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I have had some success by asking students to listen to what happens as they move the pitch well above to well below the unison. It seems easier for them to grasp a beat rate that is overtly changing rather than focussing on a beat rate that is just sitting there. Once they recognize that the rate slows, then increases, and they want to find the middle point, they have a target. It is, at first, a zone. Often anything slower than a beat per second is heard as pure, but as they continually pass through purity on their way to the extremes, their hearing awareness increases and they gradually can begin to hunt around in that spot where the beat rate stops changing.

After that, a few pointers about the difference between lack of beats and lack of meowing will help them tighten their control and standards. Some people simply do not hear beating, but most do, and once they recognize what is happening, and where it is, they can begin judging their hammer technique with some sense of measurement. At some point, they may recognize an uneven string mating as it tries to masquerade as an out of tune unison, and with enough years of futile fussing, will learn to ignore the false beat's quicksand attempts to steal another 30 seconds of our tuning time.

Regards,

Ed, Mark,

The problem is (when possible : friendly pins) that the phasing between strings is to be installed at the bottom of the pin, it is not enough to "polish the phase" with the upper part position, but it have to be sourced where the pin is "really set" , I mean at its strongest grip, at the bottom.

So managing the so very small differences (That I seem to hear more as pitch focus on the partials more than fundamental) so the unison will tend to stay that way, the reading of the bottom of the pin and its manipulation must be very precise.

I personally found always the "smiley" (coupling between external strings, center one more on the fundamental) to arise naturally sometime in seconds if it was not installed initially.

When experimenting with that open unison where every string is tending high of the next (thick tone little attack) it happens very often that the shape goes to the smiley shape fast.

It happens as well with "dead on" sometime 30 seconds playing and the "smiley" is installed.

Strings tend to couple, physically, but there will be one always that do not agree fully.

I know in any case what orientation my string is tuned, dead on, high, low.

Plucking allow to make the analysis easily, and with an ETD even better, in the 0.2 0.4 cts range. What is fun is that thefundamental stay the same, but the spectra of the strings tuned high is emphasing to the 2nd 3d, etc partials. I believe that in that case the fundamental couple physically at the bridge (so both strings have the same) but the phase allow the partials to be present a hair high or simply ùmor present, on the strings tuned "high".
Regards.

Of course I was not talking of extreme changes in humidity, and of course false beats and difficult unisons are in the way of the perfect realisation. But is it seem to be a simple physical effect, it can be put any time, while eventually corrected if some moaning is still there and must be hidden.

Regards

If I compare with my ears, smiley : nicely focused, clear attack, quiet and projecting well.

"Viennese" style, the attack is highly rounded, delayed, the initial imbalance allow for a lively but thick tone, I believe the coupling moves from right middle to left middle in time. Moaning is not so easy to avoid. the amount of sharpening varies from note to note, due to the possibilities offered by the piano. I doubt the stability is really long term.
but it is fun, and you can regulate the amount of percussion somehow (on some pianos).

In both cases the stress on the pin must be similar from string to string (same amount of give up and down (1/3 2/3 for me)
Proof that the setting is similar ; the lever can be moved somewhat vigorously, then the NSL put back in place and with some "massaging" that way, the strong grip from the bottom finally raise in the pin, and the handle of the tuning lever can be slapped without much effect on tone.

I dont know how to obtain a tighter setting.

The difficulty when trying different "styles" is to be able to make the difference between meowing and oscillations of phase.

It is better to have a small hammer file/string hook at hand when doing so, as the smallest unevenness in mating is creating unstable phase shifts.

G. Weinreich seem to state that the after-sound happens when the wire have switched to horizontal vibration (grand piano).

I have seen some experiments done on phase on a grand piano, but was not advanced enough to master the different ways for unison and ask for comparison.
ALso the rare videos I have seen do not give the time stamp, so we dont know the force of the sound, the pitch of the note and the exact moment the video finish. The high speed cameras may not be able to record very long. Anyone have a clue about that ?

WIth motion analysis it seem to be easier to see the exact motion at the bridge and how is the phase orientation. (installing the "mikes" is not that easy, but their reading probably can be calibrated to correct orientation recording)

Again an interview of Stefan Knüpfer , the head Steinway technician in Wien.

http://www.welt.de/kultur/kino/article9465678/Bei-Horowitz-muss-der-Fluegel-von-selbst-spielen.html

Translate with Google , it may be enough to get most of the sense.

The pic seem to show a filed hammer with the strike slightly deported toward the back (reduce impact hardness when hammer is less thick) possibly just the pic...

Ed, you may want to consider writing a comprehensive article about unison tuning for the Journal. Ed Sutton asked around for that some years ago but I don't think anyone ever came up with anything. I told him that I had a one word answer for that: Beatless! However, we all know that there is more to it than that. You seem to have a wide perspective on it, the knowledge gained from some excellent mentors, your own professional experience and knowledge of both aural and ETD tuning.

Oscillations are not beats, I think. What is said is about tone particularities because of the tuning, but it addresses the tone evolving in time, and it is clear that different pianos allow different types of tone envelope as for the pianist and for the music played the tone can be more or less concentrated , more or less "enlarged". Better do it for the pianist , not expecting him to do so for us.

A real analysis with phase and output power analysis could help to expand on G. Weinreigh thesis.
I have samples of 2 different "styles" unison on the same piano, on the same notes, I will try to make a graphic analysis so to see how relates what I hear and what is graphed.

Let's say/imagine some tuners are not "chasing for beats" but they are "building the tone" ,
Their listening mode is not the same and they can project their ear so to listen more or less in the piano.

Depending of what they have in the ear as a "beautiful piano tone" they will finish with slightly different unison.

(BTW it is a neat way to keep the ear from being annoyed by the tone) probably a minimum experience is needed to be sure not to get caught in a partial listening mode.

ALso depending of the sequence used and the method, the result can tend toward different shapes.
I volontarly look for the phase so I do not try to make my strings couples "dead", and the bottom of my pin is prepped to anticipate future evolving. Some shapes evolve by being more "open" without any beat as coupling is strong and tend to stay put, energy wise.
Not all shapes resist the same to seasonal changes.

Bill,
Thanks for the encouragement! I do find unisons the most difficult part of tuning.

My work with string termination conditions has shown that most pianos suffer less than ideal string terminations for tonal clarity. When the pivot termination and stiffness biasing of the strings and bridges is aligned vertically-more pure unisons are possible. Most pianos have some slow and/or weak warbles to every string. When the hammer/string phase is coherent and the unisons well tuned the warbles are reduced.

I don't get the "style" system of unison tuning, I just try to nail them down solidly. All else sounds "de-tuned".

"Viennese type" - D4


"smiley type" same note D4 : sorry for the typo above those are D4 both


I am talking at the end

The shape is definitively different, thicker from the start with the "viennese" type. more sustained but more percussive and clearer with the "smiley".

As said Stefan in the paper, "the German want all the tone immediately, it is there, it is gone" . The smiley type last longer but is thinner somehow.

Here another note the thick body seem to be clearly apparent


Smiley style but hammer mating create slight impurities :

Would it not be clearer to post the actual sound files so that we could judge the comparison of the difference? To me, a unison is defined as two or more strings speaking at the same frequency, not either slightly sharp or flat of the original reference point.

Looking at the graphs I don't really see the point, when they are not taken from the same note. Surely in order to demonstrate the difference one should record the same note on the same instrument after altering the tuning.

Hello, I have to edit - I did the record for a friend , and did not edit all the comments

Those are the same note D4 for the 2first graphs(I made a typo in the legend)

here is a short sample


mp3 viennese unison

Those are recorded on a not too small vertical, it will be better to do so on a grand of course, but I had some time in the shop and that piano was there.

The 2 first graphs series are from the same note.

When listening indeed the "thicker" behavior of the tone is clearer and the graph better understood.

There is a strong phase opposition at the start of the sound with that shape, (my guess) so much noise is absorbed and what remain is a thick tone.

BTW a part of the noise is due by the licking motion of the hammer that does not grip on the steel wire but slips on it a little. I had interesting results by making the underside of the string "adhesive" with some rosin.

Regards

here is that B3 from "Viennese" (plucked strings at the beginning) to "smiley".
It is somehow long as I explain how the pin tighten at the same time.
It is also less easy on a vertical piano to make those fine variations.

B3 from Viennese to Smiley

The sound quality is from a camera (Canon EOS something) just laid on the piano on the bass side.initially it is a video.

The interesting thing is to watch in an editing software as Audacity, that show in real time the power vs time graph (with whatever enlargment you want.
ANother one shows the spectra in real time , SPEAR (free software) as a flag with horizontal stripes. It should be interesting too.

The phase variations can be seen I suppose it looks the same as a beat but it is not. I rarely leave the tone really long enough until extinction, but at last until the end of the thick tone.

Sometime the tone inflates after an initial thick tone, and that make that lively tone. WIth Viennese it is thick and quieter, more linear.

The Viennese type tend to act as an eraser for the non quietened first moment of noise, and hide much extraneous noises leaving only tone with much energy during the thick part of tone. then the extinxion curve is stepper than with the other types.

That is the best I could describe it

With a possibility that that perception is just due to a different balance of partials, hence a different level of energy absorption rate.

reminder , the Weinreich article :
https://www.speech.kth.se/music/5_lectures/weinreic/weinreic.html#top

took me quite some time to relate what I perceive and the article. But it begun when I was stressed to be attentive to the tone projection... (and why turning the head allows to hear in a different plane, listening better to the thin part of tone for instance)

Old things :


Fig. 8 Calculated vertical force on the soundboard when driven by two strings with different mistuning ( f). In this example beats occur only when the mistuning is larger than 0.3 Hz, illustrated by the curve for f = 0.64 Hz. For smaller values the strings lock to a common frequency, and the effect of the mistuning is to control the level of the aftersound (cf. the curves for f = 0.22 Hz and 0.06 Hz).Fig. 8 Calculated vertical force on the soundboard when driven by two strings with different "mistuning" ( f). In this example beats occur only when the "mistuning" is larger than 0.3 Hz, illustrated by the curve for f = 0.64 Hz. For smaller values the strings lock to a common frequency, and the effect of the "mistuning" is to control the level of the aftersound (cf. the curves for f = 0.22 Hz and 0.06 Hz).



In fact, it was observed by Kirk in 1959 that a carefully and competently tuned piano had the strings of the trichords tuned slightly differently by an amount that appeared to vary randomly from note to note. This randomness may, however, hide an underlying regularity. If, for example, you take a sheet of paper and tear it, examination of one of the pieces will reveal an irregular and seemingly random rough edge; yet comparison with the other piece will show that one irregularity exactly matches the other. Our hypothesis here is that, in the same way, the seeming "randomness" of the tuning comes from the fact that the skilful tuner was adjusting this quantity to another randomness, namely the randomness of hammer imperfections, in such a way that the result is not random. It would be interesting to test this hypothesis by investigating, for example, whether good tuners are consistent in the "mistuning" of the individual trichords when tuning the same piano over and over again.

Hi, Olek. Are both of these quotations from the "Five Essays..."?

Thanks for posting the sound files and the images. Could you post the pair of sound files for the D4? Then we could listen while looking at the images, and view the wav files in the analysis programs.

Yes Jake from the link above.

the original wav file is too large to be posted, send me an email I will give you the link.

it is not that easy to get graphs that are clean enough.

the force of the playing influence the shape, but it is fun to look at the time/power while listening.

looking at time/spectra (in Spear) show a very vsmall hole at the fundamental level a little after initial stabilization. May be that is what gives that impression of articulation and better projection.

In the video as I am tuning I play in fact too often to have a complete record of a note. I have a few but I tend to speak and explain what I hear,as soon the spectra is thin enough.

I will join my contact at the IRCAM to propose experiments with shapes. May be a student would be interested to work on Weinreich findings and hypothesis and go a little farther.

Regards

Thanks for the post Ed,

May I suggest that you try this technique with your students next. The problem I have seen with the teaching technique that you have mentioned, and which I have used, is that, as you correctly point out, hearing beats is not easy.

This is more true than one may understand. An out-of-tune unison, or more correctly, a unison that can be improved, is not only beating, but beating at all the partials, and at different speeds.

I tell my students, after explaining the theory of the "wha wha wha wha" beating of out-of tune-unisons, that an out-of-tune doesn't beat like "wha wha wha wha", it beats like "wagala wagala wagala wagala", meaning no clear definition. Even "wagala wagala wagala wagala" has more definition than we really hear.

In other words, listening for beating in unisons is pointless, for the purpose of creating a clean unison. Beating within 1hz is just not close enough, especially for DSU technique.

So, I came up with this technique from my own revelation of what a good unison sounds like, or more correctly, how poor my unisons were, when compared to the new "concept" I was shown by my mentor at the time, Dave Renaud, RPT.

My revelation was when Dave listened to my unison and then retuned it and said, "There. That's a good unison." At that point, the sound seemed to burn into my head; I had an "a-ha" moment, so to speak.

From then on, I tried to compare the unisons I was tuning, with the concept of what a good unison sounds like, from my own imagination, from my memory of that one day when Dave tuned a clean unison for me.

That's the problem for beginners; no imagination, no concept, so that approach fails, unless you preface your lesson with "This will take you years to learn."

Well, that's not my style. I want to give students the chance to succeed, now, if I can.

When tuning a piano, we are always comparing; comparing beats to each other, comparing what we hear with what we think it should sound like, etc.

Basically there are only two ways to compare; compare what we hear with what we think it should sound like, using a developed concept that exists inside our head, or compare what we hear from the piano, with something else we hear from the piano. An example of the latter is comparing beat speeds of intervals and making judgements about which speeds need to change.

Similarly, we can let the piano tell us where to improve when tuning unisons. We can compare our tuned unison with what we hear in the piano. In other words, a student using the following technique, doesn't even need a concept of what a good unison sounds like, in order to be able to tune good unisons.

This technique deals with the colour of the unison at a very high level. Almost all my beginner students can get really close unisons using this technique. What's more, they tell me where improvements are needed, by listening to the piano, I don't need to tell them, and they continually move toward better unisons, even after the course is over.

Here is the technique.

1. Tune a bunch of trichord unisons, quickly. About 6 to 8.
2. Listen to each unison and identify the stinkers.
3. Pick a stinker.
4. Using a rubber mute, mute off the left, then listen to the centre and right together, then mute the right string of the unison and listen to the center and left together.
5. Make a judgement; does one pair sound better than the other? Cleaner? More pure?
6. Find the pair that could be improved, and tweak the outside string of that pair until it is improved. Students don't need to know what perfect sounds like, they'll get there at their own speed as long as they keep trying to improve.
7. Now listen to the trichord unison again. Invariably, the unison sounds better. As beginners, they need the reinforcement that they are improving the piano. As their ability to discern where things can sound better, improves, their tunings will improve. Until then, they get to feel competent that they are improving, themselves, and the piano.

Being able to identify where the piano can be improved, determines our skill level as a tuner. Skilled technicians hear where smaller changes can make improvements, where beginners are satisfied with larger windows, or tolerances. It behooves them to tweak all the notes that they can tell could be improved, into their windows of tolerance. For beginners, these windows need to be framed by other things they can hear in the piano not by verbal descriptions from books or other technicians.

Some points to remember when using the "Let the piano tell you" approach to unisons:

This works best if at least the left or right pair are close to pure. If the left pair and the right pair sound the same, the centre may need the tweaking, or all three pairs of strings, the left-center pair, the center-right pair, and the left-right pair, may not be close enough. One can always try tuning each pair individually, to avoid trying to tune a string to two other strings that are not close enough.

A good understanding of NSL and stability is needed, as well as massage and other techniques that allow the student to make the small fine adjustments necessary to get good, clean, pure unisons, and get them to stay there.

If there is difficulty getting a good unison, listen to each string separately. If one string has a beat (false beat) or in any way has some unwanted noise, then the unison will be very difficult to tune clean. The tuner must try to ignore the unwanted sound, or use cancelling techniques to minimize it. The point is, not to get too upset or obsessive over it. Do your best and move on.

Another important aspect to distinguish is the beginner unison verses the concert unison. Some techs in this thread are discussing different colours of unisons. The beginner tuner, and many professional tuners, do not concern themselves with this level of detail. It is not needed for most regular tunings, IMHO. But more importantly, the beginner tuner should concentrate on getting as clean a unison as possible before trying to set consistent unison colours. One tech has mentioned that he just tries to get the unisons dead on, and that the drift will create its own colour.

I hope this helps some beginners. Questions welcomed.

" Some techs in this thread are discussing different colours of unisons. The beginner tuner, and many professional tuners, do not concern themselves with this level of detail. "

Yes I guess we took the thread to a level that is not for beginners, while ED answer was initially for a total beginner.


That said, we where soon more discussing of the way the effect described by G.Weinreigh was influencing the delay of decay and shape of the tone.

This is just unavoidable, what is is the idea that dead on unison exists in the sence of the strings moving the same for more than a few seconds of tone.

As you said the window of tolerance of beginners is really not the same. I recently receive a sound sample of a beginner tuner with much interest in physics of tone, he proudly told me he use the "Viennese way" (in fact it is used by many many tuners )

It was not far from honky tonk, with minimal consistency.

We always know which side of the unison we are, even when dead on the optimum clarity can only be between 2 strings.

That is a way of listening so indeed students better learn that soon - When tuning daily different pianos the "tone" is understood in 3 months +-
As you said, it is not necessary for fast tuning, but who can do the best make a better usual work, with more easiness.

BTW pianists (real pianists) hear well the tone dynamics differences with the "shapes" .

For "colours" it addresse more the amount of focused partials in regard to the amount of fundamental, seem to me

Regards

Very useful to be aware of the different patterns unison are build.
For instance I had to correct a 3weeks old tuning. Tone wise, and some notes where too low a very little.

Knowing how to decode where a strip mute was used, and where standard mute where, you can make the economy of some muting as you know in advance where the beat will appear, and how the tone will stabilize in the end.
There are only 3 possibilities :

couple on one side plus one -
smiley (external coupling) ,
and Viennese type (every string strings ahead of the next)

I find myself plucking more than usually, but then almost no muting necessary.
In all types the fundamental can be reinforced or the partial side of the tone. This is not directly related, even if the smiley is clearer I believe.

I chnaged the smiley unisons of the mediums (strip muted originally)in a rounder Viennese shape, and find the Viennese shape yet in most of the treble notes,(after plate break) because tuned one after one; some needed to be raised a little and it was not that difficult to do so without muting.


I did not thought of that advantage before.

Regards