Piano World Home Page Forums Our Most Popular Forums Piano Forum Laminated soundboards

Those who have read my various missives on how piano soundboards work will be aware that I have long advocated the use of high-performance, engineered laminated soundboard systems especially in smaller low- to mid-priced pianos.

The Fall, 2015 issue of the “Piano Buyer Magazine” is now available online. In this issue there is an article of mine titled The Benefits of Laminated Soundboards. It can be found on page 51 and this link should take you to it:
http://www.pianobuyer.com/fall15/49.html

As always, questions and comments are welcome.

ddf

Excellent article, Del!

I was not aware that laminated soundboard technology dated back as far as it did... a great bit of history included in your article.

Here is a post I made in Larry Fine's thread announcing the new edition of Piano Buyer...

In my view, anything Del Fandrich writes/says... is like the old "E.F. Hutton" commercial used to say, "When E. F. Hutton speaks, everybody listens"; when Del Fandrich speaks, everybody listens! (At least I do ).

I owned one of the Kimball Viennese model grands, with the laminated soundboard, (the 5'8" model) and that piano held a tuning better than any piano I've owned to date (and I pounded it pretty hard). So, even without reading the article, I'm sure that tuning stability is one of the benefits of using the laminated soundboard.

I'll look forward to reading that article (which I just did ).

Best regards,

Rick

Del, are not laminated panels heavier?

I find they deliver a lit of power, at the expense of tone variability.

I wonder how much build in stress can be obtained, as I see no other way to fight the inertia of laminated panels.

The technology certainly did evolve, allowing nicer results.

That seem to be the top of the spectrum thar is damped, but now, this can be compensated by the use of a wire that produce more partials, I suppose (thinking of Pitthan wire here)

Regards

Thanks Del, for an informative and well written article.

Did you find, using the B&K equipment, a characteristic difference in the modes of the laminated soundboard versus solid: first mode resonant frequency, magnitude of vertical motion, bridge/soundboard impedance across the compass, for example, or was it mostly the same or just an overall change in the magnitude of the variables?

Cheers,

prout

Del, it's common for soundboards to be tapered on some of their edges. How does one modify the design of a soundboard and ribs to allow for the fact that laminated boards aren't tapered?

Just like a solid panel that depends on the materials used and its construction. A 7.5 mm laminated spruce panel will weigh the same as a 7.5 mm solid panel. (Assuming variations for the character of individual pieces of wood.)



I find that some pianos with solid panels "deliver a [lot] of power, at the expense of tone variability." In other words, just like solid panels have to be designed and constructed for a desired sound, so do laminated panels. Not all solid panels are the same. Neither are all laminated panels.



Why fight inertia? Leave out what you don't want. Inertia in a soundboard system is the aggregate of all of its various parts and components. That includes the bridges, the panel, the screws, the bridge pins, the ribs, the finish material, etc.



Again, the spectrum produced by a piano with either soundboard system is a function of its overall design and construction. Not just one thing like the construction of the soundboard panel.

Blanket statements like, "...the top of the spectrum that is damped," are no longer relevant.

ddf

Del,

Do you envision laminated soundboards someday being made available for piano rebuilders to install in pianos needing rebuilding? There are so many older pianos with defective soundboards that so often don't get replaced for various reasons. I would think that there would be a market for these soundboards if made available to the piano rebuilding community.

Ed

Nothing that jumped out. But these were very limited tests.

ddf

Solid panels are often tapered on some of their edges. Steinway soundboard panels—and the many that have been copied from Steinway construction—are typically diaphragmed; i.e., they are tapered all around the parameter of the panel. In the treble this tapering contributes to the (relatively) rapid rate of the collapse of the system—i.e., the killer octave and can be counter-productive. That said, soundboard panels—both solid and laminated—can also be too thick in the treble. That is easily dealt with using a solid panel. Simply plane it down. It is not so easily done with laminated panels. Typically a laminated soundboard panel will be sized to accommodate the treble.

Thinning the sides of a solid soundboard panel makes little difference as spruce is already quite flexible in the perpendicular-to-grain direction. The bridges are located rather far from the rim where the soundboard panel is supported so neither panel thickness or flexibility is much of an issue. As well, the motion of the bridges at the middle frequencies is [very[/i] small..

This leaves the bass. In longer pianos just keeping the bass bridge a reasonable distance from the rim provides adequate mobility. In shorter pianos some heroics are called for. The easiest of these is to simply float the lower parameter of panel.

ddf

I would think so as well. I don't see it happening any time soon, however.

ddf

Morley used laminated soundboards in their clavichords - very much to the detriment of the volume (which is practically non-existent anyway). I assume it was to ensure against splitting.

Thank you,

Can you give links to some samples of pianos with laminated panels ?

I know the B series from Yamaha, for instance.

It is always a little frustrating to me as you are always so vague with statements as "good design", without much popularization on the basis of your thinking.

There is a residual stress obtained with the string pressure, and the balance of the panel against that pressure is certainly playing a role in the first moments of tone.

The high frequencies are better transmitted when the panel is "lightened" with the inner stress (energy reserve installation) obtained when forcing the panel into a cylindrical or elliptic shape.

I suppose that with the best orientation of the core, the sound speed in the panel is not slowed too much, but it seem that the speed of the tone is a major element, hence the "lightening" of the treble side as obtained with Steinway soundboards (by installing much stress with all glue joints)

I hear you when you say that laminated are more suitable for small pianos, if cracks are not really the problem, probably less stress can be installed (the stress within the panel being a protection against cracks, some "give" is allowed)

SO the thinking is certainly very different. But you are not giving much pointers there.

Regards

For instance, that small vertical have significanly more power than any model of that size with a concrete soundboard.

[video:youtube]WvgmKcxRxHo[/video]

The tone is well defined, but dynamics is reduced may be because there is much power immediately (at light level of playing)

My gut feeling is that low inertia is what allow tone transparency.

Del, Thanks for the article. You've addressed many of the issues I've been wondering about. The one big question still remaining is life expectancy? Traditional spruce boards are, in my opinion, shot by the time they are 50 yrs old. Has anyone been able to do any testing of the effects caused by the woods natural deterioration?

Have you actually read the article I wrote? In that article I describe two rather different soundboard panel, one from Samick and one from Hailun. I went about as far as I could go without divulging what these companies would consider trade secrets. These soundboards appear in many different models built by these two companies.

Laminated soundboard panels also appear in some of the new models coming from YC/Weber but these will mostly be seen in China.

One of the problems with laminated soundboards in current production is that they are still used mostly in low-cost pianos. Typically these pianos have construction limitations quite separate from the design of their soundboards. I expect this to change as our attitudes about marketing them changes.




Please forgive me, but I do not understand what all of this means. What is “a residual stress…?” I am guessing that you are talking about string downforce against the bridges and the soundboard’s pressing up against that force. If we want soundboard crown with a laminated soundboard panel it has to come from crowned ribs.

The rate at which an energy wave is carried through a panel such as a piano soundboard is a function of its stiffness as well as its mass. I don’t know what you mean when you say, “the high frequencies are better transmitted when the panel is ‘lightened’ with the inner stress (energy reserve installation) obtained when forcing the panel into a cylindrical or elliptical shape.”




Laminated soundboard panels resist cracking because they are laminated. That is, there is a core and there are face veneers at some angle to that core. These panels inherently resist cracking.




What kind of pointers are you looking for? I’m not going to publish specific details on designing and building a piano using a laminated soundboard panel. That is what I get paid to do. On the various forums that I participate in I try to answer questions of a general nature.

ddf

Thanks Del, you answered to me by stating that the ribs are crowned, so there is no "slippage of the panel on the ribs during the gluing.

The stiffness is mostly due to the ribs ?

Not any stress installed between the layers ? That is the kind of thing I was curious about? The use of different layers allow to do that I suppose, by playing with dryness, but I have my doubts it is actually done that way.


Best regards

I wish the article had spent more time talking about the quality of the sound from the laminated soundboard.

It's cool that it lasts longer, and holds a tune better. Those are good things. But ultimately I am not going to sacrifice sound quality for those aspects.

You did talk about it a little, I just wish you had focused more on that, because it is the primary concern.

A more basic and probably simpler question: Do laminated soundboards resist cracking because because of the laminations or because the veneers are at some angle to the core or a combination of both factors?

Edit:Now that I've read your article I think that having an angle between the veneers and the core is the crucial element. Am I correct?

Regarding the article as a whole, I am continually impressed by your ability to explain things so clearly that a layman can understand and with a very fair(advantages and disadvantages)approach.

I can't speak for Del, but the 5'8" Kimball Viennese baby grand I had, with the laminated sound board, had a pretty decent tone, in my view. I really liked that piano and enjoyed every minute I played it.

The only reason I sold it was because I found a Baldwin R I wanted. You know you have too many pianos when one has to go in order to get another one.

Here is a YT flick of the Kimball if interested. 5'8" Kimball Viennese with laminated soundboard

Rick

Congratulations to Del on a great article. Thanks so much for putting that all together. Great reading for customers and technicians alike.