Pianotech

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

Petrus

Unisons should always be tuned aurally.  Tune one string to be correct in the temperament, or whatever interval you want, but then tune the other two strings to the "sample".  It not only produces a better overall unison, it also saves a lot of time.

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789
------------------------------

Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

hi Wim,
i do that: tune one string of a unison to the etd  (usually the left string with the others muted, then middle to left aurally and then the right string aurally to the others.  Just because sometimes the unisons will sound a little uneven/restless, i took a little more time today to first do it as usual and the few keys that were not sounding solid, i checked and tuned each string to the very same pitch as per etd and that simply didn't sound right. Then, after detuning one of the strings a little, sometimes sharp and sometimes flat, it would produce a "calmer" unison but in some cases i had to lower or up the pitch by a few cents to get the unison to be calmer.
Peter


------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

Original Message:
Sent: 07-28-2020 18:13
From: Willem Blees
Subject: unison tuning

Petrus

Unisons should always be tuned aurally.  Tune one string to be correct in the temperament, or whatever interval you want, but then tune the other two strings to the "sample".  It not only produces a better overall unison, it also saves a lot of time.

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789

Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

"It's complicated." Aural-only unisons is generally considered "the final word" but some ETDs have sufficiently high resolution to achieve very very clean unisons in most situations. For example, iRCT in concert mode, with resolution "cranked up" to 0.8¢, on a very high quality instrument. On the other hand, poorly matched bass strings, or lower quality wire, poor terminations, etc. will throw irregularities into the situation such that some ETD unisons will have noticeable beats.The GM-1 is an inexpensive model, with wire of lesser quality than an RX-1, or (certainly) a Shigeru.
What you hear is, of course, the final arbiter. And the customer may not want a "super super clean" unison, nor to pay for your time to get all ETD unisons 100% "digitally pure."

------------------------------
Patrick Draine
Billerica MA
978-663-9690
------------------------------

Original Message:
Sent: 07-28-2020 18:43
From: Petrus Janssen
Subject: unison tuning

hi Wim,
i do that: tune one string of a unison to the etd  (usually the left string with the others muted, then middle to left aurally and then the right string aurally to the others.  Just because sometimes the unisons will sound a little uneven/restless, i took a little more time today to first do it as usual and the few keys that were not sounding solid, i checked and tuned each string to the very same pitch as per etd and that simply didn't sound right. Then, after detuning one of the strings a little, sometimes sharp and sometimes flat, it would produce a "calmer" unison but in some cases i had to lower or up the pitch by a few cents to get the unison to be calmer.
Peter


------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055

Original Message:
Sent: 07-28-2020 18:13
From: Willem Blees
Subject: unison tuning

Petrus

Unisons should always be tuned aurally.  Tune one string to be correct in the temperament, or whatever interval you want, but then tune the other two strings to the "sample".  It not only produces a better overall unison, it also saves a lot of time.

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789

Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

hi Patrick,
you are right in that it tends to happen more frequently with older, smaller and not so high end pianos.  My ear always is the final judge.  I recently rebuilt/restrung a chickering grand and after all the work done, there was not a single false beat present:  very pleasing to the ear.  I used Paulello and Roslau wires.
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

Original Message:
Sent: 07-28-2020 19:27
From: Patrick Draine
Subject: unison tuning

"It's complicated." Aural-only unisons is generally considered "the final word" but some ETDs have sufficiently high resolution to achieve very very clean unisons in most situations. For example, iRCT in concert mode, with resolution "cranked up" to 0.8¢, on a very high quality instrument. On the other hand, poorly matched bass strings, or lower quality wire, poor terminations, etc. will throw irregularities into the situation such that some ETD unisons will have noticeable beats.The GM-1 is an inexpensive model, with wire of lesser quality than an RX-1, or (certainly) a Shigeru.
What you hear is, of course, the final arbiter. And the customer may not want a "super super clean" unison, nor to pay for your time to get all ETD unisons 100% "digitally pure."

------------------------------
Patrick Draine
Billerica MA
978-663-9690

Original Message:
Sent: 07-28-2020 18:43
From: Petrus Janssen
Subject: unison tuning

hi Wim,
i do that: tune one string of a unison to the etd  (usually the left string with the others muted, then middle to left aurally and then the right string aurally to the others.  Just because sometimes the unisons will sound a little uneven/restless, i took a little more time today to first do it as usual and the few keys that were not sounding solid, i checked and tuned each string to the very same pitch as per etd and that simply didn't sound right. Then, after detuning one of the strings a little, sometimes sharp and sometimes flat, it would produce a "calmer" unison but in some cases i had to lower or up the pitch by a few cents to get the unison to be calmer.
Peter


------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055

Original Message:
Sent: 07-28-2020 18:13
From: Willem Blees
Subject: unison tuning

Petrus

Unisons should always be tuned aurally.  Tune one string to be correct in the temperament, or whatever interval you want, but then tune the other two strings to the "sample".  It not only produces a better overall unison, it also saves a lot of time.

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789

Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

I've been thinking about unison's, in a very broad sense, for a long time now. My take on this is that it can be blamed on inharmonicity. Since inharmonicity prevents all the partials from lining up exactly, even in the best piano, I believe that that weird beat that you can make go away by slightly detuning the offending string is the result of one of the louder partials not lining up correctly and making itself painfully obvious. Detuning to make that loud errant partial quiet will make the rest of that unisons partial's a bit further out than desired but as a whole the note will be quieter/cleaner. 

Depending on where you are in the piano, the ETD is listening to a partial way above the fundamental, or 1st partial. Well, at least until the top octave. The offending partial that is causing that beat is likely not the same partial that the EDT is listening to. Therefore, you're pretty much stuck with ignoring the EDT and just detuning enough to quiet everything down, whether it's EDT correct or not.

------------------------------
Geoff Sykes, RPT
Los Angeles CA
------------------------------

Original Message:
Sent: 07-28-2020 18:43
From: Petrus Janssen
Subject: unison tuning

hi Wim,
i do that: tune one string of a unison to the etd  (usually the left string with the others muted, then middle to left aurally and then the right string aurally to the others.  Just because sometimes the unisons will sound a little uneven/restless, i took a little more time today to first do it as usual and the few keys that were not sounding solid, i checked and tuned each string to the very same pitch as per etd and that simply didn't sound right. Then, after detuning one of the strings a little, sometimes sharp and sometimes flat, it would produce a "calmer" unison but in some cases i had to lower or up the pitch by a few cents to get the unison to be calmer.
Peter


------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055

Original Message:
Sent: 07-28-2020 18:13
From: Willem Blees
Subject: unison tuning

Petrus

Unisons should always be tuned aurally.  Tune one string to be correct in the temperament, or whatever interval you want, but then tune the other two strings to the "sample".  It not only produces a better overall unison, it also saves a lot of time.

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789

Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

Original Message:
Sent: 7/28/2020 6:13:00 PM
From: Willem Blees
Subject: RE: unison tuning

Petrus

Unisons should always be tuned aurally.  Tune one string to be correct in the temperament, or whatever interval you want, but then tune the other two strings to the "sample".  It not only produces a better overall unison, it also saves a lot of time.

------------------------------
Willem "Wim" Blees, RPT
Mililani, HI 96789
------------------------------

Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

Original Message:
Sent: 7/28/2020 6:05:00 PM
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

"Falseness" in piano strings is a complicated subject. Tuning unisons of false sounding strings is complicated. I will cover one the things I know about it.

COUPLING: Strings connected by a moveable end, (bridge) allow the periods of each string to be altered by it's neighbors periods. Thus when you measure each string of a "beatless" sounding unison, you often uncover the fact that each string is at a slightly differing pitch. What is happening is the pitch of each string is slightly altered by its unison neighbors. If unison coupling is strong enough it can smooth out slow roller beats. That is what we are listening for when we really try to nail the unisons by ear. Coupling is strongest at the fundamental, except in the low strings where there often is no fundamental. The onset of unison coupling is quickest when the strings are all in the same phase with the hammer strike. That is why unphased unisons, even when well tuned, still sound slightly out of tune.




------------------------------
Edward McMorrow
Edmonds WA
425-299-3431
------------------------------

Original Message:
Sent: 07-28-2020 19:27
From: Roger Gable
Subject: unison tuning

Peter,

This came up in the recent past. I suspect you have slow rolling false beats. Tap down the string(s) at the bridge an observe if it solves the problem.

Original Message:
Sent: 7/28/2020 6:05:00 PM
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

False beats, longitudinal waves, phasing issues, etc., in addition to tuning the musical tone we have to account for the attendant distortions - tuning the noise as it were. The best results involve compromise.

------------------------------
Steven Rosenthal
Honolulu HI
808-521-7129
------------------------------

Original Message:
Sent: 07-28-2020 22:16
From: Edward McMorrow
Subject: unison tuning

"Falseness" in piano strings is a complicated subject. Tuning unisons of false sounding strings is complicated. I will cover one the things I know about it.

COUPLING: Strings connected by a moveable end, (bridge) allow the periods of each string to be altered by it's neighbors periods. Thus when you measure each string of a "beatless" sounding unison, you often uncover the fact that each string is at a slightly differing pitch. What is happening is the pitch of each string is slightly altered by its unison neighbors. If unison coupling is strong enough it can smooth out slow roller beats. That is what we are listening for when we really try to nail the unisons by ear. Coupling is strongest at the fundamental, except in the low strings where there often is no fundamental. The onset of unison coupling is quickest when the strings are all in the same phase with the hammer strike. That is why unphased unisons, even when well tuned, still sound slightly out of tune.




------------------------------
Edward McMorrow
Edmonds WA
425-299-3431

Original Message:
Sent: 07-28-2020 19:27
From: Roger Gable
Subject: unison tuning

Peter,

This came up in the recent past. I suspect you have slow rolling false beats. Tap down the string(s) at the bridge an observe if it solves the problem.

Original Message:
Sent: 7/28/2020 6:05:00 PM
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

David Klavins, builds uno corda pianos. A chance to hear pianos unencumbered by unisons and everything that comes with them.
https://www.youtube.com/watch?v=9gs7m0sGvUE

more:
https://www.youtube.com/results?search_query=klavins+una+corda+piano

------------------------------
Steven Rosenthal
Honolulu HI
808-521-7129
------------------------------

Original Message:
Sent: 07-29-2020 00:34
From: Steven Rosenthal
Subject: unison tuning

False beats, longitudinal waves, phasing issues, etc., in addition to tuning the musical tone we have to account for the attendant distortions - tuning the noise as it were. The best results involve compromise.

------------------------------
Steven Rosenthal
Honolulu HI
808-521-7129

Original Message:
Sent: 07-28-2020 22:16
From: Edward McMorrow
Subject: unison tuning

"Falseness" in piano strings is a complicated subject. Tuning unisons of false sounding strings is complicated. I will cover one the things I know about it.

COUPLING: Strings connected by a moveable end, (bridge) allow the periods of each string to be altered by it's neighbors periods. Thus when you measure each string of a "beatless" sounding unison, you often uncover the fact that each string is at a slightly differing pitch. What is happening is the pitch of each string is slightly altered by its unison neighbors. If unison coupling is strong enough it can smooth out slow roller beats. That is what we are listening for when we really try to nail the unisons by ear. Coupling is strongest at the fundamental, except in the low strings where there often is no fundamental. The onset of unison coupling is quickest when the strings are all in the same phase with the hammer strike. That is why unphased unisons, even when well tuned, still sound slightly out of tune.




------------------------------
Edward McMorrow
Edmonds WA
425-299-3431

Original Message:
Sent: 07-28-2020 19:27
From: Roger Gable
Subject: unison tuning

Peter,

This came up in the recent past. I suspect you have slow rolling false beats. Tap down the string(s) at the bridge an observe if it solves the problem.

Original Message:
Sent: 7/28/2020 6:05:00 PM
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

Ah yes,

Each string affects those nearby. Ever hear of Weinreich effect? Muting 2 strings and playing the 3rd has a different force of energy on the bridge than having all 3 strings of a unison singing. All 3 strings in a unison will really tug at the bridge...remember the bridge is not a fixed point. It can move and when it moves it changes the length and tension of the strings.

So, the more notes you play (i.e. play a big, loud chord) you will greatly affect the bridges as it wobbles all over the place from the strings vibrating and thus changing the lengths and tensions of said strings therefore changing their frequencies until dampened at which the original lengths and tensions from the state of rest will reappear.

------------------------------
Cobrun Sells
cobrun94@yahoo.com
------------------------------

Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

Weinrich did not discover unison coupling. I think is wrong to credit him with that. Weinrich actually didn't know that unison strings could be fit into phase with the hammer strike.

The strength of unison coupling is least in the high strings and strongest in the lower ones. That is why some quite "fuzzy" sounding bichord wounds can be made to sound fairly smooth when phased and tuned well.

Also the impedance is altered when unison coupling occurs.

Another source of falseness is when longitudinal modes impart angular momentum into the transverse waves. I think this happens with some regularity in the treble of pianos.

------------------------------
Edward McMorrow
Edmonds WA
425-299-3431
------------------------------

Original Message:
Sent: 07-29-2020 02:49
From: Cobrun Sells
Subject: unison tuning

Ah yes,

Each string affects those nearby. Ever hear of Weinreich effect? Muting 2 strings and playing the 3rd has a different force of energy on the bridge than having all 3 strings of a unison singing. All 3 strings in a unison will really tug at the bridge...remember the bridge is not a fixed point. It can move and when it moves it changes the length and tension of the strings.

So, the more notes you play (i.e. play a big, loud chord) you will greatly affect the bridges as it wobbles all over the place from the strings vibrating and thus changing the lengths and tensions of said strings therefore changing their frequencies until dampened at which the original lengths and tensions from the state of rest will reappear.

------------------------------
Cobrun Sells
cobrun94@yahoo.com

Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------

I have also found that when I have a "difficult" unison particularly in the tenor section, when I check the hammer/string mating, invariably there is a discrepancy (for some reason very often the right string is not being struck well). A quick work with a needle and the problem is often solved (or improved). Try this next time. 

Pwg

------------------------------
Peter Grey
Stratham NH
603-686-2395
pianodoctor57@gmail.com
------------------------------

Original Message:
Sent: 07-29-2020 10:30
From: Edward McMorrow
Subject: unison tuning

Weinrich did not discover unison coupling. I think is wrong to credit him with that. Weinrich actually didn't know that unison strings could be fit into phase with the hammer strike.

The strength of unison coupling is least in the high strings and strongest in the lower ones. That is why some quite "fuzzy" sounding bichord wounds can be made to sound fairly smooth when phased and tuned well.

Also the impedance is altered when unison coupling occurs.

Another source of falseness is when longitudinal modes impart angular momentum into the transverse waves. I think this happens with some regularity in the treble of pianos.

------------------------------
Edward McMorrow
Edmonds WA
425-299-3431

Original Message:
Sent: 07-29-2020 02:49
From: Cobrun Sells
Subject: unison tuning

Ah yes,

Each string affects those nearby. Ever hear of Weinreich effect? Muting 2 strings and playing the 3rd has a different force of energy on the bridge than having all 3 strings of a unison singing. All 3 strings in a unison will really tug at the bridge...remember the bridge is not a fixed point. It can move and when it moves it changes the length and tension of the strings.

So, the more notes you play (i.e. play a big, loud chord) you will greatly affect the bridges as it wobbles all over the place from the strings vibrating and thus changing the lengths and tensions of said strings therefore changing their frequencies until dampened at which the original lengths and tensions from the state of rest will reappear.

------------------------------
Cobrun Sells
cobrun94@yahoo.com

Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

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Petrus Janssen
Peachtree City GA
678-416-8055
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Petrus - What software are you using?

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"That Tuning Guy"
Scott Kerns
www.thattuningguy.com
Tunic OnlyPure, TuneLab & PianoMeter user
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Original Message:
Sent: 07-28-2020 18:05
From: Petrus Janssen
Subject: unison tuning

i have encountered this issue many times before and just dealt with it but since i have a little more time on my hands nowadays, i would like to know this:
Today i was tuning a Kawai GM-1 and several unisons, when tuning each string separately to the very same pitch, produced a lot of uneveness.
This piano i tune once every 12 to 18 months and its pitch was less than 1 cent off throughout.
I encounter this on pianos of all ages, brands, sizes (maybe once a week). Usually i manipulate one string to make the unison as beatless as possible but then when measuring the strings' individual pitches, they differ quite much.

So, what is causing this and are there other ways to get rid of the uneveness other than detuning one string ever so slightly until the most even sound is produced?

thank you,
Peter

------------------------------
Petrus Janssen
Peachtree City GA
678-416-8055
------------------------------