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I noticed this when auditioning pianos, how much different the sound is from the pianists position than the audience member. The pianist is getting a rather 'unintegrated' sound. Reminds me of when I used to play in the orchestra - never could hear the darn string section practically.

After 10 feet or so it should be a moot point, but I would expect that the piano would have the most variation of sound within that radius.

Thinking about instruments, the sound from brass instruments comes almost entirely from the bell, which can be easily verified. Woodwinds, such as the clarinet, are more complex. The sound comes mostly from the bell, but also strongly from the finger holes. Thats why a fully closed up position (low E say) is very directional from the bell, but an open position (G above middle c) comes mostly from the open holes.

Given it's size, the piano has to be one of the most complex sound sources.

Dan

Well, yes, I know. This tonal dispersion effect is particularly noticeable at the keyboard with some of the shorter and wider pianos in which the low end of the tenor bridge and the top end of the bass bridge are located rather far apart. Playing across the bass/tenor break has sound coming at you from two quite widely separated areas.

This is both a blessing and a curse. A blessing in that this widely dispersed wash of sound it is inherent to the piano (and certain other instruments such as the pipe organ) and is part of what makes it difficult to duplicate electronically. And a curse in that it can make the bass/tenor crossover rather difficult to blend and voice if these two points are too widely separated.

Still, I have assumed (when I’ve thought about it at all) that this effect would diminish with distance. You're thinking not and I haven't a clue just yet. I wonder if any kind of testing has been done to quantify the energy projection capability of the two (point source vs. a dispersed source) at various distances.

Del

Higher frequencies get absorbed faster than lower frequencies. That's how whales and elephants can communicate over such great distances. It's why you hear the thump thump thump of a car stereo when you can't make out anything else.

Well, I haven't thought it through much myself, but I agree that the farther away from the piano you are, the more it approximates a point source, so the sound will tend to integrate better I would think. I confuse myself the more I think of it. The lid will tend to reflect higher frequencies better, so on axis will surely sound very different than off axis. I don't know.

My copy of "The Physics of Musical Instruments" (Springer-Verlag) is at work, but I bet there's a good chance something is in there. I also have access to the Acoustic procedings journal at work, I could see if there is anything there.


BDB. You are correct, but I had thought that in air the attenuation is low enough that it makes little difference. At least I believe that listening to a triangle or oboe (with lots of high harmonics) up close is not that much different than being up in the back row.

Dan

Don't want to open up a new can of worms, but I can't help myself.


How does scale tension affect inhamonicity? Do lower tension pianos have more inhamonicity and does it even matter that much?

You can only change tension in two ways; by changing the length of the string or by changing the diameter of the wire. (Well, you could also change the mass density of the wire but that is not really practical in the real world.) Both of these changes will change inharmonicity. Making the string longer (raising the tension) will lower the inharmonicity constant while increasing the wire diameter (also raising the tension) will raise the inharmonicity constant.

Increasing the speaking scale length and reducing the wire diameter while keeping the tension constant will lower the inharmonicity constant. For example, a 0.042” string that is 900 mm long and pulled to 155 lbs of tension will have an In4 of 3.2. A 0.041” string that is 920 mm long also pulled to 155 lbs of tension will have an In4 of 2.8. (That is, the 4th harmonic will be either 3.2 or 2.8 cents sharp of the fundamental.)

So much for the nuts and bolts — the second part of your question is the more interesting: “does it even matter all that much?” The general answer is no, it doesn’t matter all that much. Except, of course at the bass/tenor plate crossover or at the crossover point between plain steel and wrapped strings. Here it matters to the piano tuner. If there are appreciable discontinuities in inharmonicity across these points the piano will be some difficult to tune. It is also a good idea to keep the inharmonicity constant smoothly progressive for the same reasons. If there are dips and peaks in this curve it will affect how the tuner must stretch the tuning away from the temperment octave.

But, we do not “hear” inharmonicity as such. What we do hear is the effect of the same scaling choices that give inharmonicity its value, length, wire diameter (i.e., its stiffness) and tension. If we increase the length of the string, keeping the diameter the same, tension will increase and inharmonicity will go down. But it is the effect of the longer and higher tension string that we hear, not inharmonicity. Conversely, if increase the wire diameter both tension and inharmonicity will go up but it is the effect of the increased wire stiffness and tension that we hear, not the inharmonicity.

There will be substantial differences in potential tone quality between a short, stiff (and relatively high tension) scale and a long, flexible (and relatively low tension) scale. But it won’t be because of differences in inharmonicity. (Note: I say “potential” because other factors such as the design and construction of the soundboard assembly, the rim or back structure, the hammers, etc., also affect the voice of the piano.)

Del

So........would it be optimal for a piano builder to build a piano with a scale design that supported the longest, thinnest and lowest tension string possible? That might make an easily tunable piano, but what about the tone? I'm sure there is a trade off at some point. The goal is to build a musical instrument, not a machine that tunes easily. When do you stop or start worring about inharmonicity as it relates to tension and diameter?

I don't worry about inharmonicity at all! It is way, way down on my list of scaling priorities. I don't know how else to say this — you don’t hear inharmonicity! You hear the effect of the choices you make — long or short, high or low tension — in coming up with a string scale. None of these choices are necessarily “right” or “wrong.” They are just different and viva la difference!. A smooth inharmonicity curve is a natural outcome of good string scaling practice and it is available with all of the above choices. It may be high, it may be low. But if it is smooth and consistent the piano will be tunable and the transitions will be acoustically transparent.

I don't know what an "optimal" scale length might be. It depends. Scale length and tension choices should made based on the desired performance goals, not on inharmonicity or on some preconceived notion of what is “right” or “wrong.” What would you like the voice of the piano to be like? Hard and bright? Warm and dynamic? I’m not here to make value judgments. You must take your own pick and build your own piano. Or buy your own piano. Forget about inharmonicity. If anyone is going to worry about it let it be your piano tuner.

Del

If you don't worry about inharmonicity, it's probably because your pianos have a superior guality scaling and you don't have to worry about it. As a pianist I can tell you that inharmonicity affects the color of the piano. Maybe it can't be heard when striking one note, but it's effects can be heard when multiple notes are played together. Those pianos that never quite sound in tune really aren't in tune because the IH is so bad . Conversely, a piano with no IH (impossible) or at least very little would be dull as heck. It would probably sound like an organ. No offense to you organ players out there.


Personally I think IH is the cause of my love/hate relationship with my piano. When in perfect tune and voice, it's unbelievable. A little off and it threatens becoming kindling wood.

Inharmonicity wasn't even discovered until Helmholtz, and really wasn't an issue at all until electronic tuning devices became common. It certainly isn't an issue unless you are playing with another instrument. The instrument that causes the worst problems is the ETD.

Tuning means having the intervals correct. They are correct when they sound good. If an ETD says a piano is tuned, and the intervals don't sound good, it is the ETD (or its use) that is wrong. It is wrong because tuning is not numbers, it is good-sounding intervals.

The classic book by J. Murray Barbour, Tuning and Temperament summed it up by pointing out that of all the instruments in the orchestra, only the harp theoretically is tuned exactly, and it goes out of tune so fast that it is probably out of tune by the time one has finished tuning it.

Inharmonicity has not been shown to be a distinguishing characteristic between the tone qualities of various instruments, not like harmonic content and the sound envelope. Somehow, people managed to live with inharmonicity for decades without noticing it. So I suspect that the problems that are ascribed to it are due to something else. It's usually lousy tuning.

As you say, a piano with no inharmonicity is impossible so I don’t devote a whole lot of time wondering what one would sound like. Inharmonicity exists. It is an effect of string stiffness and until piano strings are made without stiffness we will have to cope with it and/or enjoy it.

Perhaps this is only an issue of semantics, but you are still not “hearing” inharmonicity. You might well be hearing its effect in a piano that is difficult (perhaps impossible) to tune clearly and cleanly because of some anomaly in the continuity of inharmonicity curve but this is not due to its being either uniformly high or uniformly low. It is due to its being uneven within a given scale. And this is a whole other issue from the original question, at least as I understood it.

As noted in one of my earlier replies, an uneven inharmonicity curve within a given scale is the result of poor string scaling (usually) across the bass/tenor plate break or across the transition between tri-chord steel strings and wrapped strings. If this transition has been badly scaled it can, indeed, make tuning very difficult. But, these transitions can be scaled in such a way as to be acoustically transparent even on most existing pianos. If it is particularly obnoxious in your piano you might ask someone skilled in the process to take a look at it for you to determine what, if anything, can be done to improve matters for you. While this may involve a new set of bass strings and/or changing a few tri-chord steel strings to bi-chord wrapped strings the results may make the process worthwhile.

It is also possible that a tenor bridge sweep can be so uneven as to make tuning interesting through the tenor and treble regions, but usually a good tuner can bring this into a reasonable balance. As with most human endeavors some tuners will be better at this than others.

Del

del,
i find your explanations of the priorities in scale design and their effects to be fascinating.

just to be certain i understand you right--is this correct:

if you have a piano with a warm, resonant tone with lots of color and broad dynamic range, are those qualities--which to be succinct, i will call the piano's "personality"--does the piano's essential personality change when you change the hammers to a different brand?

would the piano's essential personality change if you voiced the hammers differently, say, made them brighter?

i'm asking for practical reasons. i believe i've noticed with my piano that no matter how it is voiced, there is something essentially its personality that remains. it can be out of tune, out of voice, and the personality is still clearly there.

i'm planning to replace the hammers on the piano. will i lose the piano's essential personality (which is what i fell in love with) when hammers of a different make than the original are installed?

and to answer you earlier question, i needed to know about the tons of tension for something i'm writing.

pique: i needed to know about the tons of tension for something I'm writing.

Still working on that reportage about on-line communities are you, pique?

Ariel (seriously, are you?)

no, unfortunately. the magazine said they'd covered that topic too much already.

this is for a another project.

I've found that there is something to the sound of a piano that lasts through a lot of things, including new hammers, rescaling, and everything else that you can imagine doing to one. My Mason & Hamlin has gone through all of that, and it still sounds like a M & H. The rescaling mitigated some of the problems I felt the original scale had, such as a pronounced weakening of the tone near the bass break due to the extreme drop-off in tension there, and a tendency for some bad harmonics to show up about G# above middle C, but really, rather than sounding radically different, it just sounds more like my ideal of the M & H sound.

I think the most radical rescaling I have done was on a Knabe grand. For the most part, it sounds like the same piano, but it is much easier to tune, and it stays in tune very well. The harmonics don't seem to be quite as screwy as I have experienced in other Knabes.

As for voicing, there are especially hard hammers that don't allow the true tone of the piano to develop. I think that has been covered in these forums before. But the magnificence of the Steinway tone is there with the very soft Steinway hammers even without hardening, for instance. And as Del as said, you just can't voice a Yamaha to sound like a Steinway, no matter how hard you try.

Even after a complete rebuild, and I mean total with only the case and plate as original, I still could tell it was the same piano. Much better mind you , but had the same personality. I didn't expect that. Not disappointing, just surprising.

piqué,

Why are you replacing your hammers? Isn't your Grotrian relatively new?

ralph,
perhaps that is the reason i have heard rebuilders say that the soul of the piano resides in the plate.

dan,
the hammers were never right, so this is a replacement under warranty. we've tried for two years to voice them, with very limited success. my tech finally said he thought they were probably not good hammers from the factory, or that something happened between when i first played the piano and when it was finally delivered to me (a period of about 3 months). he felt they had never responded the way renners should, and he is a renner tech with 30 years experience.

in any event, all i had to say to the dealer was that very conservative and careful voicing had not resolved the problem, and he volunteered to get me a new set. he's in germany now, and will bring them home with him.

Pique,

I am curious. Can you be more specific as to the problem you were having with your hammers? If you covered this in another thread, I missed it.