2017 was our 20th year online!

Welcome to the Piano World Piano Forums
Over 2.9 million posts about pianos, digital pianos, and all types of keyboard instruments
Join the World's Largest Community of Piano Lovers (it's free)
It's Fun to Play the Piano ... Please Pass It On!

SEARCH
Piano Forums & Piano World
(ad)
Best of Piano Buyer
 Best of Piano Buyer
(ad)
Piano Life Saver - Dampp Chaser
Dampp Chaser Piano Life Saver
Find a Professional
Our Classified Ads
Find Piano Professionals-

*Piano Dealers - Piano Stores
*Piano Tuners
*Piano Teachers
*Piano Movers
*Piano Restorations
*Piano Manufacturers

Advertise on Piano World

Who's Online Now
72 registered members (Beowulf, Coker, Amy H, CyberGene, butchkoch, Craig Hair, clothearednincompo, Animisha, 14 invisible), 307 guests, and 403 spiders.
Key: Admin, Global Mod, Mod
(ad)
Estonia Pianos
Estonia Pianos
Quick Links to Useful Piano & Music Resources
Quick Links:
*Advertise On Piano World
*Free Piano Newsletter
*Online Piano Recitals
*Piano Recitals Index
*Piano & Music Accessories
*Live Piano Venues
*Music School Listings
* Buying a Piano
*Buying A Acoustic Piano
*Buying a Digital Piano
*Pianos for Sale
*Sell Your Piano
*How Old is My Piano?
*Directory/Site Map
*Virtual Piano
*Music Word Search
*Piano Videos
*Virtual Piano Chords & Scales
Previous Thread
Next Thread
Print Thread
Hop To
Page 4 of 11 1 2 3 4 5 6 10 11
Re: "Oilcanning" Soundboard Skeptic [Re: kpembrook] #2920139 12/05/19 10:39 AM
Joined: Sep 2004
Posts: 2,463
G
Gene Nelson Offline
2000 Post Club Member
Offline
2000 Post Club Member
G
Joined: Sep 2004
Posts: 2,463
Originally Posted by kpembrook
Quote
. But what gave the added sustain needed to blend these areas with the rest of the compass was a simple spring placed between rib and board.
So did the spring add stiffness or maybe a very small amount of crown (could not measure any)
But spring back against the force of string bearing happened and I got results.
One interesting bit of info was when I restrung one of the D’s earlier this year - slight crown appeared in the affected area after strings removed. So there was some stiffness and impedance even if lacking power and sustain


I've done the automotive valve spring thing. Seemed to help.

But a compressed spring is a dynamically opposed force -- which is what I said promotes good tone -- rather than some mystical shape in and of itself.


Before I tried the spring I tried (and failed) using powerful rare earth magnets trying to take advantage of their repulsive forces. A fun effort however.


RPT
PTG Member
(ad)
Piano & Music Accessories
piano accessories music gifts tuning and moving equipment
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920143 12/05/19 11:01 AM
Joined: Jun 2011
Posts: 554
C
Craig Hair Online Content
500 Post Club Member
Online Content
500 Post Club Member
C
Joined: Jun 2011
Posts: 554
Hello, we follow these conversations, and Craig Hair was mentioned. And something about the soundboards we re-crown,using "damaged wood" , Hah!...You mean you don't know something. Well I am open to questioning there.???? Yes these old SB's are distorted slightly from when new and now it is super ideal for tone production, "more bang for the buck", and very stable.

Oil can silly talk?. The wood shrinks down in size. A guy near here in Conn. Chris Robinson referred to it as "inverted-crown".
When you UN-string and the bridge is lower than the string plane, it is the (boards getting narrower), often with enough force to tear the ribs apart,"tensile force" collapsing everything. Kaput-ski, And I will say it again, we have never found CRUSHED cells.

Every piano person should have a crown profile tool, like the one in the U Tube "Sound Board walk around 1+2 videos, Very Very useful.
It shows for sure where the curves are, and one must have curves!

Richard Blais.


Craig Hair
Hampshire Piano
Chesterfield, MA
Conservative Piano Restoration
Watch us on YouTube

Is it colder in the winter, or in the country?
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920144 12/05/19 11:06 AM
Joined: Jun 2011
Posts: 554
C
Craig Hair Online Content
500 Post Club Member
Online Content
500 Post Club Member
C
Joined: Jun 2011
Posts: 554
Oh yes about Bruce Hoadley, the wood guy, he knows nothing about old, piano wood. I have had him on the phone about this some years ago now, many years ago.
R Blais.


Craig Hair
Hampshire Piano
Chesterfield, MA
Conservative Piano Restoration
Watch us on YouTube

Is it colder in the winter, or in the country?
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920160 12/05/19 11:46 AM
Joined: Sep 2018
Posts: 647
Chernobieff Piano Offline
500 Post Club Member
Offline
500 Post Club Member
Joined: Sep 2018
Posts: 647
Kudos to McMorrow on the expansion joint reference.
I just watched an engineering video on the subject and it was very educational.

Here's a link: https://www.youtube.com/watch?time_continue=37&v=pH7VfJDq7f4&feature=emb_logo

Of particular interest was the bridge model. With ends free the model moves fore and aft. With the ends fixed, crowning happens. Exactly the same process with soundboards and moisture content. So with a bad install ( soundboard glued in with high moisture content) there was most likely an insufficient expansion joint.
Hence the cracks and the most likely explanation for their cause.
-chris.


Chernobieff Piano Restorations
Lenoir City, Tennessee U.S.A
www.chernobieffpiano.com
grandpianoman@protonmail.com
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920198 12/05/19 01:02 PM
Joined: Sep 2004
Posts: 1,934
R
Roy123 Offline
1000 Post Club Member
Offline
1000 Post Club Member
R
Joined: Sep 2004
Posts: 1,934
Comment 1: I’ll follow with a question: comparing two unloaded but crowned soundboards, both Sitka and ribbed, one compression crowned the other radiused with ribs, which one has more stiffness??"

Comment 2: "When you UN-string and the bridge is lower than the string plane, it is the (boards getting narrower), often with enough force to tear the ribs apart,"tensile force" collapsing everything. Kaput-ski, And I will say it again, we have never found CRUSHED cells."

Comment 3: "I may have an example. A 1927 Vose and Sons Grand came into my shop and it was the earliest example of an RCS soundboard system that I have seen. ... The soundboard had about 8 cracks in it. Since it would be "impossible" to have acquired compression set, then why so many cracks?"

Comment 4: "I have heard several pianos that I was told Del had installed a new board in. I never cared for the sound in the least. Several were Steinway's and they did not sound like what I expect one to sound like. "

Reply to Comment 1: You can't tell, because stiffness varies significantly with rib aspect ratio, thickness, and spacing. One can always dial in various degrees of stiffness by changing various design elements.

Reply to Comment 2: How would you know there weren't crushed cells? To judge that would require examination of various areas of the board under a microscope. One would also need specific knowledge as to how to identify crushed cells. Additionally, compression set may not create violently crushed cells, and therefore the damage may not be readily identifiable to the untrained eye.

Reply to Comment 3: Given that the panel is constrained by the ribs, the possibility of cracking exists as a result of humidity swings. In a RC board, given that the stiffness is not derived from cross-grain stress in the panel, the affect of soundboard cracks should be far less deleterious.

Reply to Comment 4: I don't doubt what you heard, but it's important not to go from the specific from the general, i.e., just because one doesn't like the sound of Del's RC boards doesn't mean other RC boards designed with different parameters might not sound wonderful.

Last edited by Roy123; 12/05/19 01:03 PM.
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920209 12/05/19 01:32 PM
Joined: Jun 2011
Posts: 554
C
Craig Hair Online Content
500 Post Club Member
Online Content
500 Post Club Member
C
Joined: Jun 2011
Posts: 554
That is why the space in between railroad tracks?????, they make louder clickity clacks on cold days.
Man,, this response is a bit much, so much. And yes Vose had very high crown, with ribs shaped round, and they never were considered superior, we have had some of them. They made a medium-inexpensive piano, nothing special.
We find this deformation, "compression set" on the under side, only. When we re-join a panel, they are slightly curved on the bottom, making it difficult to join them, we actually use a gum resin in alcohol treating the wood to deal with this, it is not possible without it, after years of experiments. Expansion co-efficien of steeel is not good example.

R Blais.


Craig Hair
Hampshire Piano
Chesterfield, MA
Conservative Piano Restoration
Watch us on YouTube

Is it colder in the winter, or in the country?
Re: "Oilcanning" Soundboard Skeptic [Re: Roy123] #2920216 12/05/19 01:52 PM
Joined: Sep 2004
Posts: 2,463
G
Gene Nelson Offline
2000 Post Club Member
Offline
2000 Post Club Member
G
Joined: Sep 2004
Posts: 2,463
Originally Posted by Roy123
Comment 1: I’ll follow with a question: comparing two unloaded but crowned soundboards, both Sitka and ribbed, one compression crowned the other radiused with ribs, which one has more stiffness??"

Comment 2: "When you UN-string and the bridge is lower than the string plane, it is the (boards getting narrower), often with enough force to tear the ribs apart,"tensile force" collapsing everything. Kaput-ski, And I will say it again, we have never found CRUSHED cells."

Comment 3: "I may have an example. A 1927 Vose and Sons Grand came into my shop and it was the earliest example of an RCS soundboard system that I have seen. ... The soundboard had about 8 cracks in it. Since it would be "impossible" to have acquired compression set, then why so many cracks?"

Comment 4: "I have heard several pianos that I was told Del had installed a new board in. I never cared for the sound in the least. Several were Steinway's and they did not sound like what I expect one to sound like. "

Reply to Comment 1: You can't tell, because stiffness varies significantly with rib aspect ratio, thickness, and spacing. One can always dial in various degrees of stiffness by changing various design elements.

Reply to Comment 2: How would you know there weren't crushed cells? To judge that would require examination of various areas of the board under a microscope. One would also need specific knowledge as to how to identify crushed cells. Additionally, compression set may not create violently crushed cells, and therefore the damage may not be readily identifiable to the untrained eye.

Reply to Comment 3: Given that the panel is constrained by the ribs, the possibility of cracking exists as a result of humidity swings. In a RC board, given that the stiffness is not derived from cross-grain stress in the panel, the affect of soundboard cracks should be far less deleterious.

Reply to Comment 4: I don't doubt what you heard, but it's important not to go from the specific from the general, i.e., just because one doesn't like the sound of Del's RC boards doesn't mean other RC boards designed with different parameters might not sound wonderful.


Thank you for addressing these and as for #1 I would think the panels described both have the same stiffness and their differences would manifest after they are loaded with the string bearing.
But I can’t prove it.
I was hoping Chris May have an idea using his K constant??


RPT
PTG Member
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920270 12/05/19 05:25 PM
Joined: Sep 2018
Posts: 647
Chernobieff Piano Offline
500 Post Club Member
Offline
500 Post Club Member
Joined: Sep 2018
Posts: 647
I did a study 2 years ago and made a chart of comparison. Using a set of parameters and then using the same on every board and make.

http://forum.pianoworld.com/ubbthre...ndboard-stiffness-study.html#Post2920266

To explain the numbers.

I make my boards at 300, the same K values as the Baldwin L, and a 7' Weber. and a Charles Stieff Upright in which I loved their balance sounds. I went by sound first, and only later learned their stiffness K was identical.

Lower, the boards start having too much of a hollow open sounding bass for me.
Higher, the boards start getting stiffer but at the same time they are adding Mass. The pianos that are over 500 were horrible sounding to me.

Another simple way to measure stiffness is to use frequency. I use a chladni test to find the fundamental frequency of a board. The higher the frequency, the stiffer the board. I'm still collecting data of different boards and their frequencies using Chladni. A couple are on my youtube channel.
-chris


Chernobieff Piano Restorations
Lenoir City, Tennessee U.S.A
www.chernobieffpiano.com
grandpianoman@protonmail.com
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920298 12/05/19 07:40 PM
Joined: Sep 2004
Posts: 2,463
G
Gene Nelson Offline
2000 Post Club Member
Offline
2000 Post Club Member
G
Joined: Sep 2004
Posts: 2,463
Considering and in regard to my question about unloaded soundboards that are crowned different and your K value:
Are you certain you are quantifying stiffness? Especially that Chalandi (sorry if misspelled) test.
For the sake of argument I’d say your capturing more like impedance of the wave, or elasticity times mass?? Maybe I’m splitting hairs.
I still think that both boards have the same stiffness when unloaded.
That is if the materials are the same species.
If I’m right, quantifying stiffness seems very difficult, on paper anyway.


RPT
PTG Member
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920489 12/06/19 08:22 PM
Joined: Dec 2012
Posts: 5,456
E
Ed McMorrow, RPT Offline
5000 Post Club Member
Offline
5000 Post Club Member
E
Joined: Dec 2012
Posts: 5,456
As regards ROY123's response to my experience he notes above as "comment 4":

The expense of trying a method/model that changes the practices I was taught in soundboard making is too much risk for me to bear. And I do more experimenting than most piano makers in design details. I try to choose my battles wisely. Since I have had no problems with the way I make soundboards, and I dislike what I hear in the RC boards I have heard, I find it more productive to solve issues such as string termination problems, duplex noises, longitudinal mode issues, etc.

Roy if course correct, I have not proven my boards are superior, and the RC proponents have not proven their superiority.


In a seemingly infinite universe-infinite human creativity is-seemingly possible.
According to NASA, 93% of the earth like planets possible in the known universe have yet to be formed.
Contact: Ed@LightHammerpiano.com
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920493 12/06/19 08:34 PM
Joined: Dec 2012
Posts: 5,456
E
Ed McMorrow, RPT Offline
5000 Post Club Member
Offline
5000 Post Club Member
E
Joined: Dec 2012
Posts: 5,456
I also find using modeling that explores how L-mode moves from the strings into the structure solves many issues that are recognized as faults by pianists and technicians.

The claims that CC boards are responsible for the "killer" octave problem are not proven at all. I have taken pianos that technicians have claimed have soundboard issues and solved the problems without replacing the board.

These techs were probably influenced by the impedance model Del and others promote. One term missing from the usual presentation of impedance modeling for pianos is the influence of the unison coupling. It changes everything when you understand how this works in pianos.


In a seemingly infinite universe-infinite human creativity is-seemingly possible.
According to NASA, 93% of the earth like planets possible in the known universe have yet to be formed.
Contact: Ed@LightHammerpiano.com
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2920680 12/07/19 12:58 PM
Joined: Sep 2018
Posts: 647
Chernobieff Piano Offline
500 Post Club Member
Offline
500 Post Club Member
Joined: Sep 2018
Posts: 647
I'm pretty confident that I have solved the root cause of the killer octave problem. Other stated causes could be relegated to mitigating factors IMO. Out of 14 Chladni tests performed on different pianos so far, only the Diaphragmatic soundboards of Steinway had the sand go into the middle of the treble section of the bridge. All the other soundboards the sand stopped and never entered the treble section. This means the SS boards are too weak up in the treble section.
Check out my chladni tests on youtube and compare the MHAA to the SSO and see for your selves.
-chris

https://www.youtube.com/watch?v=aFbb1mzhx5E

Last edited by Chernobieff Piano; 12/07/19 01:03 PM.

Chernobieff Piano Restorations
Lenoir City, Tennessee U.S.A
www.chernobieffpiano.com
grandpianoman@protonmail.com
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2921756 12/11/19 12:10 AM
Joined: Sep 2018
Posts: 647
Chernobieff Piano Offline
500 Post Club Member
Offline
500 Post Club Member
Joined: Sep 2018
Posts: 647

Comment 1: I’ll follow with a question: comparing two unloaded but crowned soundboards, both Sitka and ribbed, one compression crowned the other radiused with ribs, which one has more stiffness??"

Reply to Comment 1: You can't tell, because stiffness varies significantly with rib aspect ratio, thickness, and spacing. One can always dial in various degrees of stiffness by changing various design elements.

I think Roy123 is spot on here. Plus Genes question isn't the right question, perhaps even a trick question. Acoustically, I think the real dilemma is weight. For the sake of argument, lets say both have identical stiffness values across the spectrum..Which could easily happen. Compression boards are lighter and offer more real estate in relation to that stiffness value.
But regarding which one has more stiffness? That doesn't matter. What matters is what you are shooting for in the design acoustically. .


Chernobieff Piano Restorations
Lenoir City, Tennessee U.S.A
www.chernobieffpiano.com
grandpianoman@protonmail.com
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2921764 12/11/19 01:09 AM
Joined: Sep 2004
Posts: 2,463
G
Gene Nelson Offline
2000 Post Club Member
Offline
2000 Post Club Member
G
Joined: Sep 2004
Posts: 2,463
The question makes a point: stiffness does not manifest in any way until the soundboard assembly is loaded with string bearing. And challenges anyone to prove otherwise.
Maybe the trick that creeps into mind is the hesitation to quantify stiffness using that K algorithm, you did tie stiffness to pounding an unloaded board and observing sand patterns, no?


RPT
PTG Member
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2921839 12/11/19 08:45 AM
Joined: Sep 2018
Posts: 647
Chernobieff Piano Offline
500 Post Club Member
Offline
500 Post Club Member
Joined: Sep 2018
Posts: 647
Since your boards operate on a loaded/mass principle. Have you tried hardwood rib stock like maple or ash? And if so, what were the tonal differences?


Chernobieff Piano Restorations
Lenoir City, Tennessee U.S.A
www.chernobieffpiano.com
grandpianoman@protonmail.com
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2921895 12/11/19 11:10 AM
Joined: Sep 2004
Posts: 2,463
G
Gene Nelson Offline
2000 Post Club Member
Offline
2000 Post Club Member
G
Joined: Sep 2004
Posts: 2,463
One last try:
Focus.
Two boards of different design, both Sitka and unloaded.
Where is the stiffness?
Can your K algorithm define it or not?


RPT
PTG Member
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2921992 12/11/19 03:04 PM
Joined: Sep 2018
Posts: 647
Chernobieff Piano Offline
500 Post Club Member
Offline
500 Post Club Member
Joined: Sep 2018
Posts: 647
I spent two years on my algorithms that give me a valuable tool . Since it is such an in-depth engineering subject and this is a piano forum, i would confer the same advice you give to others and suggest taking a class to study the subject in detail.


Chernobieff Piano Restorations
Lenoir City, Tennessee U.S.A
www.chernobieffpiano.com
grandpianoman@protonmail.com
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2922079 12/11/19 07:50 PM
Joined: Sep 2004
Posts: 2,463
G
Gene Nelson Offline
2000 Post Club Member
Offline
2000 Post Club Member
G
Joined: Sep 2004
Posts: 2,463
Fair enough - I understand - but I wasn’t asking you to give details about engineering and design algorithm tools, it was a yes or no question.
You did post a link about your algorithm as it applies to an unloaded board and my interpretation was that your not quantifying stiffness it appears to me to be more like wave impedance, sand pattern and resonate frequency.
But I’m ok to leave it at that. This isn’t going anywhere.
I will take that class if it comes my way.


RPT
PTG Member
Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2925175 12/20/19 05:22 PM
Joined: Sep 2004
Posts: 1,934
R
Roy123 Offline
1000 Post Club Member
Offline
1000 Post Club Member
R
Joined: Sep 2004
Posts: 1,934
With all the talk about soundboard stiffness, etc., I thought this simple little spreadsheet might be of interest to some of you.
RibStiffnessCalculator

Re: "Oilcanning" Soundboard Skeptic [Re: UnrightTooner] #2925271 12/21/19 01:22 AM
Joined: Sep 2018
Posts: 647
Chernobieff Piano Offline
500 Post Club Member
Offline
500 Post Club Member
Joined: Sep 2018
Posts: 647
Thats kinda cool. But not very useful. I would equate it to Chess. It's one thing to know how the pieces move, but another thing entirely knowing how they work together.


Chernobieff Piano Restorations
Lenoir City, Tennessee U.S.A
www.chernobieffpiano.com
grandpianoman@protonmail.com
Page 4 of 11 1 2 3 4 5 6 10 11

Moderated by  Piano World 

What's Hot!!
News from the Piano World
Our January 2020 Newsletter Available Online Now...
Free Piano Newsletter
----------------------
Posting Pictures on the Forums
-------------------
Forums RULES & HELP
-------------------
ADVERTISE on Piano World
Shop our Store for Music Lovers!
(ad)
Pianoteq
PianoTeq Bechstein
(ad)
Faust Harrison Pianos
Faust Harrison 100+ Steinway pianos
New Topics - Multiple Forums
Rebuilt Steinways (was)? PFKAS?
by Maestro Lennie - 02/19/20 07:19 AM
Yamaha YDP s52 or Casio CDP 220R
by Love4Music - 02/18/20 09:11 PM
Forum Statistics
Forums41
Topics197,056
Posts2,927,382
Members96,042
Most Online15,252
Mar 21st, 2010
Please Support Our Advertisers


Faust Harrison 100+ Steinways

Dampp Chaser Piano Life Saver

 Best of Piano Buyer

PianoTeq Bechstein
Visit our online store for gifts for music lovers


 
Help keep the forums up and running with a donation, any amount is appreciated!
Or by becoming a Subscribing member! Thank-you.
Donate   Subscribe
 
Our Piano Related Classified Ads
| Dealers | Tuners | Lessons | Movers | Restorations | Pianos For Sale | Sell Your Piano |

Advertise on Piano World
| Subscribe | Piano World | PianoSupplies.com | Advertise on Piano World |
| |Contact | Privacy | Legal | About Us | Site Map | Free Newsletter |


copyright 1997 - 2019 Piano World ® all rights reserved
No part of this site may be reproduced without prior written permission
Powered by UBB.threads™ PHP Forum Software 7.7.3