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I am interested in understanding the thoughts behind open unison tuning forgoing use of the muting strip. Would such a tuning yield any difference in tone and, if so, how might this difference be characterized tonally? What are the supposed advantages or disadvantages? If there are advantages, why isn't this technique used by more technicians? Finally, will open unison tuning make any difference in the stability of the tuning? Thx.

Greetings,'
The advantage, when tuning aurally, of tuning sequential notes from open unisons is that rather than the interval being set by one of a trichord's three options(strings), the open unison provides the "note" as a resultant of the three strings being blended. This rarely makes any difference, but at times the "whole-tone" sound of the unison (to quote Virgil Smith RPT), is not quite the same pitch as any one of the individual strings. The blending of a unison tends to have a flattening effect, if it does anything. There are scales that require such a compromise that a more informed choice of octave width can be made from the full tri-chord rather than one of the three strings.

The stability of the tuning is more dependent on the skill of the tech than the style of tuning. It is rare that a novice tuner can leave stable, clear, unisons, so there may be more stability associated with tuners that have more experience and tune this way. One has to have full faith in their unison tuning to use unisons for setting a proper temperament, but if a rolling unison is acceptable, there is little chance of the temperament being accurate.

I use open unisons when tuning because in performance settings, they are going to have to be clear anyway, and it is faster to use one mute than muck around with temperament strips.
Regards,


,

From what I’ve read there are some technicians who argue that using mute strips creates small changes in the actual tuning leading to less precision. I’ve read and watched a video on tuning only muting one string of the trichord which was interesting, but I’ve not heard too much about not using any mutes at all.

There may be more rationale behind it however.

in terms of the science of physics - No difference . There is no difference HOW you will create your unison. You can pinch a string, you can do it's with a narrowly directed air flow on it's although this is an inadequate method .
Conclusion: it is not important as method the string is oscillatingly moving in, the most important thing is a mark the digital tuner .

Not correct.
It has been established scientifically that the pitch of of a multi-string unison will be different with all the strings sounding than with a single string. This is because of a phenomenon they call "bridge coupling". The same principle is present in adjacent pendulums swinging from the same pivot.

Or, you can just listen and decide for yourself:
1) mute two notes an octave apart in the low tenor (say, for example, F-33 and F-45) so that only one string of each note will sound.
2) Tune as good of an octave to your satisfaction. Doesn't matter if it's 4:2; 6:3 or 2:1-- just tune it until it sounds good to you.
3) now move the mute on the lower note to expose an additional string (of course, it will be the center string whichever side you started on)
4) Tune the center string to the first string you tuned. Make it as good of a unison as you can.
5) Now strike the octave again. You will notice a beat that wasn't present there before. The octave with the two strings sounding will be different from the octave with one string sounding.
6) Re-mute the center string and listen to the octave: Voila! It's back to clean!
7) you can move the mute back and forth as long as you want... With one string sounding, you'll have a clean octave but with two strings sounding in perfect unison there will be a beat in the octave.

That's why it is good to develop the skill of "cracking the unison". That's very slightly opening the unison with one string and then tuning the other string so that you have slightly changed the pitch of the 2-string unison to be beatless with the octave.

This only really matters on larger pianos -- either 5'6" grands or perhaps very tall professional uprights. On smaller pianos, the phenomenon can be detected but with the shorter strings the effect is negligible. I used to tune my home piano (Baldwin Hamilton 243 studio) that way but stopped because the difference was marginal. But it's really noticeable on a good grand.

Since I started doing this over 20 years ago, my tunings have been more solid and "locked-in" from a musical standpoint. Previously, even though other people thought my tunings were OK, I was never really satisfied with them. Now I am.
This is a capability that electronic devices have yet to develop, BTW.

???

Whenever anyone comes up with some fancy name for a method of tuning, you can pretty much bet the name and the method are useless.

I'm not clear about whether we might be talking of two different things here. The O.P. talks of "forgoing the use of the muting strip" and "open unison tunings". Does that mean tuning with no mutes at all, or tuning using individual mutes INSTEAD of a muting strip?

I take "open unison" tuning, to be tuning without any muting at all (as might be done in a quick-pass large pitch raise).

I take "unisons as you go" tuning, to be tuning with individual mutes instead of a muting strip, completing each unison as you go, before moving on to the next note. For both the temperament, and the entire piano.

I'm 99.9% sure the OP is talking about just using 1 or 2 rubber (or whatever) mutes, each unison tuned fully before proceeding to the next note, as Keith described. IOW "unisons as you go" or "UAYG".

Pwg

I assumed the OP meant tuning the unisons without the use of mutes. Maybe he should clarify.

Not sure exactly what you are referring to in this thread.

Is it not correct that in order to talk about phenomena we have to have terminology?

In my post in particular, I provided an actual experiment that anyone who can tune and has access to a piano with at least medium-long strings can try.
Is this not the scientific method -- to have experiments that allow anyone to verify whether an idea is valid or not?
Did you try the experiment (or have you done this in the past)?

There are many high-reputation technicians that have found these techniques to be the opposite of useless.

Again, I'd be glad to know the nature of the concern behind your comment. For myself, I've only been tuning for 55 years, so I'm still learning and still interested in new concepts.

Actually it's both. Yes, it's "Unisons As You Go" but in order to account for the pitch differential of coupled unison strings vs. single strings, it may be necessary to "crack the unison" (a term I've been taught, but I'm open to something better) which is, indeed, mute-less unison tuning.

Yes. I have quite often observed this. I tune unisons-as-you go (much more the general trend in the UK than in the USA) and generally use an ETD, formerly Tunelab, now giving an extended and enjoyable trial to Easy Piano Tuner. I pride myself on clean unisons. I have quite often seen that when I tune the unison clean, the ETD shows a slight flattening, after the reading was 'correct' with the single string.

Dr Capleton in his monumental book on Tuning, reviewed in the Journal a few years ago, approaches almost philosophical levels in his discussion of these coupling effects.

Keith,

55 years? You're just a punk kid upstart. What do you know? 🤣😆😅😂😉😨🤡

All in jest -

Pwg

This question of tuning unisons as you go vs. using temperament strips has been discussed many times on this forum - sometimes with an excessive and, in my view, uncalled for rancor. There are some very fine technicians who strip mute the entire piano and there are others who do not. Both approaches have advantages and disadvantages.

I too am a newbie - only been doing this for about 40 years - strip muted the entire piano for about 10 or 15 years. After that I strip muted only the temperament area and tuned the rest unisons as you go - this was tuning aurally. For the last 3 or 4 years I've been using an ETD and no longer use a strip mute. Using a strip mute for the temperament area had the advantage of allowing tweaking of intervals without having to tune all the unisons again. Once the strip mute was removed and unisons tuned the temperament could be checked again for accuracy before proceeding. I find the strip mute to be unnecessary when tuning with an ETD. But, again, there are some very good technicians who strip mute even when tuning electronically.

Let me toss out something:

Consider the aural approach to setting A4 from a fork. At one time, it was common to sound the fork, then simply tune one string of A4 - same as how most of us approach unisons... functional, "beatless", perfect - though some may have noticed a tiny bit of 'width' or wiggle room on just what made a functional unison.

As tolerances tightened (possibly in response to increasing precision from ETDs?) it was determined that the old method didn't always produce precise results. Strategies were implemented by using check notes (F2 most often) to compare between the fork and the string to make sure the tuned string REALLY matched the fork.

All well and good! However, how many technicians use check notes to make sure each string of a unison REALLY matches the others in the same way the check notes are used to match the fork??

All of this to say that after very careful study and testing at the limits of what I could achieve, I found no repeatable, predictable coupling effect happening on the pianos I had available. Sometimes there was flattening, sometimes sharpening, often no difference. What I did discover early on, was that my functionally pure unisons - really clean - really weren't... Also, I found that slight movement of one string often had an influence on the pitch of an already tuned string, skewing the results of the unison pitch.

Again, this was way at the edge of what I could measure, repeat and produce - so not a big effect. Your mileage may vary!

Ron Koval

I am just a toddler at 44 years myself.

Once I learned and proved to myself the "Weinrich effect" I set out to see if I could harness it to my advantage. This was largely in response to Virgil Smith's lack of thorough explanation as to precisely what he was listening to when he was "satisfied" with a unison. Since he openly acknowledged that he was NOT tuning all three strings EXACTLY to the same frequency, the question was: just what was he doing with these three strings and what was he listening for?

I found that I could consciously influence the pitch of the first string by the way I tuned the second string, and that I could further influence that pair by how I tuned the 3rd string. I could influence it up, down, or stay the same as I tuned it essentially harnessing the power of the coupling as I want it to go. At the same time I noticed that I could simultaneously affect the sustain of a note (in a high % of cases) by carefully manipulating the middle string only, finding a sweet spot that sounds best.

It has been proven that absolute dead on perfect same frequency unisons actually do not sound as good as unisons "tempered" slightly. Some will argue this till the cows come home, but there are plenty of good tuners who privately understand and employ this technique regularly, some of whom are on this forum.

Of course, I too am open to suggestions from the adults here.

Pwg

Learning a lot from the terrific discussion in this thread. My understanding of open unison tuning is exactly as Keith describes, which is unisons as you go, but with the need to crack the unisons without a strip mute.

Well, I got an early start. First paying customer at age 14. My dad would drop me off at one customer, go tune another, come back and I'd just be finishing up. He could check over and make corrections as occasionally necessary.

Greetings,
hmm, "as good". is where I run into trouble. It may depend on context, but the totally clear unison seems to appeal to jazz players, perhaps because of the complexity they seem to find irresistible . The perfectly dead-on unison will usually exhibit less sustain than one with enough phase difference to physically create a more solid termination at the bridge. However, the dead-on strings still have dissipated the same amount of energy, just in a shorter amount of time and what is deadness to one is perhaps clarity to another. I have customers that notice my tuning sounds "better" a day after I did it, and others that find something in an extremely fresh tuning worth paying for every day, (that is in the recording studios). A piano with this sort of unison has its place, so I am inclined to begin there. Seems that the .1 or .2 cents or so that it takes to offset phasing distractions in the unison will come of its own in the first day or so of use. This can be due to board movement, I think, since the deviation from where I left them seems to be fairly consistent, i.e. all the right hand strings being the same amount "off" from the center, and in the same direction. From the practical perspective, the closer to exact I begin with, the longer it will take before it calls attention to itself, so in the interest of durable tuning, I start them as close to dead-on as I can get them. Above the fifth octave, that can often become subjective, but in the lower scale, I want things to be very, very, still.
Regards,