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beautifully voiced brand new piano, but needing serious regulation. This shows the notes that are sluggish to return to key level. One never knows when and where they will crop up. It is hard to believe that the factory let this issue slip by. Or anyone in the process let it elude quality control.
https://youtu.be/uk-aVrBceYc

As I said elsewhere, it may not have cropped up in the factory. It may be a result of changes in humidity.

The dealer, then, should have regulated.

Was the piano good when you bought it from the dealer? How long has the problem been going on? How long ago did you buy it?

What brand is it?

The ideal conditions are a constant temperature of 20°C and humidity between 45% and 70%. Large swings in humidity should be avoided and it is advisable to purchase a thermometer and hygrometer to monitor conditions. The dealer has no control over your home. Berkeley is at 80% humidity right now. You get the humidity down in your home it will probably not be a problem.

It’s easy and quick to blame somebody other than yourself for a problem because of a lack of information. Before blaming the dealer or their piano technicians do more research since you are not an expert in piano technology. A simple google search could have helped answer your question.

The piano had these issues prior to delivery that I noted.Voicing was amazing. Has NOTHING to do with humidity here in my home re: rebound issues. Purchase Came close to SIP so either the dealer will take care of.. Or my chosen tuner. Samick has been notified and is sympathetic. It is a Knabe, brand new, made in Indonesia--only here a short time..I think yes, one should flesh out these issues, as a warning to others. I tried some pianos at another establishment to make comparison--and interestingly with an Italian Made Schultz Pullman juxtaposed with a Chinese made Schultz. the latter was unplayable. Some of the Asian made pianos are not being properly regulated, period. I will exclude the Kawais and Yamahas that have decent regulation. Everyone knows that companies like Knabe are not the original Knabe. I will vouch for my Indonesian made Knabe on a tonal level. IT JUST NEEDS CONSCIENTIOUS AND COMPLETE REGULATION!!!! And frankly I don't need to be criticized for exposing issues...Your humidity fixation is inapplicable here..period!!!

I'm not sure why the need to voice a gripe publicly. If it was showing those problems in the store you could have told them you want it fixed before delivery. And then inspect it before a delivery day was set. Regardless of that, the dealer should still pay to have it regulated. Most likely a very simple problem and fix you're fussing over.

And I think BDB is most likely correct. Probably was working fine at the factory. I have heard that they make them with ulta tight tolerances, so any change in that could cause the problem you are experiencing. If it shows up intermittently, I'd be thinking also that the jack is high in the window or a weak rep spring. But only an onsite inspection will reveal the problem.

Enjoy your new piano.

-chris

You are a nightmare client with severe anger issues. Please warn your new tech of your issues and your superior understanding of pianos.

Lesson is not to buy a piano that you already knew had “graphic rebound issue”. That would make you a more reasonable person to deal with.

And you are a nightmare, Mr. Tim .Can't stand criticism. BYE!

Tim
Bless your heart! Could you possibly have anger issues?

Yes, I do have some anger issues with problem clients. It seems to make them more of a problem for me. Trying to work on it, but it is difficult.

With respect, Shirley, how can you be certain of this? Pianos react to humidity changes in many ways - increases in humidity can lead to sluggishness in various parts of the action. When I purchased my first piano, I was living in Oakland, CA, and in the first few weeks I had an issue with keys bobbling that weren't bobbling in the shop or when the piano was first delivered. As it turns out, the humidity in my home was more variable than it was in the piano shop. It was a simple matter of making a few minor adjustments, but it certainly wasn't the fault of either the store or the manufacturer.

Also, if you noticed this issue at the dealer, why didn't you ask them to rectify it prior to purchase?

And regarding the fact that the issue was there at the dealer - the humidity at the dealer could likely be very different than what it was in the factory. It seems exceedingly premature to blame the manufacturer when there are so many variables at play here.

When certain people feel victimized it doesn’t matter what anybody tells them. They will continue to feel and believe what they want to believe. They will seek out and find specific information that will confirm that they are a victim and disregard counter information. The people that try and convince them to be reasonable are part of their victimization narrative. I don’t think it matters what is said at this point about humidity. This person will believe what they want to believe. I just pray that whoever the tech is that gets hired to fix the humidity issues will not say the H-word (humidity) to this person. They will witness a meltdown.

I read in the other thread just now about how this person found many techs unreliable. To me this is another red flag. Not worth the risk of lawsuits of whatever to be blamed for problems outside of your control. Life is too short to deal with problem clients.

Why are you continuing to beat this drum? No one called you for a tech appointment. Just FYI, the OP is a well-respected piano teacher. Please let it go.

Step one, careful key easing and lubrication of key pins. Check the hole in the key shoe at the balance rail. Is the shoe too thick? There is a special tool for thinnitg the shoe inside the mortice.
Also lubricate the capstan and check that the wippen flanges are free.
If the action still feels stiff or heavy, try softening the hammer and damper springs cautiously.
Try shortening the blow distance and key dip.
From here it gets tricky. Can the action ratio be modified a little?
Bend the capstan wires to move them a little toward the front of the piano, and/or trim key punchings to reduce the key ratio.
This takes some sensitive work, testing sample notes and getting feedback from the player.
Also possible to reduce the hammer weight and keep the sound warm by voicing to soften the hammers.

Or incompetent techs.

I’m grateful to have a skilled tech without anger issues as I am comfortable referring all of my friends to him.

Greetings,
It is difficult to diagnose problems from a distance, so better feedback comes from a more technical description, and the piano owner can do more of a diagnostic test than playing the piano. My first guess is that the key-bushings have swollen, which is easily tested by feel. You need a slight clearance in the lateral key movement at the front. Check this by depressing, for example, the F and the A so that you can then grasp the G by the sides and move it from side to side. If you cannot feel ANY free-play, the bushing begins to be suspect. Next, firmly press the key from side to side as you move it up and down on the front pin. This is effectively "easing" the bushings, and if that is the cause, the key should instantly return to level, dependably. If you can remove the key-slip, this is more easily done. There may be friction at the balance rail, which is more difficult for the user to ascertain, but overly tight bushing there doesn't cause problems as fast as front bushings. Compare the lateral freedom of movement between the keys that are sluggish and those that are not and see if you can narrow the possibilities. This is more useful info for those of us that want to guess the problem!

While humidity can change bushings, it may be that the original factory work was not stable and a change of humidity caused a change in the felt. Lacking the skilled labor or time to mechanically ease the felt (by squeezing with special pliers, some brands are using chemical sizing solutions to shrink the bushings to the proper dimension. Felt, being a natural substance can sometimes expand just enough to affect performance. If the key bushings are not the culprit, I would want to take a measurement of the sole plate (the part of the key that the hole for the balance pin is in), and make sure it isn't more than 4 mm thick. You cannot do this without removing the stack, so check the easy things first. I you can remove your fallboard, key freedom can be tested by lightly hold the whippen up and lifting the key, letting it drop, and seeing if it bounces on the front when it lands. Do this with the pedal holding the dampers off the backs of the keys.

regards,

Because of comments you can read above, Shirley Kirsten has left this forum.
Those who care can find many examples of her teaching on her YouTube channel.
In the video she posted, observe the behavior of key C3 at about 24-27 seconds.