Hi everyone.

I know damping isn't the issue you like talking about, but still.
I'm trying to stop the overtones that comes out of playing B27, C28 and C#29, which are all bichords in my Kawai piano.

The C28, for example, leaves a metalic overtone at Bb62, which is of course the "sept"...

First of all, i would like to understand, why this differs from the B27 that leaves an overtone of its fifth (F#), instead.
why is the difference?!


And... of course... what is the best way to clean that sound?
I understand that there are several reasons to noises, but maybe there is a specific reason in these cases?

I have all tools to regulate, just bought them.
(As you allready guess, I'm dreaming to be a technician. Regulating my own piano i a good start for me)

THANKS A LOT FOR ANY COMMENT.

@piannoying: does the strings sound ok with the dampers liftened, or is it just when the dampers rest on the strings that you get these overtones (partials)?

Good question.

There is a difference in how I play the note.
If I use my finger or a pick (I mean like a guitar), while removing the damp completely, I don't hear any overtone.

But, if I play the note, which means striking the hammer to the string, also without the damper at all, I really can hear that partial!!!

But I doubt if the problem is caused by the shape of the hammer.
Two reasons for that:

1) The problem began after I removed the action and seated it back in place (several times), so what it has got to do with the hammer?!

2) Also, I had that problem with the B27, and somehow I suppressed the "ringing after damping". Unfortunately I didn't succeed with the C28 to the same. Any regulating doesn't work.

What do you think?
Thank you.

I've experienced three similar problems during my 20 years as a professional piano player, they all resemble what you are describing.

Although I've tuned pianos for just a couple of years and thus consider myself an intermediate tuner, I have that other "piano player" experience that might, or might not, come in handy for you here. Maybe the experienced techs can jump in and take a look at my suggestions.

1. the first, and obvious spot to check is the hammer itself. Sometimes, although they are lined up to strike the strings at a spot where you get the string moving as balanced and naturally as possible, there could be a problem there. ESPECIALLY if the shank or hammer head has been tilted the slightest bit to either sides, and you have pronounced grooves in the hammer felt! Then you might get funny ringing tones out of the hammer strike alone. This would be my bet if you removed/inserted the action several times - it doesnt take much un-alignment to get "false" notes.
   
   Somebody might tell you that it's not possible to get the very pronounced partials sounding by a badly aligned hammer, but believe me - it is. It throws of the balance in the string in some way, and all sorts of sound effects you never thought possible starts to happen
   
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2. The damper should rise in beautiful harmony with the motion that the action gives us. If the damper is to slow, or rises to low, or is tilted either way, you might get hammer-string contact at the moment the hammer strikes the strings. This too will sometimes get you weird tonal by-products. Sometimes the damper fools you by lifting late, and when you check with the key depressed, everything might look ok. When you press the key slowly and deliberately check for errors, there might be no problem. Then, suddenly, at the right key velocity the problem occurs, in fractions of a second, which is enough to trigger the problem.
   
   (The other problem related to nr 2 is of course of the damper makes constant contact with the strings when it's supposed to be clear of them, that is when the key or the sustain pedal is depressed. But that should be easy enough to spot)
   
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3. Third, is maybe the easiest to spot, and that is when the damper is released back onto the strings in an uneven fashion, and rests there tilted in some way.

All of these three hammer/damper related issues are real nuincances to the piano player. I successively through the years started to do these corrections myself, before and after concert rehearsals. Some of this I can now fall back on when I take my first steps into regulation of the instrument.

Check these out and see if any of it helps. As I told you before, I hope the craftsmen who have "been there - done that" might give their experienced opinion as well.

You can find out for sure if its the hammer or not.

Press the sustain pedal and hold it down, gently press the hammer against the strings with your hand and pluck all two or three strings with your other hand. If the hammer isn't making contact with all of the strings then the problem could be hammer to string mating. The strings may also need to be leveled which could have an effect on the dampers.

Also make sure there is enough lost motion in the sustain pedal. Without touching a pedal strum your finger nail over the strings. There should be no sustain from the strings with dampers.

A spoon could have been accidentally bent while the action was out of the piano.

Absolutely, that's another of those potential problem zones.

And while we are at it, I played a Steinway C a year ago that had the sostenuto bar catching roughly half of the dampers, and left the others to God´s mercy (not necessarily any irony there, it was a church concert). The laymen of the church recently moved the SW C from another congregation venue into the church itself, but it was so heavy that they took it into pieces at the transport, and put it together back themselves...:).

Starting the rehearsal there was no sustained sound in the A0-A1 octave, as the dampers didnt rise at all. half of the hammers aspired on the neighboring strings, the una corda damped the wrong strings, you name it.

Now I assume that you Kawai (pianoannoying) has a felt damper pedal as the middle pedal, but anyway, it might be a good thing to remember in the future. It could be worse, hahah

Most of the subtle problems that I've ever encountered on grands have been with the sostenuto lever tabs interfering with the dampers.

It is a great idea for anyone getting started as a tech. to learn about diagnosing sostenuto pedal problems. Uprights with sostenuto pedals can be even more challenging sometimes.

If I missed it, please excuse me, but is this an upright or a grand?

That's a good question Dan. At first I thought we were discussing an upright problem and then it gravitated to grands.

WOOOOPS.

I have just started to read all of the posts. of course I made a big mistake not mentioning that i'm talking about upright piano.
I guesss it is the problem of the "beginning technicians" (which is a degree that I don't even deserve... ...yet )

Next time i'll be more careful

It sounds to me that it´s a problem of the striking lenght. Probably you changed this lenght by removing the action several times. Of course this should not happen when removing an action, but obviously it did happen.

How comes the action back in the piano: is it easy to bring it back? When you tilt it back in the piano, can you lift it up before it hits the rods that hold the action (sorry, don´t know the English word for these rods. I am talking about the rods that have brass screws to hold the action)? If so, there should also be a problem with lost motion that was absent before. Perhaps the action was held only by the brass screws instead of sitting on it´s base before you removed it the first time. In this case you should have negative lost motion now.

Gregor

PPPAT, I'm working on your suggestions, hoping one of the three are the right explanationd.
i'll update when having results.

Thanks a lot.

You gave me a great idea now!

I'm not near my piano so I can't check... but the thing is that i really brought all of the hammers closer to the strings!

My piano stands in a ao small room, and it is a piano that plays so loudly, enough to be heard at a big concert room, and this tiny room makes it worse.
moreover, i have a special problem with the harsh sound - so so harsh!!! (If am I right, I have to do voicing procedure?)

----> so, in the bottom of the piano I released the screw of left pedal (the one that softens the sound by getting all hammers close to strings...) i just made it closer without having to pedal it.

MAYBE THATS THE PROBLEM! I can't wait to check...

Piannoying, you don´t seem to be a piano technician and I am no English native speaker, so we seem to have some communication problems. I was not talking about the hammer distance (travelling distance) but about the striking lenght. I mean the point where the hammer hits the string. This point can be higher or lower on the string, measured from the agraffe or the line that determines the speaking lenght of the string. If the striking point is higher or lower than supposed to be (designed by the manufacturer)you have a wrong striking lenght which can produce the effect you described. Subtile changes in striking lenght are enough to make problems. Therefore my idea was that such a change could have happened to your piano. But the question is why this should have happened. I wouldn´t expect such a failure in a Kawai piano. But who knows who scamped around with that piano in the past. I saw pianos where the action was held indeed only by the brass screws instead of resting on its base. So, when you dissolve the screws the action falls down on its brackets which causes a change of the striking lenght. That idea came to my mind because you mentioned that the problem began when you removed the action.

What you did with the left pedal is just reducing the travelling distance and should have no effect like you described. To be honest, I believe that the left pedal has no audible effect at all. The theory about the left pedal is this: shorter travelling distance = lesser energy at string hitting = softer tone. But I don´t hear any difference. What you did with the pedal causes lost motion, nothing more.

Gregor

Of course i'm not a technician.. I mentioned that I "want" to be. That is my wish. I know I'm doing many things wrong, and I'm taking risks influencing bad on my piano value. but it worths it for me, to fulfil my wish.
(I hope that the fact that I'm only beginning won't make all the great experts here to belittle my issues i'm dealing with)

Indeed, my Kawai is not first hand. There is logic in saying that Changes were made until it got to my hands. Hopes not.

Piannoying, you'll get feedback from more than one source here. There's a lot of combined experience. I wouldn't limit myself to just one person/source. Have you considered taking a course or reading Reblitz?

yes byronje3, I'm reading Reblitz. Its impossible to get courses here... Small Israel...