Not as crisp or close as I'd like to see, but these pictures of recent Grotrians don't show a tuneable front duplex (no aliquots, only a bearing bar and agraffes; also note the felt under the string section between agraffe and bearing bar):






Nor does this picture of an older model:

Chica,
By these pictures it doesn't look like this is a duplex scale...or what is usually meant when someone is saying “duplex scale”, which is actually a tuned duplex scale...and should actually be called more accurately a tuned aliquot segment as Del pointed out.

But in any case, it doesn't look like what usually people refer to as a duplex scale design, in the spirit of the "duplex scale design" found on certain pianos plates, and definitely isn't a tunable duplex segment (or aliquot segment).

Del,
I'm glad that you didn't take offence to me disagreeing with you, as none was meant and none should be taken.
As I said before, I respect you and understand that you wish to present observations and conclusions you reached to over the years to others.
I have also met though some other piano designers that were happy to share their observations and conclusions with me, and that the results of their experience and knowledge, which was the pianos they designed, left me very impressed.
It just so happens that few of these designers, and obviously some other designers whom I didn't meet with, have an opinion about this matter that is different then yours.
Hence the pianos they design have this element commonly referred to as duplex scale (tuned and tunable aliquot system), and the pianos you design don't have it.

I'm sure these designers, that are also very knowledgeable as you are, also won't lose any sleep at night by knowing that there are skeptics that refuse to accept their observations and conclusions about everything.

I think that this diversity is what makes the instruments offered in the market so interesting and different from each other. If there was only one opinion by one designer that was right all the time, then many of the high end instruments (that are willing to pay for high quality construction of their pianos) would sound just the same.

I for one enjoy this diversity and wouldn't want all pianos to sound like Charles Walters.
I'm happy that in addition to this fine piano there are also Bluthner, Mason & Hamlin, Estonia, Steinway, C.bechstein, Fazioli, Bosendofer and many other makes that can be so different from each other and represent the philosophies of their designers.

I’d like to thank you for your comments though as they are highly appreciated.

Del, I wonder if you'd care to elaborate on this point. Does this phenomenon exist simply because a softer material will almost always preferentially wear when in rubbing contact with a harder material? Is it possible that in wearing a groove in the pressure bar, the string effectively polishes the bar? Does the string, by wearing a groove, soften, or increase the radius of the contact area?

Also, I wonder if anyone has tried any of the sintered metals into which lubricants of various kinds can be imbedded.

Moderators: I wonder if it would be possible to have a button added that would automatically sort the content of threads like this into, say, four seperate columns, labeled:

1. Marketing Terms
2. Technical Equivalents (where there is one)
3. Facts Based on the Physical Sciences
4. Beliefs

This would be most useful, as I find generally find it impossible to reconcile the views and opinions of those who subscribe more to one column or the other, I'd just like to see the sorted text, and try to figure it out myself.
:-)

Del, et. al.,

My Grotrian (whose pictures launched this discussion) is a 2005 model. The front duplex area is not seemingly designed to affect the tone. Unlike the back duplex which clearly sounds when plucked (and in a consistent pattern) the front duplex area is muted.

I guess my background in engineering and science is causing me to discount much of what is being said in this discussion.

There is absolutely no data being presented. Only opinion. This goes for everybody's posting so far.

Theorizing about something does not make it a fact. We know this from the Kansas State School Board.

The Grotrian has a huge angle between the capo bar and the tuning pin plate and the duplex there SINGS LOUDLY. Therefore the energy transmitted is not conducted along the string alone.

To claim that a duplex is "sized" to vibrate with the main note is garbage when it is plain to hear that ALL the duplexes are ringing even if you strike only one note.

To make statements about duplex loudness or sustain intervals without data is merely expressing an opinion. This does not represent a fact.

Numerous other unsupported claims are stated in this discussion and I think we need to examine them one by one.

I am at work and can't take the time (been away on the weekend). But I think we can come up with experiments to verify and validate or prove wrong statements that are being made here. But I do regard a lot of what is being said as opinion and nothing more.

Let's figure out a more intelligent way to pursue this knowledge-quest. Eh?

Ahem.

g,
at this point i am thinking that there are two definitions of "duplex" being bandied about here. there is the literal definition, by which the grotrian scale is obviously a duplex.

and then there is the conventional meaning of the term as it is used in the piano industry, and from this it is less clear to me. it seems our piano industry friends are telling us that by the industry's standard definition of the term, the grotrian does not have a duplex scale design.

further comments, anyone? is my understanding correct:?

I thought this area in a Grotrian was muted with felt. If so, how can is "sing loudly"?

Derick

Thanks. This piano does not have a tuned aliquot stringing scheme. (Therefore it must not have much sustain in the treble sections. Right?) The string deflection angle seems to be (it’s a bit hard to tell from the picture) relatively sharp and short. Through the top two sections there does not appear to be any muting felt. Nor should it ever be necessary.

The backscale will always have a clear sound when plucked and (in a system using a bearing rod such as that shown in the picture) will always have a consistent pattern to it. What any given string backscale segment that is plucked won’t have is a pitch directly related to the speaking length of the string. Except by accident. (Which, come to think of it, pretty much describes most of the so-called tuned duplex—i.e., aliquot—backscales as well.)

Del

well, members of club grotrian, let's not all jump del at once.

del, this piano has amazing sustain. sustain is one of it's most compelling and seductive characteristics.

oh, i almost forgot to post part of the explanation the grotrian factory gave for NOT employing the duplex design.

they said the duplex design was created to lend more power to a low-tension design. the grotrian has thicker strings, i.e., it is a high-tension design, and so the duplex scale is inappropriate for it.

this is from the email they sent me:

I'm not enough of a metallurgist to adequately answer this. It is not appear, however, to be a matter of friction and “wear.”

It is primarily a problem through the upper sections where the hammer blow is relatively close to the string termination—usually a V-bar arrangement of some kind. When the material used for the string termination is as hard, or harder, than the material from which the string is made the string is actually damaged by the repeated blows of the hammer. I suspect the reason for this is that with gray iron—and, to a lesser extent, the various bronzes I mentioned—enough energy is absorbed into the capo tastro bar to take some of the work stress off of the string. But that is just my speculation. What I know for sure is that when the termination material is made hard and the radius is down below about 0.5 mm (assuming the same string diameters, tensions, deflection angles, etc.) treble strings start to break after about half the number of blows that it takes to start breaking their counterparts using a “standard” V-bar shape and material.

Del

It was a joke, piqué, a joke. I know the Grotrian has good sustain.

Del

i see i need to lighten up a bit here. i'll try.

Axtremus said: I play both a Grotrian and a Nordiska on a weekly basis (both new 7-footers). I can tell you that it would take more than removing some felt to make the Nordiska sound like a Grotrian. A whole LOT more!

It’s not all that difficult. The test setup I used when I was looking into this system was a simple monochord with a fixed V-bar and a movable bearing bar/tuning pin block. I could change both the string deflection angle and the duplex string length. I could also move the bridge (along with its rudimentary soundboard assembly) and hitchpin block to accommodate various string lengths, diameters and tensions and work with various backscale configurations.

Have fun....

Del

Hey Pique .... ever heard of deadpan humor?

Alas, it usually soars a few feet over my head too!

Del, I do think the Grotrian has unusual sustain in addition to a particular hollow-sounding tone (in a beautiful way). This is, of course, just a personal impression. Has sustain ever been quantified across brands and holding other things equal?

David F

ummm.... that's humor without the use of graemlins, right?

Del - while you are perhaps the only one here who is equipped to run many of these experiments. You are not providing any data. I know that this is because you are going after what you are hearing.

But a test that is devoid of subjective interpretation includes a measurement technique that everybody can agree on and is independent of interpretation. Like a digitization of the decay envelope of the string with and without a tuned duplex on it so that we can measure the decay of the note. Or a measurement of the acoustic output of the front duplex of a Grotrian (with what I would call a pretty sharp bend up in the string) compared to another piano, using say an electromagnetic pickup similar to a guitar pickup.

These are the types of measurements people need to provide data from in order to make the sweeping generalizations they are making.

I know this has gotten off topic from "what does duplex mean" but I am just a little miffed by all the opinion people are passing off as fact.

So by the way - do you have any "hard" data?

Also I was fortunate enough to have several posts accumulate before I returned to read Del's comment about no treble sustain. It did get my heart racing though...

I'm confused. (As usual.)

Are these duplex and duplex-like thingies activiated by vibrations bleeding from the same string, by vibrations via sound from other strings (different notes), by vibrations via sound from same string, or some combination(s) thereof?

Isn't the Bluthner fourth string activated by sound, presumably by fundamentals and perhaps to a lesser degree by partials?

I thought the Gotrian observation about string tension was interesting, as I'm under the impression that Estonia's string tension is a bit under average, and they have opted for the (allegedly) tunable flavor.

Gotrain is one of my all time favorite pianos, which goes to show that I like both extremes of this design "feature."

No, I’m not. I probably still do have at least some of the test data available somewhere. But I’m not going to go looking for it. I already spend way to much time at this—if I spend much more time at this and I’m going to have serious wife problems.

Besides, I do this stuff for a living. At least I try to. I’m willing to set up most any experimental process anyone wants, but I’m not independently wealthy and the nasty problem of earning a living keeps interfering. These setups take time, the tests themselves take time and the equipment needed to measure the results is expensive. Some I still have, some I would have to purchase and I don’t have any compelling reason to do that just now. It’s not necessary for the work I’m currently involved in. As for the time, I don’t remember how long I worked on this project while at Baldwin but by the time I designed the tests and the test setup, built it all, and then conducted that actual tests it was more like a few weeks than a few days of tedious and repetitious work. I’m not about ready to go through that again unless I’m going being well paid to do so. Even then the results would go to the client and it’s doubtful most clients would want to share that information publicly. Nor am I convinced that kind of data would be all that useful to even the most dedicated piano buyer. I’d like to bring a higher level of understanding to the folks running the gauntlet between themselves and the piano they would like to spend their lives with but for the most part I think those decisions should be made by spending some time with the pianos, listening to them and living with them. Just like I found all the technical details of the high-tech engine and suspension system in my car interesting, in the final analysis it’s how the car felt on the road that was most important.

The posts I write to this list are not intended to be full research reports. They are simply summaries of some of the stuff I have learned over the past 40 plus years of piano servicing, rebuilding, remanufacturing, building and researching and testing. Mostly I try to explain, in layman’s terms, how the piano works more in broad strokes than in great detail. Hopefully I can bring light to some of the mythology and misinformation that still swirls around the instrument. That’s all. I really don’t have time to go beyond that. Hopefully it is useful as such. If not, well, it’s the best I can do for now.

Del

Grotriman,
My experiments are much more simple. I carry some of the lines that have tunable duplex scale segment. The aliquots in some of the lines that I'm very familiar with can be moved, tuned or replaced in small segments or individually and I have experimented with them many times before under real conditions. Meaning, a complete instrument that has been design to have a properly working duplex segment.

The only results I can measure are those that I hear, and that may not be good enough for you or others...yet I spend my time and work with those aliquots often enough to feel that I can change and improve certain things in the instruments sound.
I'd like to think that others recognize the advantages of what I do, otherwise I'd be wasting a lot of time...and the only way I know how to measure if the time wasted was worth it or not is by the end result.
The people playing the pianos I prep in our showroom often wouldn't care if there is a duplex or not, they just want the piano to sound beautiful.
Sometimes I wish I felt that working with these aliquots is unnecessary, as it would save me time, but I think that it's something worth working with.

In my first post I wrote about the tunable duplex segments:
And in my next post I added:

I believe that this is about as much as I can say at this point and think that these remarks, given in the beginning of the thread were as clear as possible saying that this isn’t a black and white issue, and that there are those that are skeptic about it's advantages.

Grotrian’s explanation to Pique makes sense to me, and this can show again that there are many variables regarding a piano design, and many contradicting philosophies by piano designers.
There is no one person in the industry that is right all the time no matter how knowledgable he is simply because much of what’s right is subjective.
So again I would suggest to people to judge things in this regard by the tonal results of the complete piano.
No piano will fall apart because it doesn’t have (or have) a duplex scale.

Should you want to know more, you're welcome to come here and visit me. Our showroom is only 45 minutes from NYC by car or train.
Until then, all I can do is post pictures of different instruments with different duplex scale systems for you and anyone else to better understand the issue.

Here are the pictures:
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Mason & Hamlin front duplex. The aliquot segment can be moved in sections and by replacing these with higher bars or moving them back and forth the string angle and length can be adjusted:
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Mason & Hamlin back duplex. The aliquots are tunable individually and the strings in the aliquot segment are relatively long:
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Estonia front duplex. The aliquots are tunable individually, by replacing them with larger or smaller bars, and moving them back and forth the string angle and length can be adjusted for each note:
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Estonia back duplex. The aliquots are tunable individually and the strings in the aliquot segment are again relatively long:
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Bluthner front tunable duplex. The aliquot segment can again be moved in sections:
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Bluthner fourth aliquot string. Can be tuned to sympathetically resonate to the other three. The fourth string is slightly elevated and is not struck by the hammer:
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Steinway front duplex segment. This is tuned to the speaking part of the string but isn't tunable.
The aliquots are a part of the plate design and can't be moved:
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Steinway back duplex segment. The aliquots are in long segments and can actually be moved very little.
The duplex segment of the strings is relatively short in comparison to the individually tunable segments on the Mason and Estonia.
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The pictures came up as a link...
Can anyone tell me how to get the pictures to come up without the link?
Ax maybe?

I think I got it done thanks to pique!

ori, i think what you did was bracket the photo locations with

what you want to bracket the info with is [img] [/img]

here let's see if i'm right:



Steinway back duplex segment. The aliquots are in long segments and can actually be moved very little.
The duplex segment of the strings is relatively short in comparison to the individually tunable segments on the Mason and Estonia.

Well, that got me interested. So I looked on the front of my Baldwin L's strings and lo and behold, I see the same thing, though perhaps not going as low as in your picture. (My Baldwin was built about 1967; don't know what more modern Baldwins have.)

Chris

yup. just bracket each link with the code [img] [/img] and you will be all set.

Mason & Hamlin back duplex. The aliquots are tunable individually and the strings in the aliquot segment are relatively long:

The back end of my Baldwin L's strings are terminated exactly the same way, all the way down to middle C.

Chris

pique,
Thank you for your help with the pictures.
For the amount of time it took me to figure it out I could have driven down to the city, pick up Grotriman, bring him here, show him the actual pianos and then drive him back...


Chris W,
Among the many pianos I have here there is also a 1980's Baldwin L. This one has different duplexes then what you describe. The front is fixed/un-tunable and a part of the plate.
The back is not a duplex scale at all and is nothing like the Steinway D picture that curry posted.
If you'd like then post pictures of your piano to verify that the models are different and that there isn't any misunderstanding here.