Piano World Home Page Forums Our Most Popular Forums Piano Tuner-Technicians Forum Why and why not adding lead weight to key

Its general thought the heavier the key, the better touch in my city. People believe expensive piano should have heavier key. Imported German piano, grand piano, all added lead in warehouse. For dirty old Yamaha, adding weight to make faster repetition. Music teacher suggest student to add weight to make finger stronger.

What's consideration of adding weight? What recommendation should give to customer?

I always thought German pianos had lighter actions

Comparatively it has been said that US made pianos had a light touch, and European pianos a little heavier. The thing is the weighing of the key only should be to offset and balance the weight of action/hammer. The resulting response and feel is a matter of leverage ratios and how tight the pinning of action centers is. Touch weight metrology looks at the various weight measurements (up weight, down weight) and attempts to determine friction. A piano that has been well regulated and touch weight analyzed and adjusted to make as even a curve as possible up the scale is a marvelous thing to play. Strangely enough even some of the bigger name piano makers don't spend as much time as one might think getting the playability and touch dialed in.

SMHaley:

Making even curve is marvelous. Then weights different for black key and white key?

For weight analyze, the down weight and up weight only measure static force. Actual playing is dynamic. Hitting the key with higher velocity, the higher reaction force. The point touch the key also affect weight. EG, playing A flat major chord is a lot heavier than C maj. chord. What's best method for weight analyze?

My experience is mainly from upright piano.

IMHO, this is complete and utter nonsense--I place the original blame directly with S&S. There was a period of time where they increased hammer weight so dramatically, and in turn needed to balance out that weight with extra mass by installing crazy amount of leads into the keys, that the pianos became impossibly heavy and difficult to deal with. Pianists got used to this heaviness, piano technique was modified to fit the approach, and other companies followed-the-leader. They have since backed off of the excessive hammer weight, but since pianists became accustomed to that kind of feel, it is difficult to go all the way back to the way that it is supposed to be.

A pianist should NEVER have to fight with a keyboard; a keyboard should work for and with the pianist.

FYI, there are three kinds of heaviness in the keyboard: 1) leverage weight (i.e., the weight of the hammer at the end of the lever--this weight is more or less consistent through the key stroke), 2) moments of inertia (i.e., the leads in the key and the weight of the parts--this weigh is felt more with faster accelerations of the keystroke), and 3) balance weight (i.e., the amount the entire keyboard is set out of balance--higher amounts of out-of-balance helps with repetition, but the starting weight of the key movement feels proportionally higher). Friction in the system is a 4th perception of weight, as is the weight of the dampers (5th), but these have other important functions, so they should be last to be toyed around with.

With that said, it is not a matter of simply adding key weight; the perception of weight for a pianist is complex system that need to be properly balanced as a whole.

SMHaley, US pianos are know for being heavy and European for being comparatively light--you have it completely backwards. It is also why the OP mentioned that in their part of the world weight is usually added to make the European pianos heavier. They are, presumably, adding weight to the back of the keys, which would make the entire system heavier [in terms of starting force] and also increase repetition (i.e., since the system is more out-of-balance).

Greetings,

If adding weight to the back of the key increases repetition speed, there is something dramatically wrong with the action. Repetition speed is determined by how fast the jack resets, which is dependent on how far the key has to move up, and how fast it moves. The speed of the key's return is more dependent on the spring strength than anything else, and the amount of weight required to appreciably change that would make the piano unplayable.
Regards,

A443,high inertia keys have 2advantages :

Stronger tone

Strongest power sensation


Easier rebound of the key.

So unless the leading is really extreme, it can be managed, of course reducing the nuances possible.

I happen to add lead to reinforce the tone (the power of the catapult)

Not that I would do so on a fine piano (plus there is more effort on the balance hole) but as well on a tired soundboard where it gives a "permanent power" sensation, as on a small grand where the basses where "evened" in power with the rest.

If is easy to experiment with screwed leads under the keys.

Surprised the first time I have seen that overloaded instrument that was way more playable I expected (A lead screwed under any key)

Not elegant, I agree.

Adding back weight have been a trend for a few years about 15-20 years ago, or making the actions stiffer.

The added mass have proved to be anti pianists since then, as what you manipulate is the hammer, not the key.

On verticals there are yet lead at the back, because of repetition, but also because verticals have little inertia if any, compared to grands.
But the inertia at the key is not perceived during acceleration, more at the beginning of the stroke.

While it is true that the resetting of the jack is the primary consideration for increased repetition, and the repetition spring is an important part to the double-repeating action, most pianist rarely take advantage of this in-the-key repetition feature. A pianist's perception of repetition is more dependant on the return speed on the key. When the keys aren't able to constantly stay in contact with the pianist's fingers during a dribbling kind of motion (i.e., mostly at the top portion of the keystroke: be it one staccato or multiple repetitions), the pianist will sense that the action as sluggish and unresponsive. <---that has nothing to do with the repetition lever or the spring, but instead is a function of the key not returning fast enough (i.e., not being enough out-of-balance enough: aka the down weight is too little).

If one were to take a conventional S&S--which currently has significantly heavier hammers that what earlier generations of pianists performed with--and then set the down weight to 70g, for example, it would indeed make the piano seem unplayably heavy!!! However, the keys would now return much faster and stay more connected with the quicker finger motions of the pianist. A quick key return is necessary for controlled repetition, either in or out of the key, so the system has to be balanced else where.

One could lower the action ratios, but this will also reduce the overall hammer speeds; the solution to making the entire system work properly is to reduce the overall hammer mass [or move the mass closer to the center pin]. This is not a new concept, this is how piano actions were originally designed and developed to function. There also happens to be other significant tonal benefits, especially in the capo section, with increased range in dynamics, louder sound outputs, better control over the softer dynamics, significantly better sustain and singing quality (i.e., the hammer acts less like a damper over its own weight), and reduced impact noise for the wooden hammer core/shank. The tenor and bass section also benefit tremendously by being able to control slower key speeds (i.e., softer dynamics)--which is extremely beneficial to voice between the registers (i.e., bring out the melodic line by suppressing the middle voices)--as well has also having much louder overall sound outputs.

Perhaps I do... Although in my personal experience I found that well maintained M & H, S&S NY, to be lighter than the well maintained Bösendorfers, Grotrians, Bechsteins, and Blüthners I have played. Yamaha's and Kawai's varied. If it is indeed backwards then my own experience only reinforced it.

European pianos tend to be voiced down more in the US that in Europe, and consequently psychologically 'feel' heavier with the resulting lack of power output, lack of impact/attack, and dullness. Perhaps you were responding to this...

Mmm, no. In all but one case the European instruments were in fact voiced on the bright side - more than my preference, and the US instruments perhaps a tad wooly. I'm usually quite aware of the feel of the action separately from the voicing.

Even though I've developed an excellent understanding of how different weights throughout the action respond to different action geometries, and how this affects the overall feel and response at the keyboard, I still have to actively 'turn off' much of the audio/sound information I hear from the piano when I am testing a piano out (i.e., when the hammers are over/under voiced). As voicers, we have trained ourselves to correlated physical motion with the resultant sound, but when evaluating the touch and responsiveness of the action, this mental connections needs to somehow get turned-off or temporarily ignored. That is not so easy to do: I use earplugs to focus more on the actual touch response. ;-)

Olek-
If you want more power - stronger tone - why not weight the hammer?
1/2 gram of brass or lead rod in the moulding does wonders.
It will make your touch heavier by 5 or six times the 1/2 gram and it is easier to do.
Also, the heavier down weight will be combined with a increased upweight of about the same amount minus a little friction making the action faster.
This works only if your action is not too heavy already.

Greetings,

I totally disagree. The pianists I work with gauge repetition by how fast they can repeatably play the note. The greatest factor in that is how high the hammer checks, since this determines how much key movement is required to reset the jack. The resetting of the jack is entirely dependent on how fast the key moves(spring) and how far it has to go (checking distance).

The repetition spring lifts the key for repetition, it does not lift the hammer. You can see this for yourself if you play a note, and then, while the hammers is held in check, slide your finger off the front of the key. You will notice that the hammer doesn't move until after the key is up, and at that point the hammer drops, it DOES NOT rise. The additional mass does not increase the speed of the key because the speed is determined by the spring's action against that mass, and the more of it there is, the more work is expected of the spring to lift it.

Another illustration is to play two adjacent notes, and then let one of them go off check. If you release both keys at the same time, the key without a compressed rep spring,(the one that is off the back check). is lethargic in comparison, and no amount of usable weight on the back will cause it to catch up.

My experience is that the more mass there is in the key, the slower the action will be. Gravity is fast, but nowhere near as fast as the spring. I have been asked by some faculty members to weight the actions for their "concert practice". Putting jiffy leads on the back made the action heavier, but invariably, the feedback was that it lost some rep speed. Putting a 1 gram clip on the hammer shank caused the same amount of "heaviness", and invariably was felt as faster.

The other consideration is that the heavier key will bounce more, and under fast play, this bouncing can upset the resetting.
Regards,

Gene Nelson...because additional hammer weight does not result in more power, or a stronger tone. More weight will change the partial distribution by dampening the higher partials and result in increased contact times, but this can reduce the total power output, especially in the capo section, as the hammer then also functions as a damper.

More power comes from faster hammers impacting the strings. It depends on the action geometry, but essentially any hammer+shank weight over 5g at the point of contact with the string begins to reduce the maximum 'terminal velocity' of the system.

5g is not very much at all...

Yeah, assuming you just weight the hammers and ignore everything else.
Voicing is the key to solving hammer string contact time in this case.
I know - Ed has written much about light hammers and I understand the concept but heavier hammers move the string more efficiently and if done well will get more out of the string.
Light fast hammers in my opinion give a thinner tone.
F=MA.
Personally I will select the heaviest hammer I can get away with and adapt the action to it.
This may mean changing the spread or moving key capstans or removing/repositioning key leads or being happy and able to cope with shorter blow distance.
Less led in keys + heavy hammer (good quality hammers like Isaacs that have not been filled with lacquer) &good action geometry = maximum power and tone potential.
Certainly it would not make sense to weight up into the treble where excessive hammer string contact times could not be compensated for. It may take a bit of experimentation.
Also keep in mind that quality hammers play a roll in this.
More spring in the felt contributes considerably.
Hot pressed and heavily lacquered hammers I will avoid at all costs.

Oh, great, then I look forward to reading what Ed (Foote/McMorrow?) has to write about light hammers.

But, Gene Nelson, your assumption about heavier hammers getting more power out of the string (e.g., in the bass/tenor) is completely wrong--it is clear that you have never tested it. Try it out sometime and record/measure the difference. It is not a small difference: it is HUGE!

If you think fast light hammers give a thinner tone, then you have also never experimented with proportionally larger strike points. These two issues are interconnected and can not be confused or ignored.

Hammer voicing, and tension hammers are sadly not enough. They help, but they can only do so much...

Ed Foote, it is necessary that we learn to see the forest for the trees...

What you have said about the repetition spring and its interaction with key return is entirely correct, but even with the correct back checking height AND drop height, the spring can only partially accelerate/assist the key with its return from a dead stop--there is also a rebounded return where the key is bounced off the bottom of the cushion; the repetition spring plays no meaningful, if any, part of the key's return (e.g., staccato-like attacks, or when the fingers are pulled in for acceleration rather than being pushed straight down).

I know you know this, but the key-lever system is an out-of-balance seesaw--gravity works its affects on both sides of the equation. If the system is only 10g out-of-balance, the return of the key is very slow, just as it would be with a playground seesaw; the keys would not remain in contact with nor support the pianist's fingers on the return. Now, if you put the same system out-of-balance at 100g, it will be fast enough to always remain in contact with the pianist's fingers, no matter how fast the fingers are on the return. So the question is, what is the magic range that ensures the keys are always working with the pianist and never returning slower than their fingers are able to move? Have you tested it? Have you looked at/recorded key movement in relation to the return speed? Consider: many pieces use only the top portion of the keystroke [and with damper pedal], like in impressionistic tonal painting-like compositions--the spring isn't part of the action response in these cases; and 50g down weight isn't enough to keep the action responsive enough in these types of situations.