Piano World Home Page Forums Our Most Popular Forums Piano Forum Grand aftertouch - a question for pianists and dealers

A question came up in the technical forum the other day about a particular piano (a newish Sauter grand) feeling heavy and tiring to play. One suggestion was to reduce the aftertouch.

My question to those of you who worry about these things is how much aftertouch do you like. How much do you want if you are a pianist and where would you set it if you are a dealer prepping a piano.

By aftertouch I mean the distance the key travels in "free fall" before reaching the cushion after the action has done its work. As far as I can tell the normal range would be 0.50-1.50 mm.

One teacher said he had put thicker punchings on the front pins of one of his pianos to reduce the aftertouch. This made it far more responsive (which you might expect) and feel heavier (which you might not). Another wrote that a piano with more than 3/8" or 1 cm key dip would feel heavy and tiring to play.

I ask because I need to reduce the aftertouch on my grand and it would be really interesting to know what people prefer - none, a little, some, a lot?

The technician where I work has a tendency (perhaps the lack of regulation maintenance, combined with institutional use) to have almost zero aftertouch in the grand actions I regularly play. I HATE it - I feel like I'm playing into a brick wall. By the same token, I dislike the feeling of an overly distinct letoff.

Techs: aren't the hammer line and aftertouch related?

Well, yes... more so is the let-off.

To improve a piano which is "feeling heavy and tiring to play", I would first investigate if there are friction problems and then do a complete regulation.

I personally prefer a very responsive and light touch, so my piano is regulated that way (less blow distance, a bit less key dip, etc.) - but everyone is different. Many prefer a heavier touch and as much volume as possible.

Grand regulation is a somewhat complex and multi-faceted project some techs are really good at - while many are not.

It often is "fiddly" type work few enjoy and many don't.
It can be done "quickly" like setting only hammer drop or take longer including adjustments to repetition springs and more.

It usually takes into consideration questions of after-touch for which there exist different ideals.

From my experience the tech is of more importance here than the piano. Hours: 2-6 depending on job.

Again,among those I found consistently most satisfying results if the tech can communicate well and perhaps is also pianist him/herself.

Unfortunately while many can "talk" about the issue, few are able to actually deliver the goods.

Re used Sauter: this would be a 'joy-project' to do.
Extremely stable Renner action, nice to work on.

best wishes,

Norbert

Greetings,
Lack of aftertouch usually makes pianists feel like they are hitting a barrier when they play. Even at speed, there is a cushioning effect of the dead space after escapement. Without it, pianists have to play the key all the way down to insure that the note will escape. In this case, the pianist will hit the felt punching at the full velocity of the keystroke. My customers all consider no aftertouch to make for a lousy feel.

Too much aftertouch make for a vague feeling in the keys at softer playing levels. Pianists complain that they really don't know where the bottom is, and that they are "swimming in the keys"

Aftertouch is the related to key dip, but there are limits. Usually, aftertouch will be between .O25" and .050". This amount is subtracted from the key dip to determine how much of the travel is used for propelling the hammer. Keys on grands will move between .375" and .420". If they go deeper, the sharps will be below the naturals when depressed, and nobody likes that. The geometry and blow distance will determine how much propulsion you need.

If one simply reduces aftertouch on an existing regulation, the checking height will decrease, (key is not moving as far and the back-check is not coming up as far). This will slow down the repetition speed, which is determined by how fast the key rises and how far it has to rise to allow the jack to reset. The lower the hammer is checked, the farther the key has to come up to allow the jack to reset. On the opposite side of the equation, increasing aftertouch on the same regulation will, after certain point, will also slow down repetition, because it requires the key to travel farther up to allow resetting.

For a given blow distance, I think the optimum aftertouch will position the jack, at check, halfway between the near side of the knuckle and the mortise stop felt.This can be cheated back and forth a small degree, but with no aftertouch, any wear and compaction in the action will interfere with escapement.
Regards,

Thank you very much for contributing your expert opinion to this thread, Ed.

+2

The silent majority seem be to happy to leave aftertouch on their pianos to expert technicians. Zero aftertouch is OUT, unless one aspires to play like Horowitz or Gould.

Dr Foote says aftertouch is usually between 0.025" (0.6 mm) and 0.050" (1.2 mm) and I think he would prescribe 0.040" (1 mm) for most pianos.

His point about a reduction in aftertouch reducing repetition speed was new to me. It all started to become clear when I drew the arcs of two circles describing the paths of a hammer tail and the tip of its backcheck. I am still thinking about the spring pushing up the repetition lever and the knuckle of the hammer in the nick of time before the jack arrives on its way back.

The last eighth inch of hammer travel appears to be an elaborate timing exercise not only for the technician but also for the pianist.

We seem to adapt almost instantly to an adjustment in aftertouch. How do our fingers learn to stop or slow down in the split second after we hear the notes and they hit the cushions?

Greetings,
In fast repetition, the hammer doesn't move upwards, all the motion is in the key. You can observe this by playing a note in check, then quickly removing your finger from the key. You will see that the hammer doesn't move anywhere but down, and only after the key is up. High speed films show this more clearly: the hammer stays put while the key returns high enough to allow the jack back under the hammer.

We test spring strength by observing the rate of hammer rise on release from check, but we have to anchor the key to see it do this. If you just let go of the key, the hammer doesn't rise, at all.
Regards,

Not sure what the reference to Gould and Horowitz regarding aftertouch comes from. The specs I have seen for Gould's regulation quoted in one of the Gould, books presents a physical impossibility, geometrically. Those specs have been challenged by techs with first hand experience working those pianos...can't believe everything you read.

With a .375-.39 dip, I like the balance I get with .04 aftertouch. A little more is ok, but it quickly gets sloppy for me past that. Too much less than .40, and it feels much heavier, especially at speed. No aftertouch hurts.

The feel of the let-off bump event, is, in my opinion, a different parameter. A minimized let-off bump, one which is crisp, but minor, feeling of resistance, is one of my definitions of a great playing action. This is achieved both in the design stage, and in the regulating stage. When regulating, synchronizing the first perception of the jack tender hitting the let-off button, with the first perception of the drop screw hitting the rep lever leather, allows let-off, to be experienced as a single, precise, quick event. Non-synchronized let-off, extends the time we are perceiving the let-off event, and makes it feel mushy. Add that mushy let-off to too much aftertouch and one loses quite a bit of the clarity I am looking for in a well designed, well regulated action.

Ed,

Thank you for the explanation but I am finding it difficult to envisage the high speed video (frame by frame position of the jack and knuckle when the action is in and out of regulation).

On my piano I can see the hammer moving with motion of the key. After a hard blow, however, the hammer comes up after a slight movement of the key releases it from the backcheck. After that the hammer moves with the motion of the key.

Would you please clarify how the backcheck and the repetition lever should work to allow the jack to reset as quickly as possible as the key moves up ?

Thank you.

Greeting,s
If you play a note that puts the hammer in check, then slide your finger off the end of the key, allowing its free return, you will see that the hammers maintains its position and then drops. At no time will it lift. This mimics the fast repetition resetting of the jack. If the hammer were to lift as the key rises, there would be lost motion introduced between jack and knuckle in fast repetition because both components would have to decelerate at the same time and rate to remain in contact. Given their vast differences in mass, that would not happen.

"After a hard blow, however, the hammer comes up after a slight movement of the key releases it from the back check."
In this case, you are anchoring the key, preventing its upward movement, so the spring WILL lift the hammer, (it's tension has to go somewhere, however, fast repetition is achieved by the pianist releasing the key as fast as possible. You may be able to move this fast. Test yourself by observing the hammer as you lift your finger as fast as possible without sliding it off the end of the key.

The spring increases the speed of the key's return, allowing the jack to reset before the hammer has a chance to move. The inertial resistance the hammer,(a function of the moment arm between flange pin and hammer weight) on the cocked repetition lever as the tail is released from check is sufficient to do this without the hammer moving. The speed of repetition is dependent on how far the key has to come up to allow the jack to reset,(checking controls this), and how fast it moves to reach that point.

I will add that the key's return speed is virtually the same with a spring set at at smooth fast rise as it is when the spring is so strong that it throws the hammer off the key. The excessive spring strength doesn't add usable repetition speed to an action that is properly regulated, but it does increase escapement resistance. Perhaps at the very top of the piano, where the keys are quite light, there may be added speed, but even with a softer spring, higher checking is far more of a factor.
A low checking hammer will cause slow repetition, regardless of how strong the spring is. A very high checking hammer will allow fast repetition with a slow spring. I like to set the springs as strong as possible without being able to feel the recoil in the key. On stage, I go a little stronger than that for insurance.

hope that helps,
Regards,

Thank you taking the time to explain that again, Ed. I have yet to see it put so clearly elsewhere.

It was the hammer hanging in position for long enough for the jack to reset that I had to grasp.

Pennies can take a lot longer to drop than piano hammers.

Hi Jim,


I was just covering myself in case someone likes minimal or no after touch. Franz Mohr, reportedly had to remove all the aftertouch from Horowitz's piano - does it say that in his book, My Life with the great Pianists? Kevin Bazzana's book said Gould wanted no aftertouch but Ghyslaine Guertin quoted him as finding a relationship to depth of touch to after-touch on his Chickering which had to be modified for a Steinway.


I believe my 1905 piano is now at .360" dip and nudging .04" aftertouch. Its design goes back to the 1880s when dip was less than today so they say. It seems lighter than before when dip and aftertouch were about 0.03" (0.8 mm) deeper. Downweight is about 53 grams for the central keys, upweight about 33 grams.

Why do you think that the action feels heavier when aftertouch is rather less than 0.04"? Is it due to the slower repetition, striking the cushion harder, too little time between hearing the note and hitting the cushion, or something else?

Not sure...could be a follow-through thing. After an exertion, say like swinging a bat or a tennis racket, or throwing a ball, the energy seems to jamb if the muscles aren't allowed a cool down moment at the end of the stroke. Could be that the aftertouch as an inertia driven movement allows the muscles a millisecond of relaxation before the next exertion.

With too little aftertouch, escapement feels incomplete. This sensation makes you want to keep pushing the key deeper and this quickly feels very tiring. The primary regulation point for aftertouch is via hammer blow.

Greetings,
I played that piano at the Steinway factory before the action was de-regulated following his death. My former teacher was there in a technical capacity and told me that he had been instructed to set the action back to regular specs. He did, but left the fifth octave just as Horowitz had played it. There was aftertouch, but less than what I would have wanted. The let-off was as close as possible without blocking, which may have reduced the aftertouch. The blow was near 1 3/4", so the dip was less than you would expect on a D. Very light action, very brittle sound, which was a function of hard hammers and dampers that were lifting just before let-off.
Regards,

There wa an unexpected after touch to this thread on Wednesday. BBC Radio 3 happened to broadcast Horowitz playing Scriabin, Vers la Flamme. I do not know if this was "that piano" but enjoy.

Most Digitals seem to have 0mm of aftertouch and I know I hate that! It beats up my arms really badly! I have never played an acoustic with 0mm of aftertouch, but I bet it would bother me the same way.

There are many differences between my digital slab and my concert grand. But aftertouch doesn't make the list of ones worth mention. Maybe I just got lucky and happened to get a deal on a digital that has it.