Pianotech

In the book by Keith Hill called "Treatise on the True Art of Making Musical Instruments, A Practical Guide to the Hidden Craft of Enhancing Sound" (Yes, That's the whole Title)
The author discusses Membrane Driving Points and offers a diagram. He explains that the driving points are in musical ratios. He later explains how past makers put the bridges on those locations. For me, the author doesn't explain how those positions are found. Can anyone figure it out?
(see pics)
Thanks


------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------

I don't think is has much to do with the membrane at all. The musical ratio, is defined by how long a particular frequency's speaking length has to be relative given the breaking load of the wire you are using. In the treble sections there is not much room to mess with shape much, which is why a D has pretty similar treble shape to a 5 ft piano. The treble shape of the bridge is really determined for us by the physical parameters of each note's frequency and wire being used. As the scale descends from the treble, one can mess with the lengths some, but only in a way that compromises bp% numbers, if wraps are not part of the mix. There is more messing allowed in a scale using wrapped strings,  depending on where the bass break is chosen to be, but really, in a plain wire scale, the wire you are using determines length.

I have played with the numbers, to see if I could change bridge shape. Doing this, one quickly sees, especially in the two treble sections,  that the shape of the bridge is not terribly negotiable, and is determined by the frequency and breaking point numbers. I suppose you can choose to move the front termination to effect bridge shape, but given strike point rations, that number as well, is not negotiable much either. In the treble, there is none to very little negotiability, and in the tenor some but not much.

In wrapped sections, there is more length negotiation available, but, from the look of this dude's drawings, I'm not thinking any wraps are on offer anyway, so that negotiability comes off the table.


------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026
------------------------------

Original Message:
Sent: 12-01-2019 11:49
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

In the book by Keith Hill called "Treatise on the True Art of Making Musical Instruments, A Practical Guide to the Hidden Craft of Enhancing Sound" (Yes, That's the whole Title)
The author discusses Membrane Driving Points and offers a diagram. He explains that the driving points are in musical ratios. He later explains how past makers put the bridges on those locations. For me, the author doesn't explain how those positions are found. Can anyone figure it out?
(see pics)
Thanks

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------

Sure, the bridge shape may not be that negotiable, but the bridge location on the piano certainly is via case shape, cut off bar, etc. I'm not sure how he is calculating the ratios.

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------

Original Message:
Sent: 12-01-2019 16:37
From: Jim Ialeggio
Subject: Membrane Driving Point Ratio Help

I don't think is has much to do with the membrane at all. The musical ratio, is defined by how long a particular frequency's speaking length has to be relative given the breaking load of the wire you are using. In the treble sections there is not much room to mess with shape much, which is why a D has pretty similar treble shape to a 5 ft piano. The treble shape of the bridge is really determined for us by the physical parameters of each note's frequency and wire being used. As the scale descends from the treble, one can mess with the lengths some, but only in a way that compromises bp% numbers, if wraps are not part of the mix. There is more messing allowed in a scale using wrapped strings,  depending on where the bass break is chosen to be, but really, in a plain wire scale, the wire you are using determines length.

I have played with the numbers, to see if I could change bridge shape. Doing this, one quickly sees, especially in the two treble sections,  that the shape of the bridge is not terribly negotiable, and is determined by the frequency and breaking point numbers. I suppose you can choose to move the front termination to effect bridge shape, but given strike point rations, that number as well, is not negotiable much either. In the treble, there is none to very little negotiability, and in the tenor some but not much.

In wrapped sections, there is more length negotiation available, but, from the look of this dude's drawings, I'm not thinking any wraps are on offer anyway, so that negotiability comes off the table.


------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 12-01-2019 11:49
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

In the book by Keith Hill called "Treatise on the True Art of Making Musical Instruments, A Practical Guide to the Hidden Craft of Enhancing Sound" (Yes, That's the whole Title)
The author discusses Membrane Driving Points and offers a diagram. He explains that the driving points are in musical ratios. He later explains how past makers put the bridges on those locations. For me, the author doesn't explain how those positions are found. Can anyone figure it out?
(see pics)
Thanks

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------

I'll take a guess.
It looks like the author is making a geometry problem out of it.
First, Find the exact center (centroid) of the soundboard.  For the triangular shape he is showing from what is probably a harpsichord, it wouldn't be difficult to find.
Second, measure out from the centroid to each of the three sides with a perpendicular line.  
Third, Divide these lines into 6 segments.
The points then create the nested triangles he is showing in the diagram (except the innermost triangle which is omitted)
That's how I interpret his diagram.  Whether it produces a better sounding instrument or not I have no idea.

------------------------------
Walter Bagnall RPT
[Better Music Piano Tuning]
Chillicothe OH
[www.bettermusicpianotuning.com]
------------------------------

Original Message:
Sent: 12-01-2019 16:57
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

Sure, the bridge shape may not be that negotiable, but the bridge location on the piano certainly is via case shape, cut off bar, etc. I'm not sure how he is calculating the ratios.

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720

Original Message:
Sent: 12-01-2019 16:37
From: Jim Ialeggio
Subject: Membrane Driving Point Ratio Help

I don't think is has much to do with the membrane at all. The musical ratio, is defined by how long a particular frequency's speaking length has to be relative given the breaking load of the wire you are using. In the treble sections there is not much room to mess with shape much, which is why a D has pretty similar treble shape to a 5 ft piano. The treble shape of the bridge is really determined for us by the physical parameters of each note's frequency and wire being used. As the scale descends from the treble, one can mess with the lengths some, but only in a way that compromises bp% numbers, if wraps are not part of the mix. There is more messing allowed in a scale using wrapped strings,  depending on where the bass break is chosen to be, but really, in a plain wire scale, the wire you are using determines length.

I have played with the numbers, to see if I could change bridge shape. Doing this, one quickly sees, especially in the two treble sections,  that the shape of the bridge is not terribly negotiable, and is determined by the frequency and breaking point numbers. I suppose you can choose to move the front termination to effect bridge shape, but given strike point rations, that number as well, is not negotiable much either. In the treble, there is none to very little negotiability, and in the tenor some but not much.

In wrapped sections, there is more length negotiation available, but, from the look of this dude's drawings, I'm not thinking any wraps are on offer anyway, so that negotiability comes off the table.


------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 12-01-2019 11:49
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

In the book by Keith Hill called "Treatise on the True Art of Making Musical Instruments, A Practical Guide to the Hidden Craft of Enhancing Sound" (Yes, That's the whole Title)
The author discusses Membrane Driving Points and offers a diagram. He explains that the driving points are in musical ratios. He later explains how past makers put the bridges on those locations. For me, the author doesn't explain how those positions are found. Can anyone figure it out?
(see pics)
Thanks

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------

Walter, what you said makes perfect sense. However, i have been unable to make it work. Unless the diagram isn't to scale, which is a possibility.

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------

Original Message:
Sent: 12-01-2019 17:31
From: Walter Bagnall
Subject: Membrane Driving Point Ratio Help

I'll take a guess.
It looks like the author is making a geometry problem out of it.
First, Find the exact center (centroid) of the soundboard.  For the triangular shape he is showing from what is probably a harpsichord, it wouldn't be difficult to find.
Second, measure out from the centroid to each of the three sides with a perpendicular line.
Third, Divide these lines into 6 segments.
The points then create the nested triangles he is showing in the diagram (except the innermost triangle which is omitted)
That's how I interpret his diagram.  Whether it produces a better sounding instrument or not I have no idea.

------------------------------
Walter Bagnall RPT
[Better Music Piano Tuning]
Chillicothe OH
[www.bettermusicpianotuning.com]

Original Message:
Sent: 12-01-2019 16:57
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

Sure, the bridge shape may not be that negotiable, but the bridge location on the piano certainly is via case shape, cut off bar, etc. I'm not sure how he is calculating the ratios.

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720

Original Message:
Sent: 12-01-2019 16:37
From: Jim Ialeggio
Subject: Membrane Driving Point Ratio Help

I don't think is has much to do with the membrane at all. The musical ratio, is defined by how long a particular frequency's speaking length has to be relative given the breaking load of the wire you are using. In the treble sections there is not much room to mess with shape much, which is why a D has pretty similar treble shape to a 5 ft piano. The treble shape of the bridge is really determined for us by the physical parameters of each note's frequency and wire being used. As the scale descends from the treble, one can mess with the lengths some, but only in a way that compromises bp% numbers, if wraps are not part of the mix. There is more messing allowed in a scale using wrapped strings,  depending on where the bass break is chosen to be, but really, in a plain wire scale, the wire you are using determines length.

I have played with the numbers, to see if I could change bridge shape. Doing this, one quickly sees, especially in the two treble sections,  that the shape of the bridge is not terribly negotiable, and is determined by the frequency and breaking point numbers. I suppose you can choose to move the front termination to effect bridge shape, but given strike point rations, that number as well, is not negotiable much either. In the treble, there is none to very little negotiability, and in the tenor some but not much.

In wrapped sections, there is more length negotiation available, but, from the look of this dude's drawings, I'm not thinking any wraps are on offer anyway, so that negotiability comes off the table.


------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 12-01-2019 11:49
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

In the book by Keith Hill called "Treatise on the True Art of Making Musical Instruments, A Practical Guide to the Hidden Craft of Enhancing Sound" (Yes, That's the whole Title)
The author discusses Membrane Driving Points and offers a diagram. He explains that the driving points are in musical ratios. He later explains how past makers put the bridges on those locations. For me, the author doesn't explain how those positions are found. Can anyone figure it out?
(see pics)
Thanks

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------

I emailed the author and this was the answer:

" Did you take a 4' x 8'x 1/8th" sheet of masonite and attempt to cut out several shapes such as I show in the text and proceed to tap on them to locate any of the 'landmarks' I show in the diagrams?"


-chris

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------

Original Message:
Sent: 12-01-2019 20:20
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

Walter, what you said makes perfect sense. However, i have been unable to make it work. Unless the diagram isn't to scale, which is a possibility.

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720

Original Message:
Sent: 12-01-2019 17:31
From: Walter Bagnall
Subject: Membrane Driving Point Ratio Help

I'll take a guess.
It looks like the author is making a geometry problem out of it.
First, Find the exact center (centroid) of the soundboard.  For the triangular shape he is showing from what is probably a harpsichord, it wouldn't be difficult to find.
Second, measure out from the centroid to each of the three sides with a perpendicular line.
Third, Divide these lines into 6 segments.
The points then create the nested triangles he is showing in the diagram (except the innermost triangle which is omitted)
That's how I interpret his diagram.  Whether it produces a better sounding instrument or not I have no idea.

------------------------------
Walter Bagnall RPT
[Better Music Piano Tuning]
Chillicothe OH
[www.bettermusicpianotuning.com]

Original Message:
Sent: 12-01-2019 16:57
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

Sure, the bridge shape may not be that negotiable, but the bridge location on the piano certainly is via case shape, cut off bar, etc. I'm not sure how he is calculating the ratios.

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720

Original Message:
Sent: 12-01-2019 16:37
From: Jim Ialeggio
Subject: Membrane Driving Point Ratio Help

I don't think is has much to do with the membrane at all. The musical ratio, is defined by how long a particular frequency's speaking length has to be relative given the breaking load of the wire you are using. In the treble sections there is not much room to mess with shape much, which is why a D has pretty similar treble shape to a 5 ft piano. The treble shape of the bridge is really determined for us by the physical parameters of each note's frequency and wire being used. As the scale descends from the treble, one can mess with the lengths some, but only in a way that compromises bp% numbers, if wraps are not part of the mix. There is more messing allowed in a scale using wrapped strings,  depending on where the bass break is chosen to be, but really, in a plain wire scale, the wire you are using determines length.

I have played with the numbers, to see if I could change bridge shape. Doing this, one quickly sees, especially in the two treble sections,  that the shape of the bridge is not terribly negotiable, and is determined by the frequency and breaking point numbers. I suppose you can choose to move the front termination to effect bridge shape, but given strike point rations, that number as well, is not negotiable much either. In the treble, there is none to very little negotiability, and in the tenor some but not much.

In wrapped sections, there is more length negotiation available, but, from the look of this dude's drawings, I'm not thinking any wraps are on offer anyway, so that negotiability comes off the table.


------------------------------
Jim Ialeggio
grandpianosolutions.com
Shirley, MA
978 425-9026

Original Message:
Sent: 12-01-2019 11:49
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

In the book by Keith Hill called "Treatise on the True Art of Making Musical Instruments, A Practical Guide to the Hidden Craft of Enhancing Sound" (Yes, That's the whole Title)
The author discusses Membrane Driving Points and offers a diagram. He explains that the driving points are in musical ratios. He later explains how past makers put the bridges on those locations. For me, the author doesn't explain how those positions are found. Can anyone figure it out?
(see pics)
Thanks

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------

While the bridge shape is somewhat non negotiable (as Jim points out), the location of the bridge on the soundboard overall certainly is, though not, perhaps, without some redesign.  How these positions are determined as optimal is a question and without reading the text I don't know what the author is getting at.  One way to think of it, however, is like a drum head.  The tone of the drum changes considerably depending on where in proximity to the center that you strike it.  What is the optimal place for transferring string vibrations to the overall diaphragm?  I don't know the answer.  But certainly different locations have different impedance characteristics.  The center offers the lowest impedance, toward the perimeter, being somewhat stiffer, higher impedance.  The natural frequency, or timbre, also changes depending on where you strike the diaphragm.  So it's an interesting question complicated by things like soundboard thinning, rib shapes and locations, and I'm sure a bunch of other things I can't think of at this early hour.

------------------------------
David Love RPT
www.davidlovepianos.com
davidlovepianos@comcast.net
415 407 8320
------------------------------

Original Message:
Sent: 12-01-2019 11:49
From: Chris Chernobieff
Subject: Membrane Driving Point Ratio Help

In the book by Keith Hill called "Treatise on the True Art of Making Musical Instruments, A Practical Guide to the Hidden Craft of Enhancing Sound" (Yes, That's the whole Title)
The author discusses Membrane Driving Points and offers a diagram. He explains that the driving points are in musical ratios. He later explains how past makers put the bridges on those locations. For me, the author doesn't explain how those positions are found. Can anyone figure it out?
(see pics)
Thanks

------------------------------
If it's pinging, it's not singing, it's just ringing,
chernobieffpiano.com
grandpianoman@protonmail.com
Knoxville, TN
865-986-7720
------------------------------