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OnlyPure calibration

  • 1.  OnlyPure calibration

    Member
    Posted 11-27-2017 12:58
    Users of Tunelab and OnlyPure

    I've encountered a sticky calibration problem. I posted this on the ptg googlegroup, but I want input from Kent Swafford and Bernhard Stopper, please.

    I just tuned my piano with OnlyPure on my ipad mini 4. Then I play it for a while and the treble is gorgeous but I want to investigate the bass, so I open TuneLab to check the frequencies of selected partials. I look at A4 and Tunelab says it is 3.4-ish cents flat. Verituner agrees: 3.4 cents flat. 

    Hmm, I think to myself - maybe it's something about this iPad, though I know I have it properly calibrated per Tunelab setup instructions. I switch to my iPhone and open OnlyPure for the first time on that device. It shows the A4 as wandering slightly sharp of 440, by 0.07 to .8 cents. So OnlyPure on the iPhone agrees with OnlyPure on the iPad. Again, on the iPhone, both TuneLab and Verituner agree that this note is 3.4 cents south.

    I've uninstalled and reinstalled OP, but it remains in a state where it thinks 439.1 is 440.0. And this is so on BOTH devices, though I have only used it on one device. How can I get OnlyPure calibrated correctly, on both devices?

    Thoughts?

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    jason's cell 425 830 1561


  • 2.  RE: OnlyPure calibration

    Posted 11-27-2017 18:21
    OnlyPure calibrates from the actual piano string. If you want to really be accurate it must be calibrated every time. Here's what I do: Tune A4 with TuneLab (middle string only) then open OnlyPure, switch to calibration mode, play the note, calibrate to it and switch back to Tuning mode. 

    Hope this helps!

    ------------------------------
    "That Tuning Guy"
    Scott Kerns
    www.thattuningguy.com
    Tunic OnlyPure & TuneLab user
    ------------------------------



  • 3.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 11-27-2017 18:31
    Scott, your procedure is correct for the Android version of OnlyPure.

    For the iOS version of OnlyPure, your procedure is correct, except OnlyPure no longer has the Calibrate mode; one simply uses the offset instead.


    ------------------------------
    Kent Swafford
    Lenexa KS
    913-631-8227
    ------------------------------



  • 4.  RE: OnlyPure calibration

    Member
    Posted 11-27-2017 18:46
    Kent, my calibration offset somehow became corrupted. The only cause I can think of is that the first time I used OnlyPure, I wanted NOT to do a pitch correction as well - so I calibrated it to match where the piano was, which was 3.4 cents flat. OP's first use in my world was at A=439.2 ish. Now, it's like a baby duck that thinks 439.2 is its mama. And that same imprint traversed the ether to land in my other device. A very interesting bug. There must be a way to reverse it.

    I know that I can just tap it to what I know is correct, but this generates some mistrust, and I wouldn't want a customer to look at my screen and say "Hey wait a minute, I want 440." "Well, this IS 440, you see, but the software is kind of stubborn about it." I don't think Bernhard would want that either.

    Jason

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    jason's cell 425 830 1561

    On Mon, Nov 27, 2017 at 3:31 PM, Kent Swafford via Piano Technicians Guild






  • 5.  RE: OnlyPure calibration

    Posted 11-27-2017 22:18

    I know that I can just tap it to what I know is correct, but this generates some mistrust, and I wouldn't want a customer to look at my screen and say "Hey wait a minute, I want 440." "Well, this IS 440, you see, but the software is kind of stubborn about it."
    Jason Kanter,  11-27-2017 18:45
    Just for the record Jason, I'm with you. Not so much that the customer would notice but I certainly would. My OCD (Obsessive Compulsive Disorder) would come out and want it to read A440!! 😒😕😬

    ------------------------------
    "That Tuning Guy"
    Scott Kerns
    www.thattuningguy.com
    Tunic OnlyPure & TuneLab user
    ------------------------------



  • 6.  RE: OnlyPure calibration

    Posted 11-27-2017 18:58
    "For the iOS version of OnlyPure, your procedure is correct, except OnlyPure no longer has the Calibrate mode; one simply uses the offset instead." Kent S.

    Hmmm...Well, that's inconvenient.


    ------------------------------
    "That Tuning Guy"
    Scott Kerns
    www.thattuningguy.com
    Tunic OnlyPure & TuneLab user
    ------------------------------



  • 7.  RE: OnlyPure calibration

    Member
    Posted 11-27-2017 18:32
    I know I can do that, but when I do, OnlyPure puts "441.0" in the upper left. You know and I know that it's really 440, but I want OnlyPure to know it, dammit. There has to be a way to reset it. I tried uninstalling and reinstalling but the error remains. And the weird thing is that the error has migrated to my other device, without OP ever being calibrated to anything on that device.

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    jason's cell 425 830 1561

    On Mon, Nov 27, 2017 at 3:21 PM, Scott Kerns via Piano Technicians Guild






  • 8.  RE: OnlyPure calibration

    Member
    Posted 11-27-2017 18:38
    Wait -- "switch to calibration mode"?? I guess I haven't found that mode. Where is it?

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    jason's cell 425 830 1561





  • 9.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 11-27-2017 18:52
    "I know I can do that, but when I do, OnlyPure puts "441.0" in the upper left. You know and I know that it's really 440, but I want OnlyPure to know it, dammit. There has to be a way to reset it."

    Yes there is, on the Android version.
    No there isn't, on the iOS version. This is probably a design decision. After all, OnlyPure's magic does not require it to parse out individual partials; therefore OnlyPure has never had a way of tuning the fundamental of A4 to a frequency of exactly 440.

    "I tried uninstalling and reinstalling but the error remains. And the weird thing is that the error has migrated to my other device, without OP ever being calibrated to anything on that device."

    There is no error. What you are seeing is OnlyPure trying to fit A4 into a temperament, not hit 440. Therefore this discrepancy will vary a bit from piano to piano, depending upon the exact inharmonicity of A4.

    Choose the A4 you wish to use and offset OnyPure to match it. For every piano.

    To tune A4, one could use an external pitch source like a fork or electronic pitch source. One could use another electronic tuning device, probably even a cheap guitar tuner for an accurate 440.

    Or just go with OnlyPure. It's close enough for most situations.





    ------------------------------
    Kent Swafford
    Lenexa KS
    913-631-8227
    ------------------------------



  • 10.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 11-27-2017 20:33
    I've been wrestling with this for a while ever since I put Onlypure, Tunelab and Cleartune on the same Tablet. I also had istrobosoft on my phone (for $10 sheesh!) While the android version of istrobosoft is pretty universally reviled for good reason, Cleartune for free is pretty good and last week I got Pitchlab pro and paid the $3 for the upgrade based on a harpsichord thread on this site. Recently I upgraded to a modern phone and migrated everything to that device (thanks Herr Stopper and Mr. Scott)  I also own an Accutuner III. of them all I only trust the Accutuner. Last Spring I measured A4 on a CFIII ,that I had used to calibrate Onlypure, with all of the above except for pitchlab as I didn't own it yet. With the Accutuner reading the fundamental as 0.0 I got the following results:

    Onlypure 3.9 cents sharp
    Tunelab  .8 cents flat varying down to 1.9 cents flat
    Cleartune 4.5 cents sharp
    Istrobosoft  .5 cents flat varying to 4 cents sharp

    I then measured my A440 fork which is 1.8 cents flat at 75 degrees and dead on at 67 degrees with each. the room was about 75 degrees at the time.

    Onlypure  4 cents flat
    Tunelab  1.5 cents flat
    Cleartune  1.5cents flat
    Istrobosoft  1.1 cents flat varying to 3 cents sharp

    I found that none of the software based tuners were reliable for accurate repeated measurements of a single note.

    In the end you have to decide who you are going to trust as your pitch reference. Almost any cheap quartz metronome has an accurate A440 tone as measured with an Accutuner. The variability of the software tuners doesn't bother me so much as I'm tuning by ear while I'm using them. It should be noted that of the software tuners I only use tunelab and onlypure for piano tuning as the others are essentially toys. If however I only tuned electronically I wouldn't want to rely on either of them. I much rather see someone use an Accutuner in that case.

    Hope I haven't gotten too far off topic here but I've been carrying around this data in a little notebook for 8 months and now I can finally toss it:-)

    ------------------------------
    Karl Roeder
    Pompano Beach FL
    ------------------------------



  • 11.  RE: OnlyPure calibration

    Posted 11-27-2017 22:09

    Hope I haven't gotten too far off topic here but I've been carrying around this data in a little notebook for 8 months and now I can finally toss it:-)
    Karl Roeder,  11-27-2017 20:32
    It all seems pertinent to me. I always use TuneLab as my pitch standard and it's been dead on for me. I have done an internet calibration that takes several hours though. I use the Android version. Maybe this calibration isn't possible with the iPhone/iPad version.

    ------------------------------
    "That Tuning Guy"
    Scott Kerns
    www.thattuningguy.com
    Tunic OnlyPure & TuneLab user
    ------------------------------



  • 12.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 11-28-2017 00:18
    Hello Mr. Roeder,

    I appreciate your list, and find it interesting. However, I do want to point out that you assume all app based ETDs are inaccurate pitch sources. But missing from your list is the VertiTuner and the CyberTuner.

    While I've not yet tried the VertiTuner, I've found the CyberTuner to be very good both for pitch and repeatability. CyberTuner will recalibrate pitch whenever it has internet connection (assuming you have a subscription), and it takes a whooping two seconds (using my WiFi). Measured against a fork and the Accu-Tuner. Repeatability is excellent, and consistent. I can pound a note repeatedly, and as long as the test blows are all of the same force (ie, not mf, ff, m, f, etc.) I get the same readings. 

    Only trying to say one can't lump all the ETDs together, because they are not all equal. Just my two cents.

    ------------------------------
    Benjamin Sanchez
    Professional Piano Services
    (805)315-8050
    www.professional-piano-services.com
    BenPianoPro@comcast.net
    ------------------------------



  • 13.  RE: OnlyPure calibration

    Posted 11-28-2017 09:19
    The Verituner app has a built-in calibration function. From the User Guide: "When you first install the Verituner App, the accuracy of your iOS device's A440 pitch will typically be well within 1.0 cent, which is suitable for most piano tuning. To increase the accuracy even more precisely, a calibration can be done using a laboratory-grade frequency source. (For more on calibration, see Robert Scott's informative article, "Calibration of Pitch References" in the August 2001 Piano Technicians Journal.)

     
    To illustrate how it works... 


    I bought a new iPhone recently. After installing the app, I opened the calibration function, and opened this webpage:

    https://en.wikipedia.org/wiki/A440_(pitch_standard)  

    It has a 3-second recording of A440. (I don't know that it's "laboratory-grade" but I trust it's a good source.) I played it several times while adjusting the Verituner to show its reading of the pitch source at 0.00. The iPhone read it at 0.64¢ sharp, so the Verituner is calibrated +0.64¢ for my particular device.

    Once set, there is no further need to recalibrate. Set it and forget it.

    ------------------------------
    David Bauguess
    Grand Junction CO
    970-257-1750
    ------------------------------



  • 14.  RE: OnlyPure calibration

    Member
    Posted 12-04-2017 13:46
    Whenever someone says "this website has a reliable A-440 reference" we should remember that a website does not transmit a frequency - ever.  It is technically impossible. It transmits instructions to your computer on how to make a frequency.  Those instructions are interpreted by the sound system in your computer or mobile device.  It is your computer - more specifically, the sound hardware in your computer - that is actually responsible for the accuracy of the tone produced - not the website that provided the instructions.  It is possible that one computer will play the tone a little sharp and another computer, accessing the same website, could play the tone a little flat.  When you evaluate the accuracy of a tone generated by a website you are really evaluating the accuracy of whatever computer you are using to access that website.

    This was easier to demonstrate 20 years ago than it is now because manufacturers of modern computer sound systems have improved the accuracy of their quartz reference so that even without external calibration, these computers and mobile devices are very close.  It is hard to find a new device that actually needs calibration to be accurate enough for our purposes.  But if you do find a device with a significant uncalibrated pitch error, you will be able to see that so-called reference pitch websites do not produce the same tone in those devices.

    ------------------------------
    Robert Scott
    TuneLab
    Hopkins MN

    ------------------------------



  • 15.  RE: OnlyPure calibration

    Posted 11-28-2017 05:26
    Jason,

    OnlyPure does not measure partial 1 on A4 by design. It rather interprets some sort of "OnlyPure Effective Pitch" (OEP) by a proprietary autocorrelation function, where OEP deviates from partial 1 pitch with increasing nonlinearity (inharmonicity, damping). On a signal with harmonic partials, OEP and partial 1 pitch is exactly the same. With former versions (still there with the Android version) it was possible, to "calibrate" this deviation out. Generally calibration was also necessary, because soundcards were not consistent enough, which is no longer true on the newer devices. The drawback by calibrating the difference of OEP and partial 1 caused by nonlinearity is that with a harmonic signal, OnlyPure would read a difference between OEP and partial 1 then, which makes no sense and is the reason why the calibration has been pulled off.

    Kent Swafford correctly outlined how to deal with this.

    ------------------------------
    Bernhard Stopper
    Klavierbaumeister
    Tuebingen
    ------------------------------



  • 16.  RE: OnlyPure calibration

    Member
    Posted 11-28-2017 14:30
    Bernhard, thank you for chiming in. Your answer makes sense and yet it does not account for the size of the deviation that I find. The inharmonicity of the partials cannot account for 3.4 cents difference in the fundamental. Kent says that even without tapping the offset to match a known 440, one can just start tuning and it will be very close. Not so in my case. 
    To review: the first time I used OnlyPure, I did tap the offset to match the given piano because I did not wish to do a pitch correction. The second time I used it, I first raised the pitch using Tunelab's overpull function, so the piano was now close to A4=440. Then I switched to OnlyPure, whose offset display showed 440.0, but the actual A4 string's green triangles were 3+ cents off to the right. If I just trusted OnlyPure, I would have retuned this piano at 439.14.
    When I tapped the offset to match the correctly tuned A4 string, the displayed number in the upper left of the OnlyPure screen was 440.9 (which is 3.4 cents sharp).
    I understand that this displayed number is not germane to the actual tuning: that I use the offset buttons to match A4 to a trusted source, and proceed to tune from there. That's fine. But something happened with my instance of the software, which resulted in the displayed number being wrong. The size of the discrepancy is not adequately explained by your description of OEP. This is an error that should be investigated and fixed. 

    Perhaps there is a clue as to what happened, in the odd fact that the same unwitting offset that I describe above (on an iPad) appears also in my iPhone, which I never "calibrated."
    It seems that the first tuning sets a stamp on the software.

    Please comment again, after which I expect further discussion will lead to diminishing returns. 

    Cheers
    Jason Kanter

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    jason's cell 425 830 1561

    On Tue, Nov 28, 2017 at 2:25 AM, Bernhard Stopper via Piano Technicians Guild






  • 17.  RE: OnlyPure calibration

    Posted 11-28-2017 15:08
    A deviation of 3.4 cents you encounter on A4 is of a correct magnitude for OEP (OnlyPure effective pitch) for a typical piano scale, so there is no error with your devices or your software. OEP functionality is essential for the ability that OnlyPure can deal with piano nonlinearity without the need of pre-measuring notes before the tuning process or OnlyPure's ability to tune pianos with different nonlinearity profiles nicely together by using the same OEP for both instruments.

    ------------------------------
    Bernhard Stopper
    Klavierbaumeister
    Tuebingen
    ------------------------------



  • 18.  RE: OnlyPure calibration

    Member
    Posted 11-28-2017 15:13
    Thanks Bernhard. I will continue to explore. As others have reported, the unisons are the best I have ever done, and the treble is extraordinary. 

    Jason Kanter 






  • 19.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-01-2017 10:56
    I don't understand why it is essential for the base pitch (first partial) of A4 to be variable in order for the software to work. I especially don't understand how a variance of over 3¢ can possibly be acceptable. A4 is very close the the middle of the piano, so why can't it serve as the nexus around which the rest of the tuning is crafted? Alternately, why not include within the software the ability to play A4 first, and have the software automatically read the profile of that note and adjust the inner pitch of the template?

    The user should not be responsible for finding some other way (outside of using the app) to assure that the pitch of the tuning will be accurate. Accuracy of 0.1¢ isn't really important, though it is desirable that that degree of accuracy is available, but + or - 3.0¢+? Making the piano I am tuning compatible with an additional piano played at the same time comes up very rarely, and I would say that that ability should be an additional optional feature rather than a major driving force in designing the software.

    ------------------------------
    Fred Sturm
    University of New Mexico
    fssturm@unm.edu
    http://fredsturm.net
    http://www.artoftuning.com
    "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
    ------------------------------



  • 20.  RE: OnlyPure calibration

    Posted 12-01-2017 11:03
    Thanks for recommending Pitchlab Fred.  Nice little app, Added it to my arsenal. 
    -chris






  • 21.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-01-2017 13:39
    Just to add another specific observation to Jason's that opened this thread, I tuned a couple Steinway Ds this morning. A4 spot on at 440. Measured with OnlyPure. It told me the note was about 5¢ sharp. I calibrated OnlyPure (changed the 440 window) and it needed to be set to 441.1 - 441.3 to read an A440 as being in tune. This is not a minor quirk.

    ------------------------------
    Fred Sturm
    University of New Mexico
    fssturm@unm.edu
    http://fredsturm.net
    http://www.artoftuning.com
    "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
    ------------------------------



  • 22.  RE: OnlyPure calibration

    Posted 12-01-2017 14:53
    Ok i think i need to try to explain further:

    Quote Fred Sturm: "I don't understand why it is essential for the base pitch (first partial) of A4 to be variable in order for the software to work. I especially don't understand how a variance of over 3¢ can possibly be acceptable."

    There seem to be a misunderstanding: OnlyPure pitch information is not base pitch (first partial) of A4. It is some sort of autocorrelation function of the whole tone, that means an integral pitch impression including higher inharmonic frequencies and damping effects. So what is shown in OnlyPure for the pitch is a value that corresponds to a pitch impression compared with a pure harmonic tone of that pitch value.

    Quote Fred Sturm: "Just to add another specific observation to Jason's that opened this thread, I tuned a couple Steinway Ds this morning. A4 spot on at 440. Measured with OnlyPure. It told me the note was about 5¢ sharp. I calibrated OnlyPure (changed the 440 window) and it needed to be set to 441.1 - 441.3 to read an A440 as being in tune. This is not a minor quirk."

    As mentioned before, OnlyPure pitch information is not pitch of partial 1 of A4, but a pitch impression compared with a harmonic tone: In the example above of the Steinway D this would mean the following: An A4 tone of a Steinway D with an A4 partial 1 tuned to 440 Hz, a harmonic tone with no inharmonicity and no damping (with harmonic partials) of a pitch of about 441.2 Hz is required to produce about the same aural pitch impression as the A4 of the Steinway D tone with partial 1 tuned to 440 Hz, because of the higher inharmonic partials involved.

    So the difference of OnlyPure effective pitch (OEP) and pitch of partial 1 on A4 is not a quirk, but by definition and intention.
    As i mentioned before and as Fred proposed, this could be handled by calibrating things out relative to partial 1 (as possible with former versions of OnlyPure). The drawback would the be that after calibration the autocorrelation (whole tone) reading of OnlyPure on a harmonic tone would be off the amount of calibration in the other direction, what would be not meaningful at all.

    To avoid too strong beating between instruments with relative high inharmonicity on A4 (Steinway for example) and a harmonic instrument (Oboe of orchestra), a value half between OEP and partial 1/harmonic tone difference may be preferrable. In the former example when OnlyPure pitch is set to 440 Hz, Oboe can have between 440,6 Hz for a lowest overall beating on A4, or 441,2 Hz for the same pitch impression the piano does with OEP (not partial1) set to 440 Hz on A4. Tuning partial 1 of A4 of the piano about a half beat lower than the nominal pitch of the orchestra (Oboe, Violin) is pretty common in the concert circus.

    ------------------------------
    Bernhard Stopper
    Klavierbaumeister
    Tuebingen
    ------------------------------



  • 23.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-01-2017 18:22

    OnlyPure pitch information is not base pitch (first partial) of A4. It is some sort of autocorrelation function of the whole tone, that means an integral pitch impression including higher inharmonic frequencies and damping effects. So what is shown in OnlyPure for the pitch is a value that corresponds to a pitch impression compared with a pure harmonic tone of that pitch value.
    Bernhard Stopper,  12-01-2017 14:52
    The problem with this reasoning is that pitch standard is based on physical measurement, not on psychological "pitch impression." From a practical standpoint, for the past century and more piano tuners have used a reasonably accurate pitch source, and have matched the first partial of A4 (or C5 for those who used C forks) to the source. They have increased the accuracy of the pitch transfer from an aural source by comparing beat rates with F2, again ensuring that it is the first partial of A4 that is tuned to the standard. Furthermore, all electronic tuning aids (with the sole exception of Tunic software) do their best to place the first partial of A precisely at 440 as the default.

    This is the tradition we live in, and orchestras have lived with it all along (to the extent that matching between pianos and orchestras is important - more for some of us than others, and orchestras do their own types of adaptations regardless of what piano technicians do). If matching a Steinway grand at first partial A4 440 means that the orchestra tunes to 441 (if they are that accurate so that you can say within 1 Hz what the average is), that is what they have been doing all along. There is no harm in it.

    Most professional musicians, and many ordinary people with little musical background, have pitch reading devices that are quite accurate. If I were to tune to OnlyPure, I would have musicians and piano tuning colleagues commenting that I always tuned flat, wondering why. The oboist has his device sitting on the stand, as does the concertmaster, in the concert situation. 

    I think it is unwise to choose to be different in this way. I don't think it will reflect well on the software in the long run. I do understand the argument, but I don't see its relevance in the real world. And I don't see the relevance of the argument that if OnlyPure were to offset to produce 1st partial A4 at 440, that would make the software wrong when tuning a tone with little to no inharmonicity. It's piano tuning software, isn't it? it is meant for inharmonicity.

    ------------------------------
    Fred Sturm
    University of New Mexico
    fssturm@unm.edu
    http://fredsturm.net
    http://www.artoftuning.com
    "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
    ------------------------------



  • 24.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-01-2017 18:58

    Fred,

     

    I have followed this discussion some, and had thought about responding to Bernhard's post.  I'm glad I didn't – your response is very well stated (as usual), and I hope he takes it as intended.  It is very valuable advice that will remove an obstacle to having people buy and use his software.

     

    Don Mannino

     






  • 25.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-01-2017 20:20
    To add to Mr Chernobieff's comment; Thanks Mr Sturm. As mentioned earlier in this thread I too am a recent pitchlab pro owner. Yesterday I used it's tone generator when I chipped the S&S model M I've been stringing and it was really nice not to have to set up the external speaker for the accutuner.


    ------------------------------
    Karl Roeder
    Pompano Beach FL
    ------------------------------



  • 26.  RE: OnlyPure calibration

    Posted 12-01-2017 21:48
    This is very interesting...

    There is Bernhard, Only Pure, maybe Virgil, maybe Kent to some degree, if I am reading into his excellent articles without being totally lost,  questioning, I think, what the utility of extracting 1st partial A 440 as an absolute benchmark is, when the perception created by the totality of the A4 tone may be registering, either aurally or with an appropriate algorithm, as a different value.

    Then there is Fred, Don, Jason, and probably many or most tuners, saying that an extracted portion of the tone, disregarding the effect of the whole on the perception of the complete sound, is a valid benchmark. Saying that a model of the simplified tone, is more important than the perception of the whole tone, mainly because its easier to measure, and easier to fit into a simplified model of the tone.

    One values the complete tone, attempting to allow a messier, more complicated reality to define what the perceived pitch is, the other, valuing a simplified model of the tone, because its easier and convenient to assume that the simplified model reflects the total sound..  .

    Fred< orchestras do their own types of adaptations regardless of what piano technicians do.

    If read him correctly, Fred does not present the customary orchestral tuner approach as having an absolute meaning. Rather, his comments  suggest, that since the perception of the whole piano tone is so complex, no one without a device measuring select simplified signals of the complex tone, really can tell the difference, and adjusts aurally as necessary, no matter what the tuner thinks he did.

    There is an level of unavoidable uncertainty here that I find quite comforting.

    ------------------------------
    Jim Ialeggio
    grandpianosolutions.com
    Shirley, MA
    978 425-9026
    ------------------------------



  • 27.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-01-2017 22:55
    Legend has it that the great Morris Schnapper was tuning at Carnegie Hall while Eugene Ormandy was onstage. Maestro Ormandy remarked that the piano was sharp " 441 maybe even 442" Mr. Schnapper took out his tuning fork, struck it on his knee, placed it on the bridge, looked the Maestro in the eye and said: " Okay Maestro; Start counting." The legend reports that The Maestro just smiled then walked away.

    ------------------------------
    Karl Roeder
    Pompano Beach FL
    ------------------------------



  • 28.  RE: OnlyPure calibration

    Posted 12-01-2017 22:55

    There is an level of unavoidable uncertainty here that I find quite comforting.
    Jim Ialeggio,  12-01-2017 21:47
    I like the way you think...😏😉

    ------------------------------
    "That Tuning Guy"
    Scott Kerns
    www.thattuningguy.com
    Tunic OnlyPure & TuneLab user
    ------------------------------



  • 29.  RE: OnlyPure calibration

    Posted 12-01-2017 23:25
    I guess for me, having used the software for several years now, I just accepted that I can't use OnlyPure as a measurement of pitch. I use TuneLab for that. It seems that nowadays most people who use an ETA have at least two of them anyway. Quite often now I do what Kent does and have two of mine set up at the same time while I'm tuning, mainly going by what OnlyPure calculates but TuneLab can read the lower and higher notes better so it's helpful in those areas. I have settings I use with TuneLab that can mimic OnlyPure. Many times, in the past, when I'd finish a tuning, I'd check A with OnlyPure and it was usually off just a little, but then checking with TuneLab it was on. And then again sometimes the pitch had drifted a little but not enough to tune the piano again. Also, since I use the Android version that has the "Calibrate" function on it I hadn't thought about this subject before!

    ------------------------------
    "That Tuning Guy"
    Scott Kerns
    www.thattuningguy.com
    Tunic OnlyPure & TuneLab user
    ------------------------------



  • 30.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-02-2017 00:21
    My thoughts are: A4 should end up with the first partial at exactly 440. When the entire piano is tuned, including the unison of A4. The reason this was established in the first place was to set a scientific standard by which different pitch levels could be judged. Note I didn't say different stretches. 

    To disregard this and say, yea, but A4 at 441 sounds better with this tuning, is to defeat the purpose for which the standard was set in the first place. If that's the case, then shift your tuning down to match. Don't ruin the one note that needs to be consistent at a designated pitch level.

    Stratching the piano different amounts is a whole other story. Tuning A4 to end up at a precise pitch level should be one of your goals in every tuning. People judge a piano tuning by several things, mostly by the unisons. But remember that musicians will measure a piano at A4. One of my first mistakes in the field was to not offset for A4, and it ended up at + 2.1 cents or so. I wasn't called back to that piano, because the owner was a professional musician, and she didn't like A4 at 440.5.

    Where A4 ends up is important, at least in my book.

    ------------------------------
    Benjamin Sanchez
    Professional Piano Services
    (805)315-8050
    www.professional-piano-services.com
    BenPianoPro@comcast.net
    ------------------------------



  • 31.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-02-2017 12:12
    In addendum to my previous comment, I think it's important to KWYADAWYADI (Know what you are doing and why you are doing it), in all aspects of life, in this case setting A4.

    If you decide to set A4 randomly, KWYADAWYADI, from a historical, cultural, and scientific standpoint.

    ------------------------------
    Benjamin Sanchez
    Professional Piano Services
    (805)315-8050
    www.professional-piano-services.com
    BenPianoPro@comcast.net
    ------------------------------



  • 32.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-03-2017 09:21
    Benjamin,
    I don’t agree that the exact value of A4 is that important. Your ETD should be able accurately measure A4. At a minimum it should function as an accurate tuning fork. But...

    I tune many concert and recording pianos. I want them all to always be 2-3 cents sharp. I have NEVER had a complaint about this pitch level. The most important aspect of performance tuning is stability. By being a little sharp you never have to completely retune before a performance.

    Sent from my iPad
    CarlPianoTech.com




  • 33.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-04-2017 18:08
    I agree with Carl, that precise 440 is very rarely all that important, and that being a hair sharp is better than being flat as a general principle (although I will also often allow a concert instrument to drift 1 - 2¢ flat before adjusting pitch - stability trumps everything else).

    I think the OnlyPure issue was stated in a way that has caused some confusion. For a Steinway D, if A4 is tuned by OnlyPure, its first partial will measure 5¢ flat, meaning it is 438.8 or so. This will definitely cause people's eyebrows to go up, and will not be good for the tuner's reputation.

    Steinway has tended to advise keeping its C & A instruments at 441, which many people do. In my town, I have had feedback about this, thanking me for tuning 440, as "the other guy always tunes it sharp." Maybe it was more like 441.5, I don't know. In any case, it is unwise to believe that, since nobody has complained, they haven't noticed. 1-2¢, I don't think anybody notices. It is beneath the threshold of most cheap tuning devices (though Pitchlab will catch it).

    ------------------------------
    Fred Sturm
    University of New Mexico
    fssturm@unm.edu
    http://fredsturm.net
    http://www.artoftuning.com
    "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
    ------------------------------



  • 34.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-04-2017 20:03
    If you want an accurate A440 go to NIST at two minutes after the hour.
    http://tf.nist.gov/stations/iform.html

    ------------------------------
    Larry Messerly, RPT
    Bringing Harmony to Homes
    www.lacrossepianotuning.com
    ljmesserly@gmail.com
    928-899-7292
    ------------------------------



  • 35.  RE: OnlyPure calibration

    Posted 12-06-2017 08:37
    Carl-Johan Forss, in his tuning book, teaches using F3 to test A4 to the tuning fork. This will result is A4 being 1-2 cents flat of 440 Hz, since the fork gives an exact 880Hz at its second partial.
    This method is taught in Japan, and perhaps in Canada. How common is it in Europe? Is the F2-A4 test unique to the US?
    Perhaps Bernhard Stopper will tell us his method for setting pitch to a tuning fork.

    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
    ------------------------------



  • 36.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-06-2017 14:16
    I have never heard of using F3 to test A4 with a tuning fork. But then again most of my training has been in the US rather than Canada.

    ------------------------------
    Peter Stevenson RPT
    P.S. Piano Service
    Prince George BC
    250-562-5358
    ps@pspianos.com
    ------------------------------



  • 37.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-06-2017 15:34
    Sometimes I use F2 to check A4, but most of the time I end up using B1. Its just easier for me with my current fork. My last fork was easier to hear at F2.

    ------------------------------
    Benjamin Sanchez
    Professional Piano Services
    (805)315-8050
    www.professional-piano-services.com
    BenPianoPro@comcast.net
    ------------------------------



  • 38.  RE: OnlyPure calibration

    Posted 12-06-2017 17:44
    I mention this, in the context of Bernhard's comments on "what is A440, really" because it seems there may be a European tradition of functionally setting pitch at 880Hz, or at the second partial of a tuning fork.
    Susan Kline, who contributes to this list, is an advocate of F3-tuning fork for A, and she is also a devoted student of Ted Sambell, leading me to wonder if the F3-tuning fork technique came with Ted from Britain. Hopefully Susan can tell us.
    I recall reading that the use of F2-tuning fork was introduced by Al Sanderson. If so, it is not a very old technique. Perhaps someone can remember if that is so.
    Overall, we can see that the degree of accuracy in setting pitch has been significantly sharpened by digital technology. It is the world we live in, but we need to remember that the world of musical reality is not nearly so precise as a momentary encounter between a single string and a digital screen.

    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
    ------------------------------



  • 39.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-06-2017 17:52
    Soooo...when the PTG test is being scored, what exactly is the ETD actually reading, in order to decide whether we are within 1 cent of A440? I'm curious.

    Pwg

    ------------------------------
    Peter Grey
    Stratham NH
    603-686-2395
    pianodoctor57@gmail.com
    ------------------------------



  • 40.  RE: OnlyPure calibration

    Posted 12-06-2017 18:25
    440Hz only.

    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
    ------------------------------



  • 41.  RE: OnlyPure calibration

    Posted 12-07-2017 05:32
    Hi Ed,

    F3-A4 is the "old standard" here in Europe. As you mentioned correctly, this sets A4 to 880 Hz on the second partial. (It is very common to find old signatures in pianos with A=880 Hz). A slight correction: Tuning the second partial of A4 to 880 Hz does not make the piano only 1-2 cents flat on the first partial, but around 0,5-0,7 Hz (about 2-3 cts at A4) on a typical piano scale, a value that is pretty common as i mentioned earlier. Thanks to Fred for his excellent description of the current pitch standard (which i am aware of..), often provoking situations as the one described by Karl Roeder between Schnapper and Ormandy.

    ------------------------------
    Bernhard Stopper
    Klavierbaumeister
    Tuebingen
    ------------------------------



  • 42.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-07-2017 16:43
    In the 19th century, it was common to refer to the number of vibrations, meaning "single vibrations" - motions of the string in one direction or the other, to and fro being counted separately. Hence, the diapason normal of 435 adopted in France in 1859 was expressed as 870 vibrations in the official wording of the law (as quoted in Montal's Art of Tuning). It was only later that the convention was changed to "double vibrations" or cycles (motions back AND forth), which came to be known as Hertz (Hz). I suspect this is the source of the 880 seen in old pianos - they were using the old tradition.

    In the US as in Great Britain, the C fork was used as a pitch reference far more commonly than A until fairly recently, and though the fork was actually C5, the majority of tuners used it to tune C4 directly. This would result is a pitch slightly flat from the one advertised. But this is not nearly as important as it might seem, as the forks themselves were rarely all that accurate, as we learned in PTG when we began giving the current design of tuning test. Initially, we had an offset for "fork error," which was often pretty big. In more recent years, the test was changed to require 440, and lay responsibility on the examinee for having an accurate source. 

    At this point, with the proliferation of modern electronics, anybody can read pitch accurately (or thinks so - it depends on the device or software whether or not that is actually true). This puts our work under a magnifying glass, so we are wise to just be accurate. At least that is my attitude. I know full well it doesn't matter whether a piano is 439, 440, 441, or 442 for almost any practical purpose (and in most cases, even that tight a standard isn't needed), but I also know that my reputation is always on the line.

    ------------------------------
    Fred Sturm
    University of New Mexico
    fssturm@unm.edu
    http://fredsturm.net
    http://www.artoftuning.com
    "We either make ourselves happy or miserable. The amount of work is the same." - Carlos Casteneda
    ------------------------------



  • 43.  RE: OnlyPure calibration

    Posted 12-02-2017 17:17
    I was told a story, perhaps apocryphal, of an oboist who attached a digital frequency measuring device to her instrument.
    This worked well when she gave the tuning note for the orchestra, but when she insisted on following the digital authority throughout the performance, her tenure was radically shortened.

    ------------------------------
    Ed Sutton
    ed440@me.com
    (980) 254-7413
    ------------------------------



  • 44.  RE: OnlyPure calibration

    Member
    Posted 12-02-2017 19:08
    Well here's some interesting data. 
    Bernhard is using some fuzzy language ("It rather interprets some sort of "OnlyPure Effective Pitch" (OEP) by a proprietary autocorrelation function, where OEP deviates from partial 1 pitch with increasing nonlinearity (inharmonicity, damping)", "It is some sort of autocorrelation function of the whole tone, that means an integral pitch impression including higher inharmonic frequencies and damping effects. So what is shown in OnlyPure for the pitch is a value that corresponds to a pitch impression compared with a pure harmonic tone of that pitch value") to describe a phenomenon that is however clearly measurable. The string has partials that can be measured. The industry standard is A4(1)=440. Because of inharmonicity, A4(2) is always greater than 880 and A4(3) greater than 1320 by some factor.
    TuneLab is based on calculating that factor by extrapolating from six measurements, and then each note is tuned by matching a single partial to a specified frequency. Most tuning software is based on the same basic understanding of the matching of partials that are inharmonic.

    SPECULATION FOLLOWS!
    I thought, hmm, let's look at the 3rd partial, because that's the one that gets matched by the perfect twelfth ...  (On my piano tuned with OnlyPure, A4(3) is 1323.9, which is fatter than the perfect harmonic 1320) ... and since Bernhard is putting emphasis on perfect harmonic relationships, what if we take 1323.9 and treat it without any inharmonicity - it's the 3rd partial of 441.3 if there were no inharmonicity! Pretty close to what gets displayed on the OP screen. So this may suggest how OnlyPure is working behind the fuzzy logic. It may be looking at the third partial as the heart of the tone, and extrapolating downward. (However, E6(1) measures at 1326, which is fatter than 1323.9, and the twelfth sounds lovely, so it's certainly not just matching one pair of frequencies.)

    ANYWAY...
    Whether or not that speculation is correct, the fact is that this community thinks in terms of measurable partials, and we also know that there's a lot of fuzziness in how the whole sounds come together, so we tolerate and sometimes wholeheartedly embrace the fuzzy.

    The software is listening and making its interpretations of what it hears. And it places a number on the screen. This number is meant to represent something. It sounds like Bernhard is suggesting this number is what the attendant oboist ought to be using to match this piano. If so, the number should be labeled as such. And I can't think of ANY reason why the software could not be trained to display "440.0" when the first partial is measurable as such. OnlyPure should be able to tune A=440 (or whetever we wish it to be) before it starts doing the fuzzy magic.

    "THIS MAKES NO SENSE"
    Bernhard said: "The drawback by calibrating the difference of OEP and partial 1 caused by nonlinearity is that with a harmonic signal, OnlyPure would read a difference between OEP and partial 1 then, which makes no sense and is the reason why the calibration has been pulled off." As a result, OnlyPure now reads a tone that we have pre-determined to be 440, and displays it as (for example) 440.9, and THIS "makes no sense" either. And if I just start OnlyPure in a state where its display says "440.0", and tune that note, it measures 439.1, and THIS "makes no sense" either.

    The software has intelligence. The consumer wants to know the frequency of the first partial of A4. The software cannot deliver it? That makes no sense.

    | || ||| || ||| || ||| || ||| || ||| || ||| || |||
    jason's cell 425 830 1561

    On Sat, Dec 2, 2017 at 2:16 PM, Ed Sutton via Piano Technicians Guild






  • 45.  RE: OnlyPure calibration

    Member
    Posted 12-03-2017 13:49
    Interaction between Gmail and my.ptg.org sometimes messes with the formatting of my message. I want to repost the bottom line of my last post.

    "THIS MAKES NO SENSE"
    Bernhard said: "The drawback by calibrating the difference of OEP and partial 1 caused by nonlinearity is that with a harmonic signal, OnlyPure would read a difference between OEP and partial 1 then, which makes no sense and is the reason why the calibration has been pulled off." As a result, OnlyPure now reads a tone that we have pre-determined to be 440, and displays it as (for example) 440.9, and THIS "makes no sense" either. And if I just start OnlyPure in a state where its display says "440.0", and tune that note, it measures 439.1, and THIS "makes no sense" either.
     
    The software has intelligence. The consumer wants to know the frequency of the first partial of A4. The software cannot deliver it? That makes no sense.


    ------------------------------
    Jason Kanter
    Bellevue WA
    425-830-1561
    ------------------------------



  • 46.  RE: OnlyPure calibration

    Posted 12-07-2017 07:46
    Why not set A3 to an A4 fork and then tune A4 to A3?
    Then A4's pitch would be considered as the 2nd partial of A3?
    That is, if you are unwilling to use the 1st partial of A4 against a fork.

    Isn't there a standard, meaning a measurable constant? Without that no two pianos would be in sync.
    Or should we revise the saying: "Close only counts in horseshoes, hand grenades and A4."

    ------------------------------
    Regards,

    Jon Page
    ------------------------------



  • 47.  RE: OnlyPure calibration

    Registered Piano Technician
    Posted 12-07-2017 08:55
    Jon wrote:
     "Close only counts in horseshoes, hand grenades and A4."

    …and dancing!

    Alan

    ------------------------------
    Alan Eder, RPT
    Herb Alpert School of Music
    California Institute of the Arts
    Valencia, CA
    661.904.6483
    ------------------------------