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Well what more is there ? That is enough surely ? So I do not really understand?

Thanks! I'll start a new thread for that question.

I’ve only played two Bösendorfer grands in my life, for much too short a time on each occasion. I love both the sound and the feel.
Because of where I live in the US, I haven’t gotten the chance to try many other great European makers like Bechstein, Blüthner, Sauter, or Steingraeber. I’ve only tried Bösendorfer, Schimmel, Estonia (only one which I purchased), and Petrof (my friends that wasn’t for sale). I guess analysis of what makes a Bosendorfer sound and feel like it does is useful. The only way I can describe it is when I’m playing a Bosie , it feels as if the whole piano is responding and singing as I play. It reminds me of riding my horse when we would canter down the trail. I could feel his breathing and response to my cues.

I love that description. I've had customers describe the sound like going from stereo to surround sound. And often, we talk about the relationship between the tool and the pianist...some great pianos are like very sharp knives in the hand of a trained chef, and it is the skill that shapes the music. However, the analogy I used is that the Bösendorfer is like a well trained dance partner, that if you lead, it knows where to go.

Per this discussion, I would propose that Bösendorfer's rim means more to its soundboard design than with any other current maker.

With a laminated rim construction, the rim certainly affects the design of the soundboard, but makers like Schimmel & Kawai have demonstrated their designs substituting plexiglass for wood rims altogether. Having experienced the plexiglass Schimmels, the performance is objectively better...wider dynamic range, flatter sustain while maintaining an excellent tonal range vs. the identical instrument in wood. For that design, the added density of the plexiglass is the obvious factor.

With a less dense laminated rim, both the soundboard and string scale would be optimized differently to achieve wider dynamic range and flatter sustain. Anecdotally, it does seem to me that with a laminated rim, denser rims have an advantage in producing more (or a greater percentage) of the fundamental tone. I see many examples of this, but you can never isolate the one variable with so many other variables.

I've mentioned this before, but the piano by which I measure all others is an old Bösie! It's in the choir room at my hometown church. I love it.

PianoWorks ATL
What do you mean by a "flatter sustain" ?
I like a good sustain even a "rather lively one ".,What I do not like is if the decay of sound is sudden.
Although I do not think anyone wants that.

There might be another explanation. Perhaps the plexiglass version is better and clearer because the plexiglass is not only denser but vibrates and transmits sound much less than wood, which is why it was used by some high quality hi-fi turntables. Thefore we might suspect that a plexiglass rim would contribute less to the overall sound and let the dynamics of the soundboard stand out for themselves. Maybe.



I find it difficult to believe that any sort of wide band or even sound production from a rib can be achieved. It will have frequencies at which it resonates and reinforces the overall sound so maybe careful choice of heavier materials that resonate at lower frequencies will benefit (some of) the lower notes where the soundboard response is rolling off, but I doubt very much if there is any improved dynamic range or flatter sustain generally, only for the notes where the rim might resonate.

By flatter sustain, I mean that the sustain decays less after the initial attack. Many pianos have a strong attack, but the initial decay is very strong, such that the long sustain is at a much more quiet level. Bösendorfer seeks to have their sustain to be of a flatter level, more like the sound of a bow across a stringed instrument. This gives the pianist more control over the overall expression.

This discussion echoes another thread about sound barriers. If the rim is designed to be very dense, then less of the sound is transmitted to the rim. In simple terms, more of the vibration energy is reflected back to the soundboard from the edges. But the soundboard and string scale have to be designed around this. In the case of the turntable, the density is isolating the vibrations on the turntable.

I'm not sure if you meant "rib" or "rim". I'll presume rim. You can design around a less dense rim in several ways by changing the shape of the soundboard and the string scale. Perhaps one with less crown and higher tension (or lower wire gauges and less tension) will pair better with a less dense rim. Crown and downbearing make the soundboard behave under stress. You can instead design a soundboard that operates under different forces, and I safely presume that the rim and rim connection would be optimized differently.

Bösendorfer speaks about the resonating box principle. If the soundboard on a laminated rim works similarly to the head of a drum, the rim construction of the drum (laminated wood or other materials) has some affect on the tone. But in the resonant box principle is what guides the construction of a violin or cello...the rim is an extension of the soundboard.

Because these are simplified explanations, the details make the result. Bösendorfer's methods make their design work. Using a laminated rim as a design platform can be executed better or worse, depending on the goals of the manufacturer. You can successfully make a laminated rim out of maple, beech, birch, oak, plexiglass, etc.). You can make it beautifully, or you can mass-produce it and the results will vary.

But if any maker tried to take a shortcut in the steps that make a Bösendorfer soundboard & rim construction, the result would automatically be poor. Bösendorfer's methods, including how they cut, season and dry the wood, make it an all-or-nothing result. Though there used to be other makers that employed this type of construction in Europe, there will never be a copy or "knock-off" of a Bösendorfer. There are no shortcuts.

I guess it’s the no shortcuts that make Bösendorfers so expensive.

There is so much bad information regarding piano design/acoustics here I almost don't where to begin. I understand completely if someone likes the Bosendorfers (and I've played on a few nice ones) but to perpetuate their resonant box theory is a little over the top.

This was stated:
"Bösendorfer speaks about the resonating box principle. If the soundboard on a laminated rim works similarly to the head of a drum, the rim construction of the drum (laminated wood or other materials) has some affect on the tone. But in the resonant box principle is what guides the construction of a violin or cello...the rim is an extension of the soundboard"

So lets just use some simple common sense here. EVERY instrument that IS based on an resonant box has a trait in common. ITS a thin walled Box. The violin for example the back is a thin walled piece of maple behaving as a membrane.
Lets compare that to a Bosey. A membrane on top, and on the bottom - a massive criss cross beam structure. One would have an easier time in court proving its meant NOT to resonate.

Both the laminated rim and the Bosey style of rim are both behaving as drums. They're just built differently and each offers its own tonal spectrum.
-chris

The "newer" Bosendorfer scale designs have laminated rims. (I am talking about the 5'8" and 6'7" and newest 9' models compared to the older 7' foot and two 9' and 9'6" models).

So evidently Bosendorfer doesn't think the pieced up spruce rim used in the good old days of Ignats and Ludwig Bosendorfer is vital for the entire brand.

I think the old rims were kept in place because they couldn't afford to invest in converting the old scales to laminated rim construction. And the sales department had to generate a "reason" to explain the inconsistency.

I’ll ask again for perhaps an explanation for an amateur. I played a 6’7” in 2012 and the newer 214 VC Bösendorfer in 2019. Both pianos gave me the feeling that the whole piano was responding to my playing. I was told when I tried them about the special rim design. What gives those pianos the feeling that the whole piano is responding and resonating with my playing? The laminated spruce rim? The scale design with the laminated spruce rim?

Stiffness and flexibility are 2 ways to express the identical thing. Mathematically, they are just the reciprocal of each other.

Roy 123,

You missed the point. Other rebuilders seem to be "focused" on just Stiffness. Almost as if the more the merrier. What I'm saying by throwing flexibility into the conversation is to say that there are limits. The purpose of scalloping is to induce flexibility and to adjust and center the driving point under the bridge (no one else does this but that is its purpose) Most boards I have studied exhibit too much mass. And trying to gain stiffness via mass acoustically has a high price to pay in the form of added weight. Then trying to solve the weight problem, the size of the board is reduced. And on and on down the designer rabbit hole until the end product resembles a Bongo Drum instead of a Timpani Drum. Nothing against Bongo Drums. The resonance I am achieving right now is ten fold what i was getting a year ago. And that makes me happy.
-chris

I never heard someone say a soundboard should be as stiff as possible, though there may be some people, who are ignorant of how soundboards work, that may tout that. It's easy to do a reductio ad absurdum on that belief--a steel reinforced concrete soundboard could be very stiff. I also never heard anyone say that soundboards should be made small to solve the weight issue. What I typically hear is people talking about impedance and balancing stiffness with weight so the board provides sufficient sustain and doesn't produce a "pingy" sound with rapid decay. I previously discussed how soundboards can be made both stiffer and lighter at the same time by introducing the concept of how the aspect ratio of ribs can be so tailored. If I recall correctly, you poo-pooed that idea as worthless. I have heard people discuss the distribution of the area of soundboard as is best for various portions of the pianos scale, which sounds like a sensible idea.

BTW, the last thing you want in a soundboard is resonance--various resonances will amplify and suppress various notes across the scale, producing an uneven response. Perhaps you are calling some other parameter resonance--I'm not sure, but it would be useful if you clarified what you mean by soundboard resonance.

Yes because a tall and narrow rib introduces irregularities that induces strong spatial localization in some specific frequency.
-chris

That seems rather a strange claim--especially stated without explanation or data. A rib is a linear stiffening element that contacts the soundboard in a narrow width. It stiffens the board and therefore raises its resonant frequency, and, of course, also adds mass to the soundboard assembly. Because the stiffness of a rib is so highly dependent on its height, it is easy to imagine that someone, without doing the calculations that I showed in the spreadsheet I provided free to anyone that was interested, could make ribs that were too stiff, and therefore push the parameters of the soundboard too far from its optimal values. That sounds like a plausible scenario that in no way denigrates selecting the stiffness and mass of the rib to provide the desired result. There's really nothing too magical about ribs--their mass and stiffness have to be optimally selected to achieve the tone and sustain that one desires.

You tout compression-crowned boards as being able to provide the desired stiffness while keeping weight down. I guess we could call that optimizing the stiffness-to-weight ratio. One could take another soundboard, equal in all other respects, but not compression crowned, and by adjusting the aspect ratio of the ribs, create the same stiffness-to-weight ratio. It likely wouldn't take much change in the rib's dimensions to accomplish that goal. Would that create " irregularities that induces strong spatial localization in some specific frequency," I doubt it, but I guess I'd need to understand what you mean by that phrase, and hear some test results.

Of course there is nothing magical about the ribs, but they do more than you suggest. First, you can can have two pieces of wood that are the same dimension and they will deflect differently. Then the scalloping. Do you scallop 3 inch out, 4", 5"? Symmetrically or asymmetrical? You can have the same piece of wood and scallop it, measure its deflection, then scallop it some more and you've changed its deflection value. Then there is the relationships between the ribs. This is important to create a smooth stiffness curve. Just controlling the size of the area of a rib ignores their acoustic function. BTW, the scalloping is in a cause and effect relationship with the bridge. And needs to be adjust accordingly. No one talks about that. I have already hinted at the spacing in between the ribs and the relationship to rib count.

All the best.
-chris

Ed, you are mistaken. Bösendorfer did not change to laminated rims. Not for new models. It's just not the case. I included the photos. I'm not sure what you saw that led you to believe this was otherwise.

In the new VC models, the rim uses the same principles as before but with the addition of a "transition" layer. Bösendorfer's soundboard is mated with a hoop made of beech. The beech is solid, not laminated, and the hoop follows a more ideal shape of the soundboard while offering a solid connection to the cut/block construction of the solid spruce rim.

And Chris...the difference in a laminated rim made of non-acoustic hardwoods to create rigidity and density to isolate the soundboard more from the rim...is specifically different than using a rim with less density made from acoustic wood designed to continue the transmission of the sound.

Perhaps you might investigate the use of softwoods in drums? Or the use of laminated/dense rims in violins? These are major departures from what is traditional, and could have merit...but illustrate the difference in basic sound design philosophy.

Since the total sound energy is determined by the energy in the hammer, presumably if the sustain is flatter, and so maintains its loudness for longer, it must die away quicker?