more numbers you have, the greater the probability of finding outliers at higher sigmas. It boils down to increasing probabilities of outlier.
One sigma is 34% on each side of the mean. Two sigma is 13.5% more on each side. Three sigma is 2.35% more on each side.
If you had 100 notes, and 1 cent was sigma, then 1 cents sigma would mean that 68 notes would be 1 cent off or less
Then 27 notes would be between 1 - 2 cents off
Then 5 notes would be between 2 -3 cents off
Do you want to be off that much somewhere? I don't. Why? Yes, you are increasing your probability of greater out-of-tune-ness across the range.
It's actually far worse then this, because the lower you go in Hz, the more difficult it is for the ETD to keep the same 'cents' accuracy since the deviation in Hz is decreasing accordingly, by log(2).
In the high register, as I have been painfully showing, the ETD has a harder time resolving close-up acoustic interferers.
Original Message:
Sent: 1/21/2024 5:13:00 PM
From: Nathan Monteleone
Subject: RE: Sensor Position Invariance. YouTube Video
> So let's say your standard deviation error is 0.5 cents from acoustic interference. The square root of 88 is 9.38, so if you have increased the probability of the spread of out-of-tune-ness by at least 5 cents or more.
I don't see how that's a relevant number. Tuning errors don't compound when you're using an ETD, the way they tend to aurally.
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Nathan Monteleone RPT
Fort Worth TX
(817) 675-9494
nbmont@gmail.com
Original Message:
Sent: 01-21-2024 14:10
From: Steven Norsworthy
Subject: Sensor Position Invariance. YouTube Video
Norman and Peter,
A couple of things:
As stated earlier, the loss of power on the attack comes from the 180-deg phase cancellations starting with the upper partials and finally with the fundamental. You can only compare the loss of attack power by doing an A-B back-to-back comparison. I play these for the classes and people are shocked at the difference. If you just are tuning without the comparison, you would not necessarily know. I share a story with you. I have demonstrated this for more than one top tuner, concert level I might say. You need to be on a top-quality concert grand piano where everything is all lined up, and yes, it is very noticeable. The concert tuner got to 0.4 cents on the unisons, as I measured it afterwards. Then I dialed it to 0.1 and he exclaimed the he had never heard that kind of sound before!
Look, I am just saying that the time has come for us to have a reference level way of tuning without variances, repeatable, reliable, not subjective. Why not?
The other thing I keep posting on is the ETD's inability to resolve acoustic smearing in the frequency analysis. Acoustic interference is most exemplified with false beats that are only a few Hz apart. The sensor cannot 'hear' the acoustic interference. It does, however, 'see' the mechanical false beats of 'vertical minus horizontal' frequencies that are partly due to poor bridge pinning or bad wire.
You also must remember that even with non-unison issues from note to note, if the acoustic variability that cannot get resolved in the ETD produces an error of 1 cent, the standard deviation of accumulations of all these errors across the piano is multiplied statistically by the number of notes on the piano. So let's say your standard deviation error is 0.5 cents from acoustic interference. The square root of 88 is 9.38, so if you have increased the probability of the spread of out-of-tune-ness by at least 5 cents or more. Why do you want to start out with this kind of error, knowing you are statistically increasing it as you go? On top of that, you know the piano will spread due to playing and environmental changes. You start out with unnecessary errors, and now the spread over time is even greater! It makes no logical sense if you have a method that starts out with minimal error!
I need customers who want to participate in the raising of the bar. That was Paul McCloud's term when he started using this new method.
Does it make a difference on lesser pianos? Ask Paul, and he will tell you it does, and his customers are telling him their pianos simply sound clearer and cleaner than before.
Perhaps my device will catch on with a new generation of tuners who want to get pristine tunings from the get-go in their emerging careers. That is probably the path forward.
My first two customers were young tuners who have not yet passed their tuning exams and are tuning in noisy environments.
We shall see how long it takes and how much teaching effort it takes to get on a new standard of tuning. I would love to be part of that.
Respectfully,
Steve
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Steven Norsworthy
Cardiff By The Sea CA
(619) 964-0101
Original Message:
Sent: 01-21-2024 13:45
From: Norman Brickman
Subject: Sensor Position Invariance. YouTube Video
Steven, thank you for the kind offer of a Zoom session of your class. Appreciated, but I'll hold off for now.
BTW, in my post I was targeting the tuning of the piano, not tuning unisons. And as I read Geoff and Nathan's posts, I think they were doing the same.
Good point on tuning unisons, and the risks with inaccuracies. I don't recall having heard the effect that you describe in my tuned unisons. The implication in what you describe, though, might be that my (and other's) accuracy in tuning unisons already is of greater accuracy (than with tuning most other non 1:1 intervals) -- considering all the coincident partials available to listen to when tuning a unison!
Regards, Norman
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Norman Brickman
Potomac Piano Service
Potomac, Maryland
potomacpiano@verizon.net
https://potomacpiano.com
(301) 983.9321
Original Message:
Sent: 01-21-2024 13:37
From: Peter Grey
Subject: Sensor Position Invariance. YouTube Video
Someone correct me if I'm wrong on this but I'm pretty sure that virtually all the good ETDs are capable of .2 cent or less accuracy. What I think Steve has been trying to say is "it's not the ETD per se, but rather the microphone". So the ETD's "accuracy" is subject to the stability and repeatability of the mic input. IOW to use computer lingo: GIGO.
Of course I know that we're talking about micro units here, but in typical piano technician nit-pickyness over ridiculously small details, his point is about reducing input error as much as humanly (and technologically) possible. What is implied here (to me) is that a good ETD can get "close enough" because it's "hearing" is basically on par with a good trained human "ear". But a good ETD coupled with this new device can now do what no "human ear" can do.
The question is: "Is that important to me?" Or am I perfectly content with what I'm doing now? In which case I need not be concerned with it.
Again someone correct me if I'm out in left field here.
Peter Grey Piano Doctor
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Peter Grey
Stratham NH
(603) 686-2395
pianodoctor57@gmail.com
Original Message:
Sent: 01-21-2024 12:18
From: Steven Norsworthy
Subject: Sensor Position Invariance. YouTube Video
Dear Norman and Geoff,
This is the picture of what Norman has described. It was done months ago in preparation of my course which I have given to many PTG groups. It is a picture of an A4 where one of the three usisons is mistuned by one cent, or 0.255 Hz. It shows exactly what is happening as the power is immediately sucked out in the first 1/2 second, and the 180-deg crossings of the harmonics are kicking in followed by the first 1/2 cycle 180-deg crossing of the fundamental in 2 secs, and the rebound 2 secs later, the so-called 'bloom' which is not really a bloom but a re-phasing of the next 1/2 cycle where the phases realign.
It is VERY audible when compared to the ideally tuned unisons. I play these audio files for the class. Everyone, 100% of the tuners, agree in the class. I am happy to offer my class to both of you on a zoom session.
Respectfully yours,
Steve
------------------------------
Steven Norsworthy
Cardiff By The Sea CA
(619) 964-0101
Original Message:
Sent: 01-21-2024 11:47
From: Norman Brickman
Subject: Sensor Position Invariance. YouTube Video
Geoff, I also agree with your feeling that 0.25¢ accuracy numbers are "way beyond real world expectations," if I understand you correctly. For example, I estimate that near A440, where there is roughly 25 Hz to the semi-tone, working with a test of major third (M3) progressions (during an aural tuning), the best that I can "give" myself is a one beat-per-second coincident partial resolution in the progression test. With the M3 being 5:4 that leads to about 0.25 Hz or approximately 1¢ accuracy for one of the notes of a two-note M3 interval. On a good day! Regards, Norman.
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Norman Brickman
Potomac Piano Service
Potomac, Maryland
potomacpiano@verizon.net
https://potomacpiano.com
(301) 983.9321
Original Message:
Sent: 01-21-2024 11:14
From: Paul McCloud
Subject: Sensor Position Invariance. YouTube Video
"Can anything but a very sensitive machine tell, or even care for that matter, if a tuning is more than 0.2¢ off?". Well, unless you have the experience of tuning to this level, you might not know how it sounds. Once you hear it, when there is no beat at all, consistently, then you have to admit that what you've been doing is not as good as it could be. We don't wait long enough while tuning unisions, for example, to hear a slow beat. By ear, it takes too long to hear it, so we just don't take the time to do it. But if your app can give you that information, then you can make corrections to get within that range +- .2 cents very quickly. You do hear it. And when you're done with the tuning, you'll have far cleaner unisons and fewer notes to touch up. For me, tuning the best unisons as possible has always been the goal. If I'm inviting the client to sit down and play the piano when i'm done, I cringe when I can hear a unison that's off. Of course, it's going to go out as time goes on. But if you've got it dialed in, it will be in good tune longer. I've done tunings where I did some of the unisons by ear, then compared later to the ones I did string by string. Later, I found that the aural ones weren't as good as I thought they'd be. I had to touch them up again. There's a leeway, an imperfection, in tuning unisons by ear. Much like setting an octave A3 to A4. By ear, you can get close. But it's not accurate enough. You have to check by comparing beats with F3. Where is that check with tuning unisons? There isn't any as far as I know. We just do the best we can, wait a few moments, and it's good enough.
All I can say is, for me it's worth the little extra time it takes.
------------------------------
Paul McCloud, RPT
Accutone Piano Service
www.AccutonePianoService.com
pavadasa@gmail.com
Original Message:
Sent: 01-21-2024 01:42
From: Geoff Sykes
Subject: Sensor Position Invariance. YouTube Video
"...But I know it's not possible for me to get.2 cents by my ears alone."
And I ask the question, again. Can anything but a very sensitive machine tell, or even care for that matter, if a tuning is more than 0.2¢ off? Using A440 as an example, (because the math is simple), where a 4¢ change is equivalent to about 1 Hz, a +0.25¢ inaccuracy would result in A4 being at 440.0625 Hz. Roughly 1/16th of 1 Hz. Lasting accuracy at that level of precision is way beyond real world expectations, I think.
FWIW, I use RCT and, including aural checks after I have completed the tuning, it takes me about 90 minutes, (plus or minus, depending), to put a stable and clean tuning on a piano that is not also requiring a pitch adjustment. Is it a concert level tuning? Perhaps, maybe at times, but I'm not sure how to even define, or apply that requirement to anything other than a great piano, kept in a supremely stable environment and serviced at least every day or so.
Any machine that can detect two or three decimal point accuracy in tuning might be useful in a lab but is, in my opinion, overkill in the field. Aiming for that 0.2¢ accuracy is working way too hard and I suggest that if we learned to listen carefully beyond what the ETD may be telling us we would consistently achieve close enough to that anyway.
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Geoff Sykes, RPT
Los Angeles CA
Original Message:
Sent: 01-20-2024 16:01
From: Paul McCloud
Subject: Sensor Position Invariance. YouTube Video
From my experience using the Pianosens, I suspect that the ETD's are not as accurate as we think because they rely upon microphones in our phones. The results are mostly good, but can often be improved with aural checks, which I believe is partly due to the mic's sensitivity to extraneous sounds. The Pianosens eliminates that problem. But still there can be anomalies which need to be addressed.
As far as the amount of time it takes to tune a piano, obviously there are many factors involved. Using the sensor, a piano that is less than 5 cents flat or sharp I can tune in a little more than an hour and a half. But if I tuned it last week, it would be less. And it also depends how close you want to make it. I tune to within.2 cents, so that level of accuracy takes more time, and you have to do string by string if you want to want the best result possible. I'm not tuning aurally, so I can't comment on the time it takes for an experienced aural to tune a piano. It might take less time than I do. But I know it's not possible for me to get.2 cents by my ears alone.
Sent from my iPhone
Original Message:
Sent: 1/19/2024 4:19:00 AM
From: Steven Norsworthy
Subject: Sensor Position Invariance. YouTube Video
I have 'exposed' the fact to help piano tuners understand the large variance that comes from moving the microphone of the ETD, causing a large variance on the tuning measurement by a worst case of more than 1 cent, this being an intolerable amount, causing the tuner to no longer trust the ETD. I cannot tell you the number of 'private' conversations I have gotten from tuners who 'know' this to be an issue and have been distrustful of the ETD's. Well, thankfully, there is a solution.
In prior posts, I have been stating the invariance of the sensor, and people want to know how small changes along the position of the string will affect the tuning measurement in their ETD when the sensor is used. This is a fair question and deserves an answer.
This video demonstrates that the sensor, when kept to an area between the hammer and the termination of the string, is invariant on measurement. The result is an astoundingly near-zero variance. Even more specifically, when I process the captures into Matlab and further analyze the variance, I see the range is from 0.03 to 0.08 cents!
Also, yes, device is available. You can use it with confidence. It is a very high tech device employing the best design practice found in state of the art sensors used in space systems and is produced in a DoD-certified facility.
https://youtu.be/xUfOnQWWoD4
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Steven Norsworthy
Cardiff By The Sea CA
(619) 964-0101
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