Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Question regarding touch of my new GX3

Hello,

On Thursday I received my new Kawai GX3 which was uncrated at my home.
It was not prepped by the dealer nor is it going to be unless I hire my own tech.

After maybe 7-8 hours of practice I think I have diagnosed my main issue about the touch.
For most of the dynamic range, the touch is excellent and responsive, but when I try and play at the very lowest of the dynamic range (something like PPP) I notice that once the key is pressed 2/3 of the way down, it engages what I assume is the escapement/repetition mechanism where the hammer drops down a little. This causes noticeably more effort that's required in order to get the key the final 1/3 of the way down
For anything louder than PP/PPP this is un felt and the way down is seemless, but it causes unreliable results when I attempt to play at the absolute softest volumes, because I use significantly less force and speed to attack the key, which sometimes happens to give me just enough momentum to get the key 2/3 of the way down, but at the last 1/3 of the way I sort of hit a wall and don't get a sound.

I'm convinced that if there's a way to make the entire down motion of the key feel the same, or at least feel almost the same, then my control over PP/PPP will be a LOT better.
Can this be achieved? If so how? What is the adjustment that would make the whole motion of the key feel more uniform rather than heavier at the final third of the way down?
Thanks!

Edit: I have tested both with and without the damper pedal pressed and it feels exactly the same so the problem has nothing to do with the damper mechanism I assume.

There are several points when parts of a grand action will change quite a bit: When the damper begins to lift, when the repetition lever engages, when the jack hits the let-off button, and when at let-off as aftertouch occurs. There may be others depending whether the action is improperly regulated. This is normal.

Playing softly is difficult because there is escapement: the key does not push the hammer all the way to the string. The hammer has to be moving fast enough at let-off to have the momentum to hit the string after the key is no longer pushing it. This also is normal. The best you can do it to make sure this is fairly uniform.

The best way to play softly more easily is to voice the piano so that it is softer overall. This can make it more difficult to play louder, but that is usually a good thing for home pianos. Unfortunately, this is the opposite of what you want for a concert performance, and that is generally how pianos are advertised. That is the dilemma!

It's escapement, very careful regulation and lubrication can make it better but it will be there, your piano should be voiced down, it will be the most effective method to make it easier to play ppp.
Most pianos have this problem, but big manufacturers are not willing to change anything in design, or maybe most pianists like bashing the keys and don't give a f about pianissimo, hard to tell exactly...

Your letoff may also be too wide. Letoff is the highest point the hammer will reach before it drops, which you can see if you push the key very slowly. The hammer will drop a little right after you feel that "bump" in the key. The gap between the hammer and strings right before the hammer drops should be 1/16" or about 1.5mm. This is measured from where the string indentations are on the hammer felt, up to the underside of the corresponding strings, and is know as the letoff distance. I use a 14 gauge wire bent in an L shape as a feeler and move it front to back under the strings when the hammer is in its highest position to assess the gap. If your gap is double this amount or more, it may be the cause for what you're feeling. Easy fix for a tech or even yourself if you have an icepick or something to adjust the letoff buttons. There are plenty of videos on YouTube that show you how. But if it's your first time, maybe call a tech in to do it. If you watch how it's done, you'll know how to do it next time.

If this is a new piano, your rail bushings may also be too tight. Playing them in may fix it, or you may need a tech to ease them a little. Also not hard to do with the right tool.

In the lingo of computer programming, it's not a bug, it's a feature!

What you are feeling is commonly called the "bump" of the grand action. Perhaps yours is imperfectly set up, and that might be what is causing you grief, but the sensation of a clearly discernible point of contact somewhere before the key reaches the bottom of its travel is, in fact, a desirable trait of well regulated grand actions.

Most of the people who have influenced my understanding in regard to this would say that the repetition lever should contact the let-off button at exactly the same time that the toe of the jack touches the regulating button. From that point on, there is a short distance over which the jack is sliding out from under the knuckle. In that interval, two springs are also being compressed -- one for the jack, and one for the repetition lever. At the end of this short interval, the jack is out from under the knuckle, and the hammer drops.

Some technicians and players prefer to have the knuckle lubricated with teflon or some other dry lubricant, so that the tiny bit of drag produced by the jack moving against it is reduced even more. Others prefer it unlubricated.

Players with whom I am in dialogue describe the properly regulated "bump" as very much their friend, and as a true benefit in achieving control at soft dynamic levels.

Since you've already fixed the dampers, you might be inclined to lubricate the piano's yourself if you feel comfortable taking the action out and taking the action bracket off. I would hit the hammer knuckles and front and center key bushings with PTFE powder. Howard Pianos has some how to videos on YouTube on piano lubrication that covers the procedure. Many new pianos have tight key bushings that benefit from easing or lubrication. Of course a tech can do this also.

Ask the piano tuner about the action regulation when your piano is tuned. Having been shipped across the ocean, the action regulation often benefits from being touched up. The technician can check the jack angle regulation, the letoff, drop, and repetition spring strength. All of these can contribute to making it more difficult to play softly.

Thanks everyone for weighing in.
I do realize that there are several other factors that can help with very soft playing such as voicing and the letoff adjustment but I believe they are all secondary since they are not responsible for the issue I have described.

I think that IF X momentum = enough momentum to get the key down 66% of the way to the keybed, but not enough to push it down the final 33% of the way (ie: the 'bump' as a couple of people have called it), then this is probably the first thing that I need to address, or I will never be able to reliably and consistently get a sound of of the piano whenever I play in the PPP range.

My question is, which adjustment exactly can make it so that the pressing of the key will feel like 1 seemless smooth motion rather than feeling like 2 separate stages, during PPP playing.
Is it perhaps the spring of the repetition lever that needs to be weakened to achieve this?

You and your piano just need time and familiarity to get used to each other.

That's right of course, but are you implying that there is no adjustment that will make the transision between having the key pressed 66% of the way down and 100% down more smooth and seemless during PPP touch?

It may be possible to get the action MORE smooth and seamless, by regulation and lubrication, but it is not possible to make it COMPLETELY smooth and seamless. You wouldn't like it if it was. The added resistance at set-off is an important part of tactile feedback. I'd like to second BDB's comment about giving the piano more time.

Thanks David.
I think that having it MORE (rather than COMPLETELY) smooth and seamless might be all I need.
Yes I will give it time but I know myself well enough to also know i'll never fully come to terms with the degree of resistance that the 'bump' is causing until I lessen it.

Could you be more specific about what part exactly should be lubricated or regulated in order to directly affect this?

Really just what others have suggested, and probably your technician should do it. Many piano regulating tasks are fiddly and time-consuming. Look at and if needed adjust the jack position in relation to the knuckle core, lubricate knuckle buckskin with Teflon powder, check timing of damper lift. With regard to giving the piano time - it's not just a matter of you getting used to the piano; a new piano may need to be "run in" like new cars used to require.

GnGEmpire - are you perhaps used to playing on a digital keyboard? Digitals don't have the bump that has been described here. In my opinion, they feel horrible, even with weighted keys.

Bobrunyan I have slightly gotten used to my digital piano during the 2 month window between selling my upright and waiting for my grand. It was not a pleasure at all but i can appreciate the 1 advantage it gave me with the key motion being all the same, in that sense i had to plan how i approach the key less than I do on the grand when trying to get a whisper out of the piano.
But it was aweful in every other sense and the grand is an infinite step up.
On friday i have the first tuning, I'll see what the tech thinks about the 'bump'

If you want easy and reliable control at lowest dynamics, voicing is not secondary!

GnG, can you go to the piano store and try some other quality grands and see if you feel the same issue? If you don't feel it on other pianos, then something is probably out of regulation with your piano. We can surmise from afar, but to a tech working on your piano, the actual cause should become obvious. Given the newness of your piano, I'm sure it's just a matter of making some regulation adjustments. There is nothing in the M3 action that would inherently cause the transition to be any greater than on another piano's action.

Another thought, what if I were to have the hammer blow distance shortened a little (hammer resting/starting point being closer to the strings).
It might make it so that even if I get 'stopped' by the bump during PP/PPP, the hammer would have already hit the string earlier and I may get less silent/ghost notes.

Does that make any sense? Or perhaps by doing so I will just be moving the point where the 'bump' occurs to happen earlier also? (for example at 50% of the key depression rather than at 66% (which would negate the result i'd be trying to achieve)

No, it's not how this works, bump is escapement, it has to be where it is, it can't be set much closer because hammers would block on the strings and you wouldn't get a sound and if set much further from strings, hammers would not even hit the strings on soft blows. It should be set as close as possible for better ppp performance but this itself won't change that bump. Changing blow distance doesn't change escapement timing but reducing it will make the piano slightly quiter but then also keydip has to be reduced and you can't really reduce it much because action would not fit in the piano. In upright piano left pedal is doing exactly that, reducing blow distance, so you can imagine how this would work.

My advice is stop overthinking it and get a tech and tell him to make escapement closer and less pronounced and voice that piano down.

Thanks ambrozy, i'll see what the tech who's coming to tune the piano tomorrow thinks once he sees and feels it