How tight should a sound post be

[Marty Kasprzyk]

5 hours ago, HoGo said:

The adjustable posts are usually much heavier than simple spruce stick due to need of movable feet and some screw mechanism so they affect sound of violin in their own ways so are hardly comparable to traditional post. They are also quite expensive and you wouldn't want to install and adjust them on your own as they could easily lead to soundpost crack or other damage to violin.

If someone invented adjustable post that would weigh same as normal post then there's a chance it would stick with violin folks.

Attached is a photo of an experimental  light weight adjustable soundpost.  It was taken from the attached dissertation "The Mechanics of the Soundpost in the Violin" by Myles Nadarajah written in 2018.  See Section 7.4 "Experiments with an adjustable soundpost" on page 165.

also see Section 3.5.1 "The effect of adding mass" (to the soundpost) 

 

MylesNadarajah_PhDThesis.pdf

[martin swan]

1 minute ago, Victor Roman said:

Am curious as to what you mean. Take the soundpost out of a violin and then use it to play the 1st in a fairly busy quartet. It won't work. That means to me, it does have at least one function. 

I'm differentiating between function (which involves design intention) and effect (which may not be part of the design intention).

[Victor Roman]

1 minute ago, martin swan said:

I'm differentiating between function (which involves design intention) and effect (which may not be part of the design intention).

Thank you, I understand. Common sense would tell me it was initially intended to strengthen things. But then, a lot of common sense doesn't work with violins.

[LCF]

10 hours ago, Gavin R said:

.... I notice that some luthiers select and tune a post so that it has the same natural frequency as the top and back. This would presumably promote resonance at that particular frequency.

One wonders which one of the hundreds of plate resonances that might be?

[LCF]

4 hours ago, martin swan said:

I mean was the soundpost invented in order to perform a function, or is it a feature which evolved/was inherited from other instruments or objects and which happens to have effects (many of which resist all attempts at systematization).

I would speculate that the soundpost was initially simply a brace ie. to prevent thinner and therefore more resonant and musically appealing plates from breaking or collapsing.

The utility of various "solutions", ie stuff you can do,  is an obvious evolutionary force. For instance you don't find posts on most plucked or strummed instruments instead there are various bracing systems. Posts or asymmetrical bridge and soundboard arrangements work on bowed instruments but not so well on non-bowed. 

A more interesting mystery is how a bridge came to be used in the first place.

[martin swan]

6 minutes ago, LCF said:

 

A more interesting mystery is how a bridge came to be used in the first place.

Bowing clearance?

[AaronS76]

Great thread. Going out of my mind trying to fit my first sound post. Too tight then too loose. Onto my fifth sound post. Hopefully I’ll get it this time with out the sound post full of holes

[LCF]

41 minutes ago, martin swan said:

Bowing clearance?

Inherited from earlier non-bowed types. It goes back a looong way. Certainly from ancient  Egypt. 

 

The correct answer is the one which would have sent a chalk duster flying across the room from the hand of my English teacher in high school;

"The reason why is because."

[LCF]

5 hours ago, Marty Kasprzyk said:

 "The Mechanics of the Soundpost in the Violin" by Myles Nadarajah written in 2018.  

.. eyes glazed over at the second double integral ...

[Blank face]

11 hours ago, Marty Kasprzyk said:

Attached is a photo of an experimental  light weight adjustable soundpost.  It was taken from the attached dissertation "The Mechanics of the Soundpost in the Violin" by Myles Nadarajah written in 2018.  See Section 7.4 "Experiments with an adjustable soundpost" on page 165.

also see Section 3.5.1 "The effect of adding mass" (to the soundpost) 

 

MylesNadarajah_PhDThesis.pdf 36.41 MB · 5 downloads

Here’s another light weight adjustable soundpost bearing a patent number. The idea might have been “Keep things simple”.

Personally I like the anecdote of the famous restorer, strumming a ruler over an edge of the bench and saying “that’s all you need to know (about soundpost adjustments).”
What was his name?

 

[martin swan]

7 hours ago, LCF said:

Inherited from earlier non-bowed types. It goes back a looong way. Certainly from ancient  Egypt. 

 

The correct answer is the one which would have sent a chalk duster flying across the room from the hand of my English teacher in high school;

"The reason why is because."

Agree - but the high bridge, resulting string tension and need for a bracing system (post) is presumably medieval ...

[David Burgess]

On 10/27/2024 at 8:00 AM, Gavin R said:

I am a physicist so my view of the mechanics would be that the tension on the strings will compress the body slightly along the length of the belly and back.

I'd suggest that you give a little more thought to what happens with the back, given that the longitudinal compression from the strings is above the surface of the top. Think in terms of levers reversing the direction of force and stuff.

[LCF]

1 hour ago, David Burgess said:

I'd suggest that you give a little more thought to what happens with the back, given that the longitudinal compression from the strings is above the surface of the top. Think in terms of levers reversing the direction of force and stuff.

Yup. That is well illustrated by a different ruler analogy to the one mentioned by BF. If you hold a ruler horizontally and bend it upwards ie concave face up, convex face downwards, the upper surface is compressed and the lower is stretched. 

 

But I didn't understand BF's analogy anyway ...

[LCF]

2 hours ago, martin swan said:

Agree - but the high bridge, resulting string tension and need for a bracing system (post) is presumably medieval ...

Pic of a Germanic lyre from Ca. 580AD ( from Trossingen),   a strummed/plucked instrument. The soundboard is tapered btw, 7mm or so thick under the bridge to much thinner at the edges. It has a nice tall bridge which looks modern not unlike some mandolin or arch top guitar bridges. They must have played these things quite hard!

https://images.app.goo.gl/oDy7mZbf9HbXf4co8

That bridge is made from willow. Some others were cast in bronze. 

 

The very simple underlying function of a bridge, or bridge plus soundpost, is as a system of mechanical advantage which turns some specific type of input force into as much output movement as possible. 

 

[Blank face]

52 minutes ago, LCF said:

But I didn't understand BF's analogy anyway ...

It wasn't mine, but sort of hearsay. BTW it was the same guy who allegedly fitted a pencil into the violin of a demanding customer..

[Christian Pedersen]

These anecdotes have been attributed to René Morel.

[martin swan]

1 hour ago, LCF said:

Pic of a Germanic lyre from Ca. 580AD ( from Trossingen),   a strummed/plucked instrument. The soundboard is tapered btw, 7mm or so thick under the bridge to much thinner at the edges. It has a nice tall bridge which looks modern not unlike some mandolin or arch top guitar bridges. They must have played these things quite hard!

https://images.app.goo.gl/oDy7mZbf9HbXf4co8

That bridge is made from willow. Some others were cast in bronze. 

 

The very simple underlying function of a bridge, or bridge plus soundpost, is as a system of mechanical advantage which turns some specific type of input force into as much output movement as possible. 

 

Of course bridges have been around since BC, but bridges on strummed or plucked instruments don't need curvature in the way that a multi-stringed bowed instrument does.

My supposition is that as bowing became more sophisticated (traditional bowed instruments from Asia only bow one or two strings) the curvature of the bridge needed to be increased resulting in greater string angle, so the string tension increased and the need for bracing of the plates arose. Hence the soundpost.

[Dr. Mark]

2 hours ago, LCF said:

Pic of a Germanic lyre from Ca. 580AD (

Maybe this: Someone may have noticed that a sound board coupled to vibrating strings is louder and resonates in a pleasant way (I think George Harrison used to hold his guitar neck against a cabinet in lieu of an amplifier).  There are a couple of effective ways to connect a sound board or drum skin to strings - vertically like a harp, and horizontally like the illustrated German instrument.  If horizontal there are two things that become immediately apparent:  first, the strings aren't directly coupled to the sound board so where's the nice resonance?  Something under the strings makes that connection.  The second is a clearance issue wrt fingering and the strings over the sound board.  Like the bridge curvature supposition above, the better makers would be trying to solve practical issues for personal satisfaction or in response to customer demand.

I also recall reading recently that up to around the time of Amati the sound post in the violin and similar instruments was centered on the instrument rather than under the bridge.  I've been looking around to locate that source.

__________

Now lost to the ocean of time.  We are stranded on the rocky coast of the present, with only scattered beams and flotsam of the past as testimony to the once vigorous lives and dreams now consigned to it's unplumbable depths.  Fugit irrevocable tempus.

[Bodacious Cowboy]

18 hours ago, martin swan said:

I mean was the soundpost invented in order to perform a function, or is it a feature which evolved/was inherited from other instruments or objects and which happens to have effects (many of which resist all attempts at systematization).

I would speculate that the soundpost was initially simply a brace ie. to prevent thinner and therefore more resonant and musically appealing plates from breaking or collapsing.

But the soundpost is so fundamental to the acoustic performance of a violin that even if the original intention were entirely structural support, wouldn't it very quickly become apparent that there was an acoustic enhancement also? Is it relevant that the latter might have originated as a serendipitous "side effect"? 

[Blank face]

There are pictorial and physical evidences that a through-the-top post (as a relief, not support for the top, and not moveable) existed in viols in the 16th century, similar to a celtic Crwth, and squarish central soundposts in front of the bridge (the unaltered Freiberg decorative instruments) in the 17th.

But which was the first, how wide spread these were used, and in which regions is left to speculation IMO, at least at the actual state of research.

https://maestronet.com/forum/index.php?/topic/338433-central-soundpost-christian-rault/

 

[martin swan]

9 minutes ago, Bodacious Cowboy said:

But the soundpost is so fundamental to the acoustic performance of a violin that even if the original intention were entirely structural support, wouldn't it very quickly become apparent that there was an acoustic enhancement also? Is it relevant that the latter might have originated as a serendipitous "side effect"? 

Of course, but that's an effect not a function.

I suppose I'm questioning the way a modern scientific mind attempts to quantify and sytematize soundpost adjustment, starting from the (false) premise that tonal balance and response are somehow a function of the post rather than a by-product.

I don't believe that changes in post position have predictable or reliably measurable or perceptible results across different instruments.

[GoPractice]

Two things leading to other thoughts, for some?

Much like players ( often younger or inexperienced ) who do not fully realize potential string complexity, string quality is difficult to judge unless fully utilized. Not about maximizing output but discovering or understanding a variety of qualities or characteristics? If that player is happy with how a string sounds, might last years, certainly I am not to fault them for that joy.

There are players who under- utilize a well set up post.

In teaching or explaining concepts or the complexity of bowing, sometimes I have to explain that there is a soundpost in an instrument. There are university level students who have no idea. That the coupling allows for what is a bowed instrument quality, that it is necessary to play through to the back of the instrument to fully ( to see what the player can do. ) That it is not entirely about the force one applies, but how one applies it.

And a soundpost post fit " properly " helps in making some players work at another level. There are grads and strings, and so many factors. But a better observer might know how a slight adjustment might make it easier or better or worse or harder for a player. Coupled mass might be less sensitive to activation, but once started would have more sustained vibration.

[uguntde]

I recently adjusted a highly arched viola because I didn't like the sound. I made a sound post for which I made sure it fits by looking through the end pin hole. As I was not happy with the sound I eventually release s.p. pressure - with a high arching this requires a very small move. I ended up with a mch more pleasing sound quality. But there is no rule, for another instrument the opposite may work - at least this is my impression.

[LCF]

7 hours ago, martin swan said:

Of course bridges have been around since BC, but bridges on strummed or plucked instruments don't need curvature in the way that a multi-stringed bowed instrument does.

My supposition is that as bowing became more sophisticated (traditional bowed instruments from Asia only bow one or two strings) the curvature of the bridge needed to be increased resulting in greater string angle, so the string tension increased and the need for bracing of the plates arose. Hence the soundpost.

Perhaps that's where we have ended up for now but i don't think there is a direct link between bridge curvature and increased string tension. The sides of a bridge can be lowered as easily as the centre is raised and that lowering leads to the other violin-like characteristic of cutaway sides. 

[David Burgess]

13 hours ago, Blank face said:

Personally I like the anecdote of the famous restorer, strumming a ruler over an edge of the bench and saying “that’s all you need to know (about soundpost adjustments).”

 

8 hours ago, Christian Pedersen said:

These anecdotes have been attributed to René Morel.

Didn't Rene steal the ruler analogy from Andrea Amati?