Downbearing Measurements

[Regi Hedahl]

Today, I measured the downbearing on a 1955 Steinway M and a 1934 Mason & Hamlin A. I used a digital inclinometer called TiltBox. Both pianos have not been rebuilt and both have no crown measured throughout various sections of the soundboard from underneath using a piece of thread. The Steinway enjoyed most of its life in the Pacific Northwest and the Mason & Hamlin spent most of it's life in an old Louisiana farm house without heating and air conditioning.  One of the reasons I took measurements was so I could get baseline values. I want to better educate some customers on the tonal deficiencies of their pianos. I tune a lot of pianos with very short tone in the treble but as we know, a good tuning does not improve this. I have a new customer who is complaining of this after tuning her crummy Kimbal baby grand. Not sure exactly what to do short term but I may end up having to slightly detune each unison to satisfy the customer.  Some people get used to shimmering unisons on their tonally dead piano.

What downbearing values are commonly measured on pianos with serious tonal deficiencies?

Downbearing values measured in degrees

Regi Hedahl

[Terry Farrell]

Are the angular values reflecting the difference between the attitude of the speaking section vs the back-scale section?

Terry Farrell

<Downbearing.jpg>

[Ron Nossaman]

On 12/1/2015 7:49 PM, Terry Farrell wrote:
> Are the angular values reflecting the difference between the attitude of
> the speaking section vs the back-scale section?

If you can come up with a verifiable correlation on that one, I'll be
vastly impressed and you'll make piano history.
Ron N

[Ron Nossaman]

> What downbearing values are commonly measured on pianos with serious
> tonal deficiencies?

It doesn't work that way. The stiffness, thus impedance of the system is
evident as a balance between crown and bearing. What load is the board
supporting at what crown.
Ron N

[Regi Hedahl]

Terry,

The values are the angular difference between the speaking length and backscale length.

Regi

[Joseph Garrett]

What are the increments? Degrees? Inches? MMs? Snowflakes?<G>
Joe


Captain of the Tool Police
Squares R I
gpianoworks.com

[Terry Farrell]

You’re so funny Joe!  As Regi labeled on the table: “Downbearing values measured in degrees”

(snicker, snicker, snicker…..)  No worry, I’ve missed the obvious too many times to count - not that that is saying much…….  ;-)

Terry Farrell

[Ron Nossaman]

> What downbearing values are commonly measured on pianos with serious
> tonal deficiencies?

Sorry. I didn't finish. The Kimball is most likely just what you said.
Noise is tone. No noise, no tone. Too many people have never heard a
piano in tune and have no idea what they're hearing. Like most things,
you aren't likely to be able to explain the difference to them. I wish I
had a better answer.

I think that's all.
Ron N

[Ron Nossaman]

On 12/1/2015 8:50 PM, Joseph Garrett wrote:
> What are the increments? Degrees? Inches? MMs? Snowflakes?<G>
> Joe

Read the bloody post, Joe. He said degrees.
Ron N

[Terry Farrell]

Is that directed my way? I really don’t understand what you are describing. Please explain. Thanks.

Terry Farrell

[Ron Nossaman]

On 12/1/2015 9:00 PM, Terry Farrell wrote:
> Is that directed my way? I really don’t understand what you are
> describing. Please explain. Thanks.

Yes it was. Explain, please, the result of an imbalance or whatever,
between front and rear bearing independent of overall bearing.
Ron N

[Joseph Garrett]

Ooopsie!<G>

Joe

-----Original Message-----
From: Terry Farrell
Sent: Dec 1, 2015 6:53 PM
To: pian...@googlegroups.com
Subject: Re: [pianotech] Downbearing Measurements

You’re so funny Joe!  As Regi labeled on the table: “Downbearing values measured in degrees”

(snicker, snicker, snicker…..)  No worry, I’ve missed the obvious too many times to count - not that that is saying much…….  ;-)

Terry Farrell

On Dec 1, 2015, at 9:50 PM, Joseph Garrett <joega...@earthlink.net> wrote:

What are the increments? Degrees? Inches? MMs? Snowflakes?<G>
Joe

Captain of the Tool Police
Squares R I
gpianoworks.com


-----Original Message-----

From: Regi Hedahl <piano...@gmail.com>
Sent: Dec 1, 2015 6:38 PM
To: pianotech <pian...@googlegroups.com>
Subject: Re: [pianotech] Downbearing Measurements

Terry,

The values are the angular difference between the speaking length and backscale length.

Regi

[Terry Farrell]

What am I missing here. The difference between the attitude of the speaking section and the back-scale section defines overall bearing. Correct? I know the bridge top attitude can come into play for sure, but the overall bearing is between the speaking and back sections. I’m missing something - what is it?

Terry Farrell

[Terry Farrell]

There ya go! Mud on your face!!!  Hey, I’ve got all sorts of cleansers for that - I have lots of experience - hey, what can I say……

Terry Farrell

[Paul Bruesch]

Digital Tourette's...

[Ron Nossaman]

On 12/1/2015 9:16 PM, Joseph Garrett wrote:
> Ooopsie!<G>

Hah!

[Ron Nossaman]

On 12/1/2015 9:19 PM, Terry Farrell wrote:
> What am I missing here. The difference between the attitude of the
> speaking section and the back-scale section defines overall bearing.
> Correct? I know the bridge top attitude can come into play for sure,
> but the overall bearing is between the speaking and back sections.
> I’m missing something - what is it?

Someone always wants to know front and back bearing. Why? How often has
that been important compared to overall?
Ron N

[Ron Nossaman]

On 12/1/2015 9:21 PM, Paul Bruesch wrote:
> Digital Tourette's...

MEEPH!
Ron N

[Terry Farrell]

But front and back bearing define overall bearing. Again, what am I missing?

I do realize that the bridge could be rolled. HA! I said that just to get your goat. But yes, the soundboard can be horribly distorted - often into an S-shaped curve - and still overall bearing looks good. Is that what you are getting at?

Sorry for my cranial cramps.

Terry Farrell

[Ron Nossaman]

On 12/1/2015 9:50 PM, Terry Farrell wrote:
> But front and back bearing define overall bearing. Again, what am I
> missing?

Why would you even ask about front and back bearing? What am I missing?

> I do realize that the bridge could be rolled. HA! I said that just to
> get your goat. But yes, the soundboard can be horribly distorted -
> often into an S-shaped curve - and still overall bearing looks good.
> Is that what you are getting at?

No, I want to know why you even asked about front and back bearing.
Ron N

[Terry Farrell]

Because knowing that, and the string tension, one can calculate downbearing pressure

Terry Farrell

[Ron Nossaman]

On 12/1/2015 10:17 PM, Terry Farrell wrote:
> Because knowing that, and the string tension, one can calculate downbearing pressure

Yes, from overall bearing. AGAIN - WHY WOULD YOU ASK ABOUT FRONT AND
BACK BEARING WHEN YOU WANT OVERALL? Sorry, I just don't know any other
words to ask the same question again.
Ron N

[David Skolnik]

Sorry. It seems Terry is taking flack for what would have been me, had I seen this thread last night.  RonN.  Why are you going bonkers about distinguishing front and rear downbearing?  Are you saying that they don't exist as distinctively discrete measurements?  That it's not possible to find various combinations of values, some negative, that would still result in a positive net?  Does a positive net bearing trump (sorry) any other bearing-configuration concerns?

The configuration of the interface device that Regi is using (between Tilt box and string) might be a limiting factor. 
If your comment was directed at Regi's initial question:

What downbearing values are commonly measured on pianos with serious tonal deficiencies?

Then it would seem to make more sense.  I don't get why you're going after Terry for simply asking about front and rear.

David Skolnik
Hastings on Hudson, NY

---

This email has been checked for viruses by Avast antivirus software. www.avast.com

[Joseph Garrett]

Would you believe because he can?

Just my take on it.

Joe

-----Original Message-----
From: David Skolnik
Sent: Dec 2, 2015 4:39 AM
To: pian...@googlegroups.com
Subject: Re: [pianotech] Downbearing Measurements

[David Skolnik]

Or cannot not?
Are we stoking the embers?  Do we actually want to 'go there'?
ds

[Ron Nossaman]

On 12/2/2015 6:39 AM, David Skolnik wrote:
>>
> I don't get why you're going
> after Terry for simply asking about front and rear.

Going after? Can't I ask what he had in mind when he asked the question,
and expect an answer without you making a big deal out of it? Apparently
no one else is interested or curious, and just assumed Terry's question
was random, arbitrary, and meaningless. I at least gave him benefit of
the doubt and asked for clarification as to why he asked about front and
back bearing. You don't seem to want to know, but you're sure quick to
rag me about asking. And I still didn't get an answer, did I, but now
I'm the bad guy for asking a simple question?

Swell.
Ron N

[David Skolnik]

Realizing that it would be a far reach for us to resolve this in a way that's reflective of our collective age(s), I'll nevertheless try.

I'm not trying to demonize you or otherwise mis-characterize your statements.  You are not the bad guy.  There just seems to be some miscommunication. When you initially said:

If you can come up with a verifiable correlation on that one, I'll be vastly impressed and you'll make piano history.
Ron N

it appeared as a response to Terry's question:

Are the angular values reflecting the difference between the attitude of the speaking section vs the back-scale section?

which didn't entirely make sense to me.  It seemed more appropriately directed at  Regi's comment:

What downbearing values are commonly measured on pianos with serious tonal deficiencies?

And yet, when Terry asked:

Is that directed my way? I really don’t understand what you are describing. Please explain. Thanks.

you indicated it was:

Yes it was. Explain, please, the result of an imbalance or whatever, between front and rear bearing independent of overall bearing.
Ron N

except, to my reading, Terry never presented the idea of 'imbalance... between front and rear bearing'.  He seemed to be asking what Regi's numbers represented.

And then it proceeded:

Someone always wants to know front and back bearing. Why? How often has that been important compared to overall?
Ron N

Why would you even ask about front and back bearing? What am I missing?

No, I want to know why you even asked about front and back bearing.
Ron N

Yes, from overall bearing. AGAIN - WHY WOULD YOU ASK ABOUT FRONT AND BACK BEARING WHEN YOU WANT OVERALL? Sorry, I just don't know any other words to ask the same question again.
Ron N

Yes, the net downbearing is the primary factor, (depending of course on how it's measured) but your responses suggest that you see the consideration of front and rear bearing, as discreet entities, as irrelevant.  If that reading is erroneous, I apologize.

David Skolnik
Hastings on Hudson, NY

[David Kroenlein]

Seems to me the back bearing angle ill always be greater, due to the shorter distance from the nack of the bridge to the hitch pin......

Sent from my iPhone

[Will Truitt]

Not always, particularly in the high treble. I have seen negative rear bearing and a ton of front bearing on many pianos. Whether or not it should be there is another story.

Will Truitt

-----Original Message-----
From: pian...@googlegroups.com [mailto:pian...@googlegroups.com] On Behalf Of David Kroenlein
Sent: Wednesday, December 02, 2015 12:46 PM
To: pian...@googlegroups.com
Subject: Re: [pianotech] Downbearing Measurements

[Ron Nossaman]

On 12/2/2015 11:46 AM, David Kroenlein wrote:
> Seems to me the back bearing angle ill always be greater, due to the
> shorter distance from the nack of the bridge to the hitch pin......

No, it could be anything.

Since Terry won't answer me, maybe someone else will tell me something
sensible and verifiable about the importance of measuring front and back
bearing in the instance that started this Keystone Kops routine.
Ron N

[Terry Farrell]

I ask about front and rear bearing angles because that is how one can determine overall down bearing. And if one wants to know the amount of down bearing pressure (which I do know IS down bearing) one would incorporate string tension into the calculation.

I know you like people to think and come up with the answer themselves if they can. And personally, I think that is a fine thing - a good exercise indeed. I’m quite apparently missing something and I just don’t know what it is, nor where to find the answer. A clue?

And FWIW, I don’t feel picked upon! :-)

Terry Farrell

[Ron Nossaman]

On 12/2/2015 12:53 PM, Terry Farrell wrote:
> I ask about front and rear bearing angles because that is how one can
> determine overall down bearing. And if one wants to know the amount
> of down bearing pressure (which I do know IS down bearing) one would
> incorporate string tension into the calculation.

Yes, of course. That's the overall bearing. Calibrate on speaking
length, check back length in comparison, and that is the overall
bearing. Front and rear bearing are taken from the bridge top, relative
to speaking length for front bearing, and relative to the back length
for rear bearing.

I guess I misunderstood what you asked. I thought you had asked for
front and rear bearing. My mistake.

Ron N

[Terry Farrell]

Many assumptions would have to be made, such as: the plane of the bridge top would have to be above the capo bar/agraffe and the back scale rear termination - that may not be true after soundboard distortion has occurred (or maybe it wasn’t that way from the factory!); the plane of the bridge top and a plane defined by the speaking length forward termination and the back scale rear termination would need to be nearly parallel.

Terry Farrell

[Terry Farrell]

I don’t do internet on the road. I know, I’m strange, but that’s just how I am.

Terry Farrell

[Terry Farrell]

Yes, of course. That's the overall bearing. Calibrate on speaking length, check back length in comparison, and that is the overall bearing. Front and rear bearing are taken from the bridge top, relative to speaking length for front bearing, and relative to the back length for rear bearing.

I guess I misunderstood what you asked. I thought you had asked for front and rear bearing. My mistake.

Ron N

You may have misunderstood what I asked. I may have misunderstood what you asked. I may have misunderstood what I asked (hugh)! Actually, I think that maybe I didn’t really even take enough time to think clearly about what you were saying. I was just thinking the difference between the attitude of the speaking length compared to the back scale. But you are correct that if one asks the question “what is the front bearing”, one would also have to measure the attitude of the bridge top. I think that is where our communication went astray. My fault.

I do value your input and know that you don’t write posts for no reason - so I’m trying to understand…….

On 12/1/2015 7:49 PM, Terry Farrell wrote:

Are the angular values reflecting the difference between the attitude of
the speaking section vs the back-scale section?

If you can come up with a verifiable correlation on that one, I'll be vastly impressed and you'll make piano history.
Ron N

Are you asking about a verifiable correlation among the values for this particular example, or are you asking about correlation between the attitude of the speaking section compared to the back scale section?

Explain, please, the result of an imbalance or whatever, between front and rear bearing independent of overall bearing.
Ron N

Again, I’m not sure exactly what you are asking, but I don’t often consider so closely/independently front and/or rear bearing independent of overall bearing. I may look at front and rear bearing to get some idea of how misshapen the board might be or how poorly the bridge was originally constructed, but they won’t tell you a whole lot about overall bearing by themselves. Perhaps that is the direction you were going with the question?

Terry Farrell

[Ron Nossaman]

On 12/2/2015 4:35 PM, Terry Farrell wrote:

> Again, I’m not sure exactly what you are asking, but I don’t often
> consider so closely/independently front and/or rear bearing independent
> of overall bearing. I may look at front and rear bearing to get some
> idea of how misshapen the board might be or how poorly the bridge was
> originally constructed, but they won’t tell you a whole lot about
> overall bearing by themselves. Perhaps that is the direction you were
> going with the question?

I thought you were asking about front and rear bearing, and given the
attention it's gotten through the years, no one has ever rationally
equated front and rear bearing to tonal problems unless front bearing
was severely negative. I wanted to hear your take.

No, I've got it now. Mistaken question, etc. Disregard.
Ron N

[David Skolnik]

Ron N said:

no one has ever rationally equated front and rear bearing to tonal problems unless front bearing was severely negative.

Can we be specific? 
In either front or rear bearing, what are the potential structural or tonal concerns that are conceivable, assuming that there does exist appropriate net downbearing?  How pronounced does the actual condition have to be to actualize those concerns? 

If there is positive front with negative rear, such that the net is still positive, how is the stress on the bridge/board different from the idealized set up of positive on both sides of bridge?  Can such a configuration, over time, distort the board?  What's the significance of the force on the rear segment of the bridge being in an upward mode rather than down?

If the negative aspect is in the front, what is the potential impact on termination activity, noise, stability?  What is the difference between slight, moderate and severe negativity in the front?

The concept of front bearing relates primarily to the bridge string segment directly behind the front bridge pin.

Asking these questions does not imply a specific causative linkage.

David Skolnik

At 07:11 PM 12/2/2015, you wrote:

On 12/2/2015 4:35 PM, Terry Farrell wrote:

Again, I’m not sure exactly what you are asking, but I don’t often

consider so closely/independently front and/or rear bearing independent
of overall bearing. I may look at front and rear bearing to get some
idea of how misshapen the board might be or how poorly the bridge was

originally constructed, but they won’t tell you a whole lot about

overall bearing by themselves. Perhaps that is the direction you were
going with the question?

I thought you were asking about front and rear bearing, and given the attention it's gotten through the years, no one has ever rationally equated front and rear bearing to tonal problems unless front bearing was severely negative. I wanted to hear your take.

No, I've got it now. Mistaken question, etc. Disregard.
Ron N

[Terry Farrell]

On Dec 2, 2015, at 7:53 PM, David Skolnik <davids...@optonline.net> wrote:

SNIP
If there is positive front with negative rear, such that the net is still positive, how is the stress on the bridge/board different from the idealized set up of positive on both sides of bridge?  Can such a configuration, over time, distort the board?SNIP

"Can such a configuration, over time, distort the board?”

Perhaps the more pertinent question is: did a distorted board cause the presumably undesirable downbearing condition.

Terry Farrell

[Joseph Garrett]

AND, let's just make it clear that it is not necessary to have down bearing in order to have "sustain". There are pianos designed with a reverse crown. I own one. Proper termination, i.e. bridge pins and solid bridges make the transfer of energy/vibrations into the sound board, not down bearing.
IMO, downbearing is simply an indication of part of the whole picture.
Best,
Joe

Captain of the Tool Police
Squares R I
gpianoworks.com

-----Original Message-----
>From: Will Truitt <sur...@metrocast.net>
>Sent: Dec 2, 2015 10:32 AM
>To: pian...@googlegroups.com
>Subject: RE: [pianotech] Downbearing Measurements
>
>Not always, particularly in the high treble. I have seen negative rear bearing and a ton of front bearing on many pianos. Whether or not it should be there is another story.
>
>Will Truitt
>
>
>
>-----Original Message-----
>From: pian...@googlegroups.com [mailto:pian...@googlegroups.com] On Behalf Of David Kroenlein
>Sent: Wednesday, December 02, 2015 12:46 PM
>To: pian...@googlegroups.com
>Subject: Re: [pianotech] Downbearing Measurements
>

>Seems to me the back bearing angle ill always be greater, due to the shorter distance from the nack of the bridge to the hitch pin......
>

>Sent from my iPhone
>
>> On Dec 1, 2015, at 21:19, Terry Farrell <farrellpi...@gmail.com> wrote:
>>
>> What am I missing here. The difference between the attitude of the speaking section and the back-scale section defines overall bearing. Correct? I know the bridge top attitude can come into play for sure, but the overall bearing is between the speaking and back sections. I’m missing something - what is it?
>>
>> Terry Farrell
>>
>>> On Dec 1, 2015, at 10:07 PM, Ron Nossaman <rnos...@cox.net> wrote:
>>>
>>> On 12/1/2015 9:00 PM, Terry Farrell wrote:
>>>> Is that directed my way? I really don’t understand what you are
>>>> describing. Please explain. Thanks.
>>>

>>> Yes it was. Explain, please, the result of an imbalance or whatever, between front and rear bearing independent of overall bearing.
>>> Ron N
>>
>
>

[David Skolnik]

Joe -
What is this piano of what you speak? What 'non-downbearing' specs?  Is this reverse crown and negative downbearing?  If so, how do strings remain in contact with bridge?  What do we actually mean by "proper termination"?
And so on.
David S

At 09:47 PM 12/2/2015, you wrote:

AND, let's just make it clear that it is not necessary to have down bearing in order to have "sustain". There are pianos designed with a reverse crown. I own one. Proper termination, i.e. bridge pins and solid bridges make the transfer of energy/vibrations into the sound board, not down bearing.
IMO, downbearing is simply an indication of part of the whole picture.
Best,
Joe


Captain of the Tool Police
Squares R I
gpianoworks.com


-----Original Message-----
>From: Will Truitt <sur...@metrocast.net>
>Sent: Dec 2, 2015 10:32 AM
>To: pian...@googlegroups.com
>Subject: RE: [pianotech] Downbearing Measurements
>
>Not always, particularly in the high treble.  I have seen negative rear bearing and a ton of front bearing on many pianos.  Whether or not it should be there is another story. 
>
>Will Truitt
>
>
>
>-----Original Message-----
>From: pian...@googlegroups.com [ mailto:pian...@googlegroups.com] On Behalf Of David Kroenlein
>Sent: Wednesday, December 02, 2015 12:46 PM
>To: pian...@googlegroups.com
>Subject: Re: [pianotech] Downbearing Measurements
>
>Seems to me the back bearing angle ill always be greater, due to the shorter distance from the nack of the bridge to the hitch pin......
>
>Sent from my iPhone
>
>> On Dec 1, 2015, at 21:19, Terry Farrell <farrellpi...@gmail.com> wrote:
>>

>> What am I missing here. The difference between the attitude of the speaking section and the back-scale section defines overall bearing. Correct? I know the bridge top attitude can come into play for sure, but the overall bearing is between the speaking and back sections. I’m missing something - what is it?

>>
>> Terry Farrell
>>
>>> On Dec 1, 2015, at 10:07 PM, Ron Nossaman <rnos...@cox.net> wrote:
>>>
>>> On 12/1/2015 9:00 PM, Terry Farrell wrote:

>>>> Is that directed my way? I really don’t understand what you are

>>>> describing. Please explain. Thanks.
>>>
>>> Yes it was. Explain, please, the result of an imbalance or whatever, between front and rear bearing independent of overall bearing.
>>> Ron N
>>
>
>

[Regi Hedahl]

I remember hearing that Rippen used a reverse crown soundboard. The soundboard was constructed flat and the string bearing forced it into a reverse crown.

Is there a timbral advantage by designing soundboards with positive crown along with the requisite string bearing pressing against this crown?

Regi Hedahl

[Joseph Garrett]

Rippen. The rest? Figure it out.<G>

Joe

-----Original Message-----
From: David Skolnik

[Ron Nossaman]

On 12/3/2015 8:58 AM, Regi Hedahl wrote:
> I remember hearing that Rippen used a reverse crown soundboard. The
> soundboard was constructed flat and the string bearing forced it into
> a reverse crown.

Perzina, right now this very day, uses concave crown.

> Is there a timbral advantage by designing soundboards with positive
> crown along with the requisite string bearing pressing against this
> crown?

Neither crown, nor bearing is necessary to build a piano. Crown and
bearing themselves are not important. Their importance is in what they
do. Crown in most existing pianos is martially or entirely the result of
panel compression. Some pianos have crowned ribs, but even most of them
have crown supported to a large part by panel compression. The crown
adds stiffness without additional mass as the crown is deflected by
bearing. This, then, is the function of bearing. Build a light and stiff
enough soundboard assembly, and you need neither crown, nor bearing. In
the vast majority of the pianos we see, bearing is necessary to deflect
crown, to provide the stiffness necessary to avoid the entire piano
sounding like the killer octave in a compression crowned board. Pianos
like Steinway and Baldwin are the worst. Steinway US has an entirely
compression crowned board, and Baldwin uses a 72' radius, which is close
enough to flat to be considered compression crowned in practice and
field diagnostics.

I can bury you in a thoroughly dense and impenetrable treatise on
mechanical impedance and impedance balance between board and string
scale, and the resonant frequency requirements of the board in the
different sections, which will be real and essentially correct, but no
one needs that sort of important sounding detail to understand the roll
and criticality of crown and bearing when they are chasing down tonal
problems. No charge for the enormous sentence. And no, that's not bridge
roll I mentioned.

So when we get the daily tonal problem post, we ask about the crown and
bearing throughout the piano. It's an excellent Triage step to indicate
where to look next providing we can get useful information from the
poster. That's a lot harder than it seems it ought to be because of what
they have been taught. There isn't a laminated wallet card with crown
and bearing columns, and a fix on the back under G-2, or B-4 gotten from
one measurement in thousandths, degrees, rocker guesses, and crown under
the longest rib. These are the things that waste the most time trying to
define the actual problem, and are rarely cleared up enough to
accurately do so.

Then there's the guy who posted a photo of about a 4" length of three
strings in space, against a blank background with no visible termination
and no other information and wanted to know why it sounded bad.

It's not you, honest, it's universal. Techs get a call back on a tuning
problem, and the tech can do an hour of standup on the details involved
in diagnosing and fixing the customer's perceived tuning complaint
(voicing, front duplex, false beating, scaling, etc) but they all want a
simple definitive one minute or less measurement to diagnose
soundboards. In essence, soundboards aren't that overwhelmingly
complicated. The rules are simple and have been gone over many times.
Like tuning, it requires putting interactions together instead of having
a simple rule of thumb or two that answers all the myriad interactions
in one rubber stamp.
Ron N

[Ron Nossaman]

On 12/3/2015 12:55 PM, Ron Nossaman wrote:


Sorry about all the typos. I should know better than to post with a
fever. In spite of my ineptitude, That's still basically how crown and
downbearing works.

Maybe this will post before next week. Cox is on a service upgrade
crusade. This means that to illustrate why we need to buy more service,
they hold emails back three or four hours before sending them on.
Ron N

[David Kroenlein]

Ahh! That explains a lot about the sound of perzina pianos!

Sent from my iPhone

[Terry Farrell]

Steinway has done the reverse crown thing as well on new pianos (well, at least on one). I don’t know if it was intentional or not.

Terry Farrell

[Joseph Garrett]

Terry,

I suspect "not". There have been many who have tried to get them to make decent soundboards the right way....to no avail. They're so stuck in the past it's pitiful. Sigh!

Best,

joe

-----Original Message-----
From: Terry Farrell
Sent: Dec 3, 2015 6:02 PM
To: pian...@googlegroups.com
Subject: Re: [pianotech] Downbearing Measurements

[David Skolnik]

Did it have positive (or negative) front and rear downbearing?  Sustain?  Was it considered a feature or a warrantee issue?   How did you actually measure reverse-ness?
David Skolnik


At 09:02 PM 12/3/2015, you wrote:

Steinway has done the reverse crown thing as well on new pianos (well, at least on one). I don’t know if it was intentional or not.

Terry Farrell

On Dec 3, 2015, at 9:58 AM, Regi Hedahl <piano...@gmail.com> wrote:

I remember hearing that Rippen used a reverse crown soundboard.  The soundboard was constructed flat and the string bearing forced it into a reverse crown.

Is there a timbral advantage by designing soundboards with positive crown along with the requisite string bearing pressing against this crown?

Regi Hedahl

[Terry Farrell]

Oh, I don’t really have any questions about intentionality, just thought it would be both polite and fun to post it that way!

Terry Farrell

[Terry Farrell]

On Dec 3, 2015, at 10:15 PM, David Skolnik <davids...@optonline.net> wrote:

Did it have positive (or negative) front and rear down bearing? 

Positive front and rear bearing.

Sustain? 

Decent.

Was it considered a feature or a warrantee issue?  

I guess that would depend on your point of view. This was indeed a new piano. From my perspective as the owner, it sure was a warrantee issue. From the manufacturers point of view it was not an issue.

How did you actually measure reverse-ness?

Usual way. String pulled tight across soundboard between each rib. Up to a full quarter-inch in the middle of the board - i.e. string touched board in middle and was one-quarter inch off board at both ends. Got several 8”x10” color glossy photos with circles and arrows and a paragraph on the back of each one showing this unique (or is it?) feature.

Terry Farrell

[David Skolnik]

T -
You must have done somethin to off end the manufaturer, else they would have given you anythin you want, ted.

And, pardon me, but it sounds like there's enough going on here to eve entually write your own song.   I would want to ask more (and hear more about this), but a) it deserves its own thread, to leave room for RonN's treatise on Impedance, as soon as he's feeling better (I really want to read it), and b) if you're not just spinning tales, you might be wanting to seriously pursue this issue with manufacturer, and talking too much in public, at this time, might become a liability. 

Just as long as you know that, right behind the recent work in Genetic Engineering http://www.the-scientist.com/?articles.view/articleNo/44686/title/Let-s-Talk-Human-Engineering/
and continued skepticism about global warming, this assertion of acceptable soundboard construction seems poised to be radically transformative in the way we assess, or construct pianos.  Of course, I'm temporarily overlooking this:

Neither crown, nor bearing is necessary to build a piano. Crown and bearing themselves are not important.

Get well soon, Ron.  Get a lawyer, Terry.

David Skolnik
Hastings on Hudson, NY

At 07:32 AM 12/4/2015, you wrote:

On Dec 3, 2015, at 10:15 PM, David Skolnik < davids...@optonline.net> wrote:

Did it have positive (or negative) front and rear down bearing? 

Positive front and rear bearing.

Sustain? 

Decent.

Was it considered a feature or a warrantee issue?  

I guess that would depend on your point of view. This was indeed a new piano. From my perspective as the owner, it sure was a warrantee issue. From the manufacturers point of view it was not an issue.

How did you actually measure reverse-ness?

Usual way. String pulled tight across soundboard between each rib. Up to a full quarter-inch in the middle of the board - i.e. string touched board in middle and was one-quarter inch off board at both ends. Got several 8†x10†color glossy photos with circles and arrows and a paragraph on the back of each one showing this unique (or is it?) feature.

Terry Farrell

At 09:02 PM 12/3/2015, you wrote:

Steinway has done the reverse crown thing as well on new pianos (well, at least on one). I don’t know if it was intentional or not.

Terry Farrell

[Regi Hedahl]

Terry,

What prompted you to take measurements on this piano? You mentioned sustain was decent so was there some other tonality issue?

I once had a customer who got Baldwin to replace the soundboard on their model M due to the soundboard developing a crack after purchase.

Regi Hedahl

[Terry Farrell]

Lawyer schmoyer - I don’t need no darn tooting’ lawyer. Piano story is not just a story. It was purchased by me before I go into piano technology - in fact, figuring out what was wrong with it was my introduction to piano technology. And FWIW, as a consumer, I will talk about it in public to my heart’s content - thank you very much! Piano is long since gone. Manufacturer was not willing to repair it correctly - it also had a pin block separating from the frame (you could drop a business card down into the crack) - their proposed solution was to route out a small channel over the crack and glue in a piece of spruce - so I traded it in on a slightly used Boston grand (very nice piano).

And I’m really not kidding - somewhere in my files I have a dozen or two color glossy photos with many circles and arrows and a paragraph (maybe two or three!) on the back of each one! Never got to share them with the manufacturer as I traded the sad little excuse of a piano away for a functional piano before things progressed to that point.

Terry Farrell

[David Kroenlein]

Fascinating read Dave S

Sent from my iPhone

[Terry Farrell]

On Dec 4, 2015, at 10:30 AM, Regi Hedahl <piano...@gmail.com> wrote:

What prompted you to take measurements on this piano?  You mentioned sustain was decent so was there some other tonality issue?

It has been many years and my memory is a bit fuzzy now, but it may have been my search for the little green man who lived inside the piano. Every time you’d hit G4 (or there abouts) he would come out and hit something (plate? back scale? who knows what) and make a bell-like ringing sound. That really drove my wife crazy when she would play. ‘Course, the dealer tech who first came out to investigate the little green man rumor suggested to her that “you’ll get used to it.” THAT REALLY pushed her over the edge!

I think the real reason I checked crown was that I did a bunch of research on piano design, found info on this concept of soundboard crown, and just wanted to see if there was any there - keep in mind, this was before I had ever even seen the inside of a piano.

I once had a customer who got Baldwin to replace the soundboard on their model M due to the soundboard developing a crack after purchase.

Heck, I would’ve traded her!

Terry Farrell

[Horace Greeley]

Hi, Terry,

Do you happen to remember the model and (at least approximate) serial
number?

Thanks very much.

Kind regards.

Horace

On 12/4/2015 10:31 AM, Terry Farrell wrote:
>
>> On Dec 4, 2015, at 10:30 AM, Regi Hedahl <piano...@gmail.com

[Ron Nossaman]

On 12/4/2015 9:30 AM, Regi Hedahl wrote:
> Terry,

>
> What prompted you to take measurements on this piano? You mentioned
> sustain was decent so was there some other tonality issue?

And you didn't ask, but I started taking crown measurements about the
second year I was in business when my customers occasionally noticed and
complained about the octave 5-6 tonal problems I heard in nearly every
piano I tuned and wondered why.

> I once had a customer who got Baldwin to replace the soundboard on
> their model M due to the soundboard developing a crack after
> purchase.

Me too, only it wasn't a crack. It was a killer octave in an L. They
replaced the board, beat up the case, and it sounded worse than before
they fixed it. So they sent a real tech in at great expense to voice it
away. He spent two full days, never bothered looking at the crown and
bearing, and actually did make it sound better in a lot of ways except
the original distortion and sustain problem in the killer octave which
started the whole thing. I was then instructed to stay on top of the
voicing and keep reinforcing the lie by reassuring her that the
soundboard was fine and it was just the voicing. Sorry, no. I was out a
lot of time that I never was compensated for, and nothing was gained
except for what the real imported tech soaked Baldwin for.

I don't know how many techs are aware that Baldwin had, in their
replacement parts list, replacement soundboards, ribbed and complete
with pinned bridges, that we could order. With the plate mount system
they used, you could lower the string tension, pull the plate, kick out
the soundboard, install a new one, and have the piano back up to pitch
in a day. I never cared to try it for the reason illustrated in the
story of the Baldwin replaced board. The replacement board would be like
the one taken out, or worse, which sort of defeats the purpose.

Ron N

[Will Truitt]

GASP!! The original board in a box.

I don't know, Terry. I think my customer would get upset if I kicked out the old soundboard onto her living room floor.

If thine killer octave offends thee, pluck it out.

Will

-----Original Message-----
From: pian...@googlegroups.com [mailto:pian...@googlegroups.com] On Behalf Of Ron Nossaman
Sent: Friday, December 04, 2015 2:19 PM
To: pian...@googlegroups.com
Subject: Re: [pianotech] Downbearing Measurements

[Terry Farrell]

1098. Picture below is her in all her glory. It’s the piano I learned to tune on. I’d have to do some serious digging for the serial number. Why?

I’d have to do some serious digging for the serial number, but as you can see it began with “53” and as we bought it in 1999, it was made sometime between 1994 and 1997. Probably closer to 1994, because I remember that it was five years old when we bought it as a “new” piano. Why are you interested in the serial number?

Funny thing a piano bouncing around the country for five years before finding a home (at least for a while)…….

Note the handy business card holder. And yes, that is the business card of John Patton from Steinway who came out to look for the little green man also. The little green man eluded him, and he decided the bell-like sound was likely caused by an imperfection in the plate casting at the upper speaking length termination. FWIW, most any 1098 from that era and Boston studio uprights as well (although to a lesser extent) tend to have a small colony of little green men in them. Go ahead and try it - hit G4 and a few notes around it - you’ll likely hear it: “ding!”

Terry Farrell

[David Skolnik]

I was hoping that there would be some genuine follow-up (by Ron and/or others) with regard to Ron's comments, in response to Regi Hedahl, (bolded below).  There is much there that warrants further explanation.  I'm not trying to be argumentative, nor challenge the validity of the concepts, but they deserve much more expansion than they have received, thus far.

David Skolnik
Hastings on Hudson, NY

Is there a timbral advantage by designing soundboards with positive
crown along with the requisite string bearing pressing against this
crown?

Neither crown, nor bearing is necessary to build a piano. Crown and bearing themselves are not important. Their importance is in what they do. Crown in most existing pianos is martially or entirely the result of panel compression. Some pianos have crowned ribs, but even most of them have crown supported to a large part by panel compression. The crown adds stiffness without additional mass as the crown is deflected by bearing. This, then, is the function of bearing. Build a light and stiff enough soundboard assembly, and you need neither crown, nor bearing. In the vast majority of the pianos we see, bearing is necessary to deflect crown, to provide the stiffness necessary to avoid the entire piano sounding like the killer octave in a compression crowned board. Pianos like Steinway and Baldwin are the worst. Steinway US has an entirely compression crowned board, and Baldwin uses a 72' radius, which is close enough to flat to be considered compression crowned in practice and field diagnostics.

I can bury you in a thoroughly dense and impenetrable treatise on mechanical impedance and impedance balance between board and string scale, and the resonant frequency requirements of the board in the different sections, which will be real and essentially correct, but no one needs that sort of important sounding detail to understand the roll and criticality of crown and bearing when they are chasing down tonal problems. No charge for the enormous sentence. And no, that's not bridge roll I mentioned.

[Joseph Garrett]

David,

Now you went and done it! Hopefully, Ron will "...I can bury you in a thoroughly dense and impenetrable treatise on mechanical impedance and impedance balance between board and string scale,.."  in private, so that the rest of us won't have to endure it.<G>

Imo, he answered the basic question, as I also attempted to do. Leave it alone dude.<G>

Joe

-----Original Message-----
From: David Skolnik

Sent: Dec 6, 2015 5:58 AM
To: pian...@googlegroups.com
Subject: Re: [pianotech] Downbearing Measurements

[davidskolnik]

I wouldn't expect that the effort would be worth a private posting unless adequately compensated, unless, perhaps, it entailed mainly links to previously posted or referenced materials. Besides, I could think of lots worse things to be buried in.

David Skolnik

Hastings on Hudson, NY

Sent from my Verizon Wireless 4G LTE smartphone