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Question:

1] Can laminated soundboards be 'crowned'?
[ including rib-crowning]

Suspect, NOT.....

2] Does it matter to the tone of the instrument,
if it can or cannot?

Suspect, YES....

norbert

It depends on the laminant material, Norbert. If you are speaking of a solid core spruce board with a veneer, yes it can be and is crowned. Even the laminated luaun boards of the 1960s and 70s had crown. But it makes sense that not all laminated materials could be crowned.

Hmmmm....

Are you referring to any particular model or type of construction?

1] Yes, laminated soundboards can be crowned. But only by attaching crowned ribs and/or by building the crown into the laminate. (I have done this experimentally but I don’t think it has ever been tried in production.) Laminated soundboards cannot be crowned by the traditional compression-crowning techniques (though many have tried!).

2) Yes, it matters. For as yet unexplained reasons the piano string/soundboard interface seems to work best when it comprises a system of opposing forces. These opposing forces are typically formed by making the soundboard assembly an upward bearing spring and then partially compressing it by making the strings bear down against the bridge by deflecting them from a straight line between the front termination and the rear plate termination. At rest they find a point of equilibrium which is only disturbed by the vibrating wave energy in the strings following hammer impact.

I have experimented with soundboard assemblies having no crown and with varying amounts of mass and stiffness excited by strings having no downward string bearing. There may be a way to make this work efficiently — that is, with an acceptable attack/decay wave envelope — but I’ve not found it yet.

Del

Thanks guys, great answers!

My interest was triggered initially after I went into Yamaha's Canadian website web page ....

...then checked under 'uprights' the soundboard specs on their new C113T.

This piano was described as having a 'crowned' soundboard while showing 'laminate' soundboard on buttom of page.

norbert :rolleyes:

Wood laminates can be formed into fairly complex shapes. During the Second World War there were a number of aircraft whose airframes were made entirely of plywood, the De Havilland Mosquito twin engined fighter/bomber in Britain is one of the most famous examples. Also in Germany the Focke-Wulf Ta-154 night fighter and the Heinkel He-162 jet fighter were constructed entirely of plywood. Bending plywood over curved wing ribs to produce an airfoil is probably not much different from a rib crowned soundboard. Oh, and remember that during the war Steinway was also put to work making wings for the assault gliders used by the Army.

Niles Duncan
Piano rebuilder, Pasadena, CA
www.pianosource.com

Del, this is very interesting.
Trying to put the two together, can the way to crown a laminated soundboard with the way you described in (1) gives you the kind of desirable "system of opposing forces" described in (2) ?

Should I also deduce from (1) that since this only method to crown a laminated board is not tried in production piano, Yamaha claim that their C113T for having a "crowned" and "laminated" soundboard represents a contradiction ?

Thanks.

That is one of their strengths as well Del. Compression crowning won't work because the boards tend to be more stable than a traditional board. This also means less movement with seasonal changes.

I don't see Bosendorfer or Mason & Hamlin ever using them, but Kawai, Yamaha, Samick, and others have done so with varying degrees of success.

Niles,

Didn't the Delignit company start out as a manufacturer of airplane wings?

Yes. My experience (most of it experimental, some practical) with laminated soundboard panels has convinced me that with a reasonable amount of practical R&D pianos with properly designed laminated soundboard panels can be made to sound better than otherwise identical pianos using traditional “solid-spruce” panels (regardless of how they are crowned).

The problem will lie with marketing them, not with designing them or with building them. The fact that historically most manufacturers using laminated soundboard panels have used them ignorantly, if not stupidly, will now work against those wishing to use them appropriately.

No, Yamaha’s claim that their C113T has both a “crowned” and a “laminated” soundboard is not a contradiction. It simply means that they are most likely using a rib-crowned system. This is the most common method of crowning a laminated soundboard assembly.

Del

Yes, that is one of their strengths. But it is not the only one, nor is it the most important. The ability to precisely tailor and control the stiffness/mass characteristic of the panel is the feature that attracted me to the type. Their stability and consistency are just bonuses.

You are probably right in that the traditional manufacturers will never use laminated soundboard panels. This does not mean, however, that we will not see high-end and/or high-performance pianos using them. It wouldn't be the first time traditional manufacturers have been left behind by refusing to investigate and implement new and superior technology.

In my opinion this transition will become inevitable as the world runs out of suitable spruce forests. Or, in the case to the temperate rain forest, forests whose characteristics gave rise to the majestic Sitka spruce from which most of our soundboard tonewood has come. North America is rapidly running out of Sitka spruce and there are no new old-growth forests coming along to renew the supply. Indeed, under the political expedient of "saving them" we’re once again hacking away at what little remains.

Del

Too bad that laminates have a hard time in the market - I for one would love a piano that would be more environmentally stable (and saved a few trees too).

Another example of something being actually better but not acceptable due to tradition.

More than just tradition. Most — though obviously not all — pianos using laminated soundboards to date have been pretty bad. (Does anybody remember the utterly horrible and eminently forgettable “StoryTone?”) For the most part they have been used because some bean counter saw them as a way to save some money and performance be damned. That is not the fault of the technology, it is the fault of ignorance running rampant.

Sooner or later some brave person within some forward looking (or, perhaps, desperate — the quality of spruce around the world is not getting any better) piano manufacturer is going to take another look at these things and see their true potential.

Del

And Yamaha as a major manufacturer today, would be one of the best to lead the way here perhaps.

But if you check on their same website the specs of their U1 piano for example, they specifically point out solid spruce soundboards to be still far superior,i.e "best for amplification of sound, better tone and sustain"

Sounds that nobody in the industry appears to be willing to take this one on.......yet!

norbert

It is regrettable, but you are probably right. We will go into the next evolution of the piano kicking and screaming all the way. To bad. Just think of all the excitement that could be created within the industry by being proactive. And, personally, I think the market figures show that we could use some excitement!

Del

Well, the piano industry has been innovative over the last decade or so, haven't they? I mean, look at all those advanced digital pianos being sold, with all sorts of great features, like string resonance, and recording, and MIDI, and such.

Never mind ... reminds me of a coworker who bought a digital for, wait, 6000$! He could have had a nice upright for that, or a used grand.

Or the other coworker who paid mid thirties for a (crummy) piano, but which happened to have an advanced electronic system built into it. "It's just so convienant around Christmas time to put a disc in ..." Ah well

Dan

Frankly, if Yamaha or any other major maker would really be convinced that they could use laminates instead of the much more expensive solid spruce on their uprights, this without any noticeable tone loss...

......I suspect they would have perhaps long done so by now!!

Including perhaps, most or even all of their uprights of today!

Cost savings, after all, appear to have crept into most of the - at least - smaller models made today; this being supported simply by the fact that the smaller Yamaha pianos of the 60's and 70's [M-series,etc] had never used laminates before.

Are we 'advancing' or - as I suspect - regressing in quality piano making??

norbert :rolleyes:

I don't think the question is loss of tone. I think it is more quality of tone. Laminated boards have different resonance characteristics than solid-wood boards. But I actually grew up with a Story & Clark studio with a laminated mahogany board, and it didn't suffer from being too soft, at least not when I played it.

I should get my sister to clear it off, and stick some new hammers in it. I wore the originals out, pretty much. It would be interesting to see what could be done with it.

A lot depends on how the laminated panel is designed and constructed and on how it is ribbed. You are certainly correct as the laminated panel has been constructed to date. I won't say "designed" because I haven't seen one in production yet that has shown any signs of actually being designed to take advantage of their unique characteristics. But the beauty of the laminated panel is the variety of ways it can be built and tailored to most any specific need or desired performance character.

Del

Not necessarily. There are going to be some formidable marketing hurdles to overcome. It may well be easier to introduce something dramatic at the high end and let it filter down.

Del