Welcome to the Piano World Piano Forums
Over 2.5 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
What's Hot!!
Posting Pictures on the Forums
-------------------
Forums RULES & HELP
-------------------
ADVERTISE on Piano World
(125ad)
Piano Life Saver - Dampp Chaser
Dampp Chaser Piano Life Saver
(ad)
Piano Buyer Guide
Piano Buyer Fall 2017
Who's Online Now
95 registered members (briangmoore, accordeur, 36251, Alex Hutor, Anita Potter, 27 invisible), 1,825 guests, and 2 spiders.
Key: Admin, Global Mod, Mod
(ad)
Estonia Pianos
Estonia Pianos
Quick Links to Useful Piano & Music Resources
Our Classified Ads
Find Piano Professionals-

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

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
Page 1 of 2 1 2
#1412742 - 04/07/10 04:13 AM Stone Tone (Granite) piano bridge?  
Joined: Jan 2009
Posts: 3,489
beethoven986 Offline
3000 Post Club Member
beethoven986  Offline
3000 Post Club Member

Joined: Jan 2009
Posts: 3,489
http://www.youtube.com/watch?v=J6G_FbD3q-Q

I'm curious to hear what you all think about this. Anyone seen/ heard of this before?

(ad)
Piano & Music Accessories
piano accessories music gifts tuning and moving equipment
#1412791 - 04/07/10 08:14 AM Re: Stone Tone (Granite) piano bridge? [Re: beethoven986]  
Joined: Feb 2005
Posts: 3,295
Steve Chandler Offline
3000 Post Club Member
Steve Chandler  Offline
3000 Post Club Member

Joined: Feb 2005
Posts: 3,295
Urbandale, Iowa
Well the first thing I notice is they've got two microphones on the granite bridge piano, but use the camcorder mic for the other. So the pianos may be identical (except the bridge) but the recording apparatus isn't. From this video it is therefore impossible to discern the cause of the obvious sonic difference between the two.

#1412877 - 04/07/10 11:06 AM Re: Stone Tone (Granite) piano bridge? [Re: Steve Chandler]  
Joined: Oct 2009
Posts: 446
JD Grandt Offline
Full Member
JD Grandt  Offline
Full Member

Joined: Oct 2009
Posts: 446
Richmond Hill, Ontario
I don't want to knock it because there does seem to be a noticeable outcome with the granite bridge, but there are too many flaws (unless new information is provided) with the overall comparison.

First their is so such thing as two identical 88 and 100 year old pianos, no matter what the brand (these are from 1922 and 1905 it says). The soundboards could be in night and day conditions depending on the environment each piano 'grew up' in.

The microphones used are also interesting why one has them the other doesn't - I would guess that although they are there (on the stonebridge mid and upper treble) I hope they are not actually being used in the demo.

Then you get into hammer voicing which can again, night and day, make a difference in the overall tone and sustain you get out of a piano.

I never heard about a granite bridge but it is worthy of learning more.


John
J.D. Grandt Piano Supply Company
www.jdgrandt.com
https://www.facebook.com/JDGrandtPianoSupplyCo
J.D. Grandt (Worldwide)
Steingraeber & Söhne (Canada)
Lomence Modern Crystal Piano (North America)
Piano Bass String Manufacturing Specialist (Worldwide)
#1412948 - 04/07/10 12:58 PM Re: Stone Tone (Granite) piano bridge? [Re: JD Grandt]  
Joined: May 2001
Posts: 22,761
pianoloverus Online content
Yikes! 10000 Post Club Member
pianoloverus  Online Content
Yikes! 10000 Post Club Member

Joined: May 2001
Posts: 22,761
New York City
I have never heard any piano before the Stonetone bridge example where the higher notes in a chord didn't die out significantly before the lower ones. So I'm not sure that even comparing it to another piano of the same make/model is so critical in order to realize the piano has IMO a much smaller decay and longer sustain than most pianos.

Last edited by pianoloverus; 04/07/10 03:28 PM.
(ad ) MusicNotes.com
sheet music search
#1412997 - 04/07/10 02:07 PM Re: Stone Tone (Granite) piano bridge? [Re: pianoloverus]  
Joined: Aug 2006
Posts: 1,689
Robert 45 Offline
1000 Post Club Member
Robert 45  Offline
1000 Post Club Member

Joined: Aug 2006
Posts: 1,689
Auckland New Zealand
This is very interesting, but there are too many variables to draw a definite conclusion.
Obviously the "miking" of the two pianos is different and the piano themselves are not identical because of their differing age.
The piano player even played the "stone bridge" piano better than the other one.
However, I agree that the so called "granite bridge" instrument does sound beautiful. That could be because of its board.

Thank you Beethoven986,
Robert.

#1413033 - 04/07/10 02:46 PM Re: Stone Tone (Granite) piano bridge? [Re: Robert 45]  
Joined: Jan 2003
Posts: 19,862
apple* Offline
apple*  Offline


Joined: Jan 2003
Posts: 19,862
Kansas
how very interesting.. i love big Baldwins anyway.


accompanist/organist.. a non-MTNA teacher to a few

love and peace, Õun (apple in Estonian)
#1413089 - 04/07/10 03:41 PM Re: Stone Tone (Granite) piano bridge? [Re: apple*]  
Joined: Sep 2004
Posts: 1,821
Roy123 Offline
1000 Post Club Member
Roy123  Offline
1000 Post Club Member

Joined: Sep 2004
Posts: 1,821
Massachusetts
One thing is for sure, the bridge will be quite a bit heavier. Is this a good thing? Maybe, maybe not.

#1413137 - 04/07/10 04:26 PM Re: Stone Tone (Granite) piano bridge? [Re: Roy123]  
Joined: Jun 2003
Posts: 25,535
BDB Offline
Yikes! 10000 Post Club Member
BDB  Offline
Yikes! 10000 Post Club Member

Joined: Jun 2003
Posts: 25,535
Oakland
It looks like the "wooden bridge" piano looks like it has the original strings, while the "granite bridge" piano does not. That could account for the difference in the sound.


Semipro Tech
#1413172 - 04/07/10 04:58 PM Re: Stone Tone (Granite) piano bridge? [Re: BDB]  
Joined: Mar 2005
Posts: 2,726
Grandpianoman Offline
2000 Post Club Member
Grandpianoman  Offline
2000 Post Club Member

Joined: Mar 2005
Posts: 2,726
Portland, Oregon
If that type of sustain and tone is due solely because of this 'granite' bridge, it's very impressive. It reminds me of the the Stuart&Sons pianos I have heard online.

This technology seems similar to the Wapin bridge system and the Steingraber/Phoenix bridge system, in that it is trying to improve the termination of the strings to the soundboard.

One thing I did notice, and I am not sure if was because of the mics used and the very live acoustics of the room, but the high treble, 5,6, and 7th octaves seemed overly bright and somewhat too intense in the granite bridge piano. I wonder how that would sound in a normal size living room.

In any case, it's something I would like to hear in person!

#1413259 - 04/07/10 07:31 PM Re: Stone Tone (Granite) piano bridge? [Re: Grandpianoman]  
Joined: Sep 2006
Posts: 3,919
Supply Offline
3000 Post Club Member
Supply  Offline
3000 Post Club Member

Joined: Sep 2006
Posts: 3,919
Vancouver Island, BC, Canada
I watched the first segment without the sound. The body language is highly suggestive. The player disparagingly dismisses the original piano with a wave of his hand. Then he sits down and hardly touches the keys of the enhanced piano before he jerks his hands up to his face in disbelief in an exaggerated fashion and as if he has never heard the instrument before (after all, it is only a piano). Bad acting.

Not to say there isn't an effect, but it is hardly a double blind test. To be fair, it is not presented as such. At the same time, the merits, if there are some, should be allowed to speak for themselves. For me obvious sales pitch casts a suspicion on the whole thing. Born a skeptic, I guess...

#1413357 - 04/07/10 11:18 PM Re: Stone Tone (Granite) piano bridge? [Re: Supply]  
Joined: Mar 2003
Posts: 3,778
Keith D Kerman Online content
3000 Post Club Member
Keith D Kerman  Online Content
3000 Post Club Member

Joined: Mar 2003
Posts: 3,778
Gaithersburg, MD (Washington D...
Originally Posted by Supply
I watched the first segment without the sound. The body language is highly suggestive. The player disparagingly dismisses the original piano with a wave of his hand. Then he sits down and hardly touches the keys of the enhanced piano before he jerks his hands up to his face in disbelief in an exaggerated fashion and as if he has never heard the instrument before (after all, it is only a piano). Bad acting.

Not to say there isn't an effect, but it is hardly a double blind test. To be fair, it is not presented as such. At the same time, the merits, if there are some, should be allowed to speak for themselves. For me obvious sales pitch casts a suspicion on the whole thing. Born a skeptic, I guess...


Totally agree. Whatever the merits of this bridge are, it is clear that this presentation is a total transparent contrivance that is highly slanted.


Keith D Kerman
PianoCraft
Rebuilding & Sales - vintage and used Steinway, Mason & Hamlin
New Steingraeber, Estonia, Baldwin
www.pianocraft.net
check out www.sitkadoc.com
www.twitter.com/pianocraft https://www.youtube.com/user/pianocraftchannel

keith@pianocraft.net 888-840-5460
#1413360 - 04/07/10 11:36 PM Re: Stone Tone (Granite) piano bridge? [Re: Supply]  
Joined: Sep 2008
Posts: 8,453
Horowitzian Offline
8000 Post Club Member
Horowitzian  Offline
8000 Post Club Member

Joined: Sep 2008
Posts: 8,453
Originally Posted by Supply
I watched the first segment without the sound. The body language is highly suggestive. The player disparagingly dismisses the original piano with a wave of his hand. Then he sits down and hardly touches the keys of the enhanced piano before he jerks his hands up to his face in disbelief in an exaggerated fashion and as if he has never heard the instrument before (after all, it is only a piano). Bad acting.

Not to say there isn't an effect, but it is hardly a double blind test. To be fair, it is not presented as such. At the same time, the merits, if there are some, should be allowed to speak for themselves. For me obvious sales pitch casts a suspicion on the whole thing. Born a skeptic, I guess...


Agreed. This video was a complete waste of time.


Close only counts in horseshoes, hand grenades, and nuclear weapons.
#1413416 - 04/08/10 04:14 AM Re: Stone Tone (Granite) piano bridge? [Re: Roy123]  
Joined: Jul 2009
Posts: 2,265
Mark R. Offline
2000 Post Club Member
Mark R.  Offline
2000 Post Club Member

Joined: Jul 2009
Posts: 2,265
Pretoria, South Africa
Originally Posted by Roy123
One thing is for sure, the bridge will be quite a bit heavier.


Sure it will, but would this difference be significant compared to the downbearing forces that are present in any piano?


Autodidact interested in piano technology.
LinkedIn profile
1922 49" Zimmermann, project piano.
1970 44" Ibach, daily music maker.
#1413418 - 04/08/10 04:52 AM Re: Stone Tone (Granite) piano bridge? [Re: Mark R.]  
Joined: Oct 2008
Posts: 715
Bart Kinlein Offline
500 Post Club Member
Bart Kinlein  Offline
500 Post Club Member

Joined: Oct 2008
Posts: 715
Maryland
I agree about the pre-conceived attitide of the performer.

It would be interesting if they were to invite a member of this forum to audition the pianos. A less biased opinion would be welcome. But even so, as has been pointed out, the two pianos are not "identical" except for the bridge.

Interesting, nevertheless.


Steinway 1905 model A, rebuild started 2008, completed 2012
Yahama CVP-401
Will somone get my wife off the Steinway so I can play it!
#1413559 - 04/08/10 11:55 AM Re: Stone Tone (Granite) piano bridge? [Re: Mark R.]  
Joined: Sep 2004
Posts: 1,821
Roy123 Offline
1000 Post Club Member
Roy123  Offline
1000 Post Club Member

Joined: Sep 2004
Posts: 1,821
Massachusetts
Originally Posted by Mark R.
Originally Posted by Roy123
One thing is for sure, the bridge will be quite a bit heavier.


Sure it will, but would this difference be significant compared to the downbearing forces that are present in any piano?


The issue isn't downbearing force, it's the impedance of the soundboard system as seen by the string. Both the mass and stiffness of the soundboard strongly affect the string/soundboard response.

#1413568 - 04/08/10 12:06 PM Re: Stone Tone (Granite) piano bridge? [Re: Roy123]  
Joined: Mar 2003
Posts: 3,778
Keith D Kerman Online content
3000 Post Club Member
Keith D Kerman  Online Content
3000 Post Club Member

Joined: Mar 2003
Posts: 3,778
Gaithersburg, MD (Washington D...
Originally Posted by Roy123
Originally Posted by Mark R.
Originally Posted by Roy123
One thing is for sure, the bridge will be quite a bit heavier.


Sure it will, but would this difference be significant compared to the downbearing forces that are present in any piano?


The issue isn't downbearing force, it's the impedance of the soundboard system as seen by the string. Both the mass and stiffness of the soundboard strongly affect the string/soundboard response.


The extra mass will increase the impedance and may increase the sustain at the expense of the attack becoming increasingly percussive. Depending on the piano, this may be a help or a disaster.


Keith D Kerman
PianoCraft
Rebuilding & Sales - vintage and used Steinway, Mason & Hamlin
New Steingraeber, Estonia, Baldwin
www.pianocraft.net
check out www.sitkadoc.com
www.twitter.com/pianocraft https://www.youtube.com/user/pianocraftchannel

keith@pianocraft.net 888-840-5460
#1419415 - 04/18/10 10:48 AM Re: Stone Tone (Granite) piano bridge? [Re: Keith D Kerman]  
Joined: Apr 2010
Posts: 92
Robert Di Santo Offline
Full Member
Robert Di Santo  Offline
Full Member

Joined: Apr 2010
Posts: 92
United States
Hello everyone, My Names Robert B. Di Santo and I am the inventor / owner / engineer of all stonetone technologies.
My piano tech Daniel Koehler owner of naplespiano.com has worked with me from our first prototype.
I see that he has posted just a couple videos on you tube... since we have proved our theories with an old dilapidated piano and brought it back from the dead to be better than new besides out performing anything thats been put side by side as a comparison.
Today I am limited on time to respond but all inquires associated with this thread can be answered if you email or call Dan himself to ask how what and why this is so cutting edge. He would be glad to answer all of your questions.

Anyone who wants to hear the piano next to a stock piano no matter the brand or size you can email Dan @ www.naplespiano.com or call him directly 239.404.8007 Naples florida.

or email me @ stonetonemusic@aol.com or myspace.com/stonetonemusicinc

Have a great day.
Bye now


Robert B. Di Santo
StoneTone®
Music of the earth®
#1419428 - 04/18/10 11:19 AM Re: Stone Tone (Granite) piano bridge? [Re: Robert Di Santo]  
Joined: Apr 2010
Posts: 92
Robert Di Santo Offline
Full Member
Robert Di Santo  Offline
Full Member

Joined: Apr 2010
Posts: 92
United States
http://www.youtube.com/watch?v=CDTL7CYgArU
http://www.youtube.com/watch?v=idbaPu1gDPg&feature=email

Here are 2 different players and 2 different pianos performing the same piece, the first is Richard Bosworth performing on our Stonetone enhanced 6' 3" Baldwin the other is a stock piano.

Enjoy


Robert B. Di Santo
StoneTone®
Music of the earth®
#1419445 - 04/18/10 11:46 AM Re: Stone Tone (Granite) piano bridge? [Re: Robert Di Santo]  
Joined: Mar 2003
Posts: 3,778
Keith D Kerman Online content
3000 Post Club Member
Keith D Kerman  Online Content
3000 Post Club Member

Joined: Mar 2003
Posts: 3,778
Gaithersburg, MD (Washington D...
Hi Robert,

Good luck with your project. I noticed this quote made 3 days ago with the first video:

Naplespiano: "I have heard many same pieces on the others out there and this is the clearest I have ever heard. Congratulations on your performance and piano with the cleanest sound I have ever heard in the world. Love the pictures and it follows the music well. excellent job. I look forward to more piece by you." Dan

Seems staged, which was the criticism of the marketing of your product earlier in the thread. Maybe let the product speak more for itself and let people not involved with it make the comments, or if they are involved with it, they should identify themselves as such.

This is not a comment on the product itself. Obviously, this is just my observation which is worth double its cost!

Oh yeah, that Rubinstein recording is nice, but Horowitz owns that Mazurka
http://www.youtube.com/watch?v=mtHMtLoWudc&feature=related

Last edited by Keith D Kerman; 04/18/10 11:52 AM.

Keith D Kerman
PianoCraft
Rebuilding & Sales - vintage and used Steinway, Mason & Hamlin
New Steingraeber, Estonia, Baldwin
www.pianocraft.net
check out www.sitkadoc.com
www.twitter.com/pianocraft https://www.youtube.com/user/pianocraftchannel

keith@pianocraft.net 888-840-5460
#1419465 - 04/18/10 12:48 PM Re: Stone Tone (Granite) piano bridge? [Re: Robert Di Santo]  
Joined: Jun 2003
Posts: 25,535
BDB Offline
Yikes! 10000 Post Club Member
BDB  Offline
Yikes! 10000 Post Club Member

Joined: Jun 2003
Posts: 25,535
Oakland
Originally Posted by Robert Di Santo
http://www.youtube.com/watch?v=CDTL7CYgArU
http://www.youtube.com/watch?v=idbaPu1gDPg&feature=email

Here are 2 different players and 2 different pianos performing the same piece, the first is Richard Bosworth performing on our Stonetone enhanced 6' 3" Baldwin the other is a stock piano.

Enjoy


Why do you need to tell us which is which? If the results are so different, it should be obvious.


Semipro Tech
#1420041 - 04/19/10 12:56 PM Re: Stone Tone (Granite) piano bridge? [Re: BDB]  
Joined: Apr 2010
Posts: 92
Robert Di Santo Offline
Full Member
Robert Di Santo  Offline
Full Member

Joined: Apr 2010
Posts: 92
United States
F. Y. I. What else? Thats why. ENJOY because this Technology I've developed will change the face of pianos forever, and enable all artists to write new piano composition you couldn't do on ANY other acoustic piano no matter the variables, soon I will post the out come of several more pianos that are within a few moths of completion so when the Baldwin 9 foot concert grand roars, that will send the bar of performance thru the roof..

Keep in mind these pianos I'm retrofitting only concludes my reasearch coinsiding with my patents I currently hold but I have certain manufactures that already have shown intrest to create a series of stonetone lines when I haven't even heard the outcome of the new pianos I'm working on now that have soundboards with a full crown and brand new....So I can't wait to hear them myself !! Life is great , Be creative in life it's healthy for the soul laugh

Have a great day


We'll see, 2010's a benchmark for Stonetone to go public after all the R & D


Robert B. Di Santo
StoneTone®
Music of the earth®
#1423846 - 04/25/10 08:59 AM Re: Stone Tone (Granite) piano bridge? [Re: Keith D Kerman]  
Joined: Apr 2010
Posts: 92
Robert Di Santo Offline
Full Member
Robert Di Santo  Offline
Full Member

Joined: Apr 2010
Posts: 92
United States
Keith, Thank you for your valuable input, That video was done on a moments notice since we had access to an identical Baldwin as ours with exception of the age difference varying less than 20 years apart, even tho the mics were't the same and so on.

The video served us well for what it was used for but since then our approach on how to make as close a comparison Richard Bosworth suggested to make comparisons like the chopin clips I posted, critics and the like will have something to say no matter whats done, If anyone is close to Naples Florida come listen for yourself. Any day or time would be fine by us.

Thanks again Keith,
Robert Di Santo


Robert B. Di Santo
StoneTone®
Music of the earth®
#1423926 - 04/25/10 11:39 AM Re: Stone Tone (Granite) piano bridge? [Re: Robert Di Santo]  
Joined: Mar 2005
Posts: 2,726
Grandpianoman Offline
2000 Post Club Member
Grandpianoman  Offline
2000 Post Club Member

Joined: Mar 2005
Posts: 2,726
Portland, Oregon
Robert, thanks for posting these examples. I enjoyed the sustain and tone of your Stonetone piano.

The results are VERY OBVIOUS to anyone with ANY kind of musical ear. One can hear the difference between your granite-bridge piano and the normal piano, different pianists, recording venues and techniques notwithstanding.

I look forward to hearing more about your invention! Continued success!!


#1424038 - 04/25/10 04:11 PM Re: Stone Tone (Granite) piano bridge? [Re: Robert Di Santo]  
Joined: Sep 2004
Posts: 1,821
Roy123 Offline
1000 Post Club Member
Roy123  Offline
1000 Post Club Member

Joined: Sep 2004
Posts: 1,821
Massachusetts
Originally Posted by Robert Di Santo
Keep in mind these pianos I'm retrofitting only concludes my reasearch coinsiding with my patents I currently hold but



A search of the US Patent Office database shows no patents issued to anyone named Robert Di Santo or Robert DiSanto. Have these patents not been issued, or were they submitted under a different name?

#1424043 - 04/25/10 04:32 PM Re: Stone Tone (Granite) piano bridge? [Re: Roy123]  
Joined: Sep 2004
Posts: 1,821
Roy123 Offline
1000 Post Club Member
Roy123  Offline
1000 Post Club Member

Joined: Sep 2004
Posts: 1,821
Massachusetts
Granite's hardness varies depending on its composition, but is roughly equivalent to that of steel, whose hardness also varies depending on composition. Granite's density is about the same as aluminum, though it's modulus is somewhat less, meaning that aluminum provides greater stiffness. A wooden or aluminum bridge capped with steel agraffes should be able to provide the same mass and hardness at the string termination as a granite bridge. I wouldn't expect one or the other to provide very different tone. Of course, various design elements other than mass, stiffness, and hardness can affect the string termination.

Aluminum and steel are much easier to form and machine, so I would expect that they would provide more options for string termination than would granite. On the other hand granite sounds so exotic.

#1424794 - 04/26/10 08:17 PM Re: Stone Tone (Granite) piano bridge? [Re: Roy123]  
Joined: Feb 2002
Posts: 1,338
KawaiDon Offline
1000 Post Club Member
KawaiDon  Offline
1000 Post Club Member

Joined: Feb 2002
Posts: 1,338
Orange County, CA
Roy,

Keep in mind that they are making the entire bridge from granite, not just the cap. It is very massive and stiff. It appears that they are using very fine grain black granite, often used as decorative surfaces and counter tops and such.

I'll be interested to hear a better recording at some point of this bridge design on a newer / better piano.

Don Mannino RPT

#1424984 - 04/27/10 06:34 AM Re: Stone Tone (Granite) piano bridge? [Re: KawaiDon]  
Joined: Sep 2004
Posts: 1,821
Roy123 Offline
1000 Post Club Member
Roy123  Offline
1000 Post Club Member

Joined: Sep 2004
Posts: 1,821
Massachusetts
Originally Posted by KawaiDon
Roy,

Keep in mind that they are making the entire bridge from granite, not just the cap. It is very massive and stiff. It appears that they are using very fine grain black granite, often used as decorative surfaces and counter tops and such.

I'll be interested to hear a better recording at some point of this bridge design on a newer / better piano.

Don Mannino RPT


Hi Don,

I understand that, and my comments apply to that case. Consider that a string bears against a bridge over a tiny area. If that bearing point is against, let's say, a steel agraffe, the agraffe can then spread the force of the string over a much larger area, at which point the agraffe could then bear against aluminum or a hard wood. Remember that the Young's modulus of granite is not higher than aluminum. If a large mass is one's goal, the steel agraffe could bear against a brass or bronze bridge, both of which are denser than granite and have a higher Young's modulus than granite.

The purpose of my post was to point out that granite isn't really that special. Additionally, it is brittle and hard to work with. I would be surprised if very heavy bridges were somehow just what was needed for improved tone, but even if that's the case, I think there are more suitable materials to use than stone.

Last edited by Roy123; 04/27/10 06:35 AM.
#1424992 - 04/27/10 06:52 AM Re: Stone Tone (Granite) piano bridge? [Re: Roy123]  
Joined: Jul 2003
Posts: 314
mikewu99 Offline
Full Member
mikewu99  Offline
Full Member

Joined: Jul 2003
Posts: 314
Audubon, PA
Originally Posted by Roy123
Originally Posted by Robert Di Santo
Keep in mind these pianos I'm retrofitting only concludes my reasearch coinsiding with my patents I currently hold but



A search of the US Patent Office database shows no patents issued to anyone named Robert Di Santo or Robert DiSanto. Have these patents not been issued, or were they submitted under a different name?
You needed to search the application database:

PIANO HAVING DENSE SOUND-ENHANCING COMPONENT

and

AUDIO DEVICE HAVING DENSE SOUND ENHANCING COMPONENT

#1425085 - 04/27/10 10:10 AM Re: Stone Tone (Granite) piano bridge? [Re: mikewu99]  
Joined: Dec 2005
Posts: 3,458
Cy Shuster, RPT Offline
3000 Post Club Member
Cy Shuster, RPT  Offline
3000 Post Club Member

Joined: Dec 2005
Posts: 3,458
Albuquerque, NM
I wonder how you keep a granite bridge attached to a soundboard, as a grand bounces on its side in a truck? Can you attach screws through the soundboard?

Since impedance matching is important to prevent energy loss, wouldn't there be a nonlinear effect with a very dense material along its whole length? Manufacturers like Baldwin have attached weights to the bass to improve response, but wouldn't it be counterproductive in the treble? Is it both bridges, or just the bass?

--Cy--


Cy Shuster, RPT
www.shusterpiano.com
Albuquerque, New Mexico
Director, PTG Norfolk 2016 Technical Institute
http://convention.ptg.org
#1425318 - 04/27/10 02:44 PM Re: Stone Tone (Granite) piano bridge? [Re: Cy Shuster, RPT]  
Joined: Sep 2004
Posts: 1,821
Roy123 Offline
1000 Post Club Member
Roy123  Offline
1000 Post Club Member

Joined: Sep 2004
Posts: 1,821
Massachusetts
Originally Posted by Cy Shuster
I wonder how you keep a granite bridge attached to a soundboard, as a grand bounces on its side in a truck? Can you attach screws through the soundboard?

Since impedance matching is important to prevent energy loss, wouldn't there be a nonlinear effect with a very dense material along its whole length? Manufacturers like Baldwin have attached weights to the bass to improve response, but wouldn't it be counterproductive in the treble? Is it both bridges, or just the bass?

--Cy--


The patent application shows screws. To be able to screw into granite, you typically make a hole and then embed a metal threaded insert.

Adding mass does not cause a nonlinear effect, but your point is a good one--additional mass may be helpful in some areas of the scale and not in others. Given that any number of people have experimented with adding mass by using it in selected areas of the bridge, it seems unlikely to me that adding mass everywhere would be desirable.

Many people have also experimented with adjusting the stiffness of the soundboard, so using a stone bridge to make it stiffer everywhere also seems unlikely to be universally applicable.

Another possible issue is the fragility of granite. Like many types of stone, it is strong in compression, but weak in tension. That's why granite can be cracked into blocks quite easily during the quarrying process. A long thin piece of granite such as a piano bridge would be very easily cracked.

As you've noticed, I'm skeptical of the idea, but the proof is in the performance, so final judgment must be reserved until further testing is done.

Page 1 of 2 1 2

Moderated by  Ken Knapp, Piano World 

Piano Acc. & Gift Items in
Piano World's Online Store
In PianoSupplies.com ,(a division of Piano World)
our online store for piano and music gifts and accessories, Digital Piano Dolly, party goods, tuning equipment, piano moving equipment, benches, lamps Caster Cups and more.


Free Shipping* on Jansen Artist Piano Benches, Cocoweb Piano Lamps, Hidrau Hydraulic Piano Benches
(*free shipping within contiguous U.S. only)
(ad)
Pearl River & Ritmuller
Pearl River Pianos
(ad)
Pianoteq
PianoTeq 6 Out now
ad
Pierce Piano Atlas


New Topics - Multiple Forums
Pianoteq 6 Recording Function Glitch
by newbert. 11/18/17 04:10 PM
collapsing pinky
by Muove. 11/18/17 02:22 PM
DP-10X built in speakers for Pianoteq?
by Tim1981. 11/18/17 12:16 PM
Kawai K3 damper felts for "F" look different
by Crow Wing. 11/18/17 10:09 AM
Scarlatti Sonata B minor k 27 pedal
by Potlea. 11/18/17 05:46 AM
Forum Statistics
Forums44
Topics182,829
Posts2,672,802
Members89,158
Most Online15,252
Mar 21st, 2010
(ad)
Accu-Tuner
Sanderson Accu-Tuner
Check It Out!
There's a lot more to Piano World than just the forums.
Click Here to
Explore The Rest of Piano World!!
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 - 2017 Piano World ® all rights reserved
No part of this site may be reproduced without prior written permission
Powered by UBB.threads™ PHP Forum Software 7.6.0