Piano World Home Page Forums Our Most Popular Forums Piano Forum Sustenuto Pedal problem - an update

Further update on this story (See previous thread : https://forum.pianoworld.com/ubbthre...o-pedal-strange-problem.html#Post3165975).

A Kawai technician, has looked at the problem, and determined that the problem involves use of the Sustenuto and sustain problem at the same time. The observation is that if sustenuto is going down as the Sustain is going up (requires use of both feet). I have managed to recreate this by playing some notes (its a borderline issue, so not all notes have this), and pressing both pedals alternatively using both legs.

I am wondering if this has been observed in other pianos as well.

The sostenuto pedal (almost always) needs to be fully depressed before the damper pedal. If it is only partially depressed, the tabs may snap past the sostenuto bar, causing a noise, and the notes on which snap will be held by the sostenuto. Timing is everything.

I did have a Hardman grand piano that had a damper pedal that lifted the damper levers only enough that the dampers were not engaged, and the keys would lift them further, at which point the sostenuto pedal would engage. It was the nicest working set of pedals I have ever run across.

Interesting.
You write that this problem occurs with "some notes".
Are they in the same 8ve on the keyboard?
Have you been able to identify a highest note and lowest note involved?

At this point, if the answers to the above questions are "yes", and the highest and lowest notes involved point to a compass of notes not the full 88, then I would wonder if there was some bend, or other irregularity in the rod of the sostenuto system that catches the uplifted dampers from held notes.

I'm also wondering about damper timing.
Can you see at what point the dampers start to rise when you press down on a key that gives your odd noise in conjunction with the action of the sostenuto pedal? Check that against a note which is not giving you the problem. If the lift point is different, it indicates a need for some damper timing regulation.

Just my opinion.
I'm glad your Kawai technician has been able to replicate the failure if not yet identify the root cause. Please let us know how things progress.

I only just learned this a few weeks ago. I was asking my tech about expected behavior and he said that if I depress both pedals at the same time, it could damage my piano!

Pressing them simultaneously might bend some damper wires, but you would have to press them pretty hard.

Interesting - I didn't think any combination of pedals would actually damage the piano!

The situation that triggers it is when the Sustenuto is pushed down, while the Damper is coming up. Even then, it only happens occasionally (maybe one time out of 10), suggesting that there is indeed a spot where the pedals are interfering with each other. Unfortunately to answer SEEKERS's question, it is difficult to tell exactly when it happens, both because of the low freqency, and because to see the movement of the sustenuto bar, The action needs to be out of the piano, defeating the purpose.

I have also noted that it only happens when at least one key is held and some notes are more susceptible than others - but that's to be expected due to small variations in the hammer.

When a key is held isn't the part of the action that raises the damper in contact with the damper? Then if the action moves sideways the damper may not like it?

Pianists seem to think techs should be able to adjust the piano, while techs say pianists should look to their technique. Who is right?

I agree with BDB's observation on the proper technique to use the sostenuto pedal. As a teacher at the university level I can tell you that (too) many students came to me not knowing what the sostenuto pedal does never mind how to use it properly.

Regarding checking damper timing, you check it with the action in the piano.

• You should press no pedals while doing it.
• Remove the music rack so you can see where the hammers come up under the dampers.
• SLOWLY press down a key - you should notice that the damper remains down until the key goes down some distance. According to Kawai's vertical action regulating manual, "the key should lift with the key when the hammer is halfway through its travel". I believe the spec is identical for most grand piano actions.

If there are significant irregularities in the point at which damper lift starts it means the damper timing needs to be regulated. I think it is highly unlikely that the sostenuto bar is bent or has some other surface irregularity that would cause a timing problem.

At this point, I'm more inclined to think your noise, as BDB wrote, comes from what amounts to improper use of the sostenuto pedal. Typically the way I use it is to press down the keys I want to sustain, press the sostenuto pedal, THEN add full damper pedal (or not) to blend the sound. If you have MANY notes held up with the sostenuto and you release it fast, it is likely you may hear some noise as the dampers drop back.

One last thing - looking at your signature, you have Shigeru-Kawai SK2. I must say that the damper pedals on Shigeru-Kawai pianos feel and work extremely well. I can't report on any noise or issues with the sostenuto pedals, because, so far, I have not had occasion to use such when playing an SK.

Just realised I mixed up this thread with a currrnt Una Corda thread in the Technician's forum.

The operation principle of the standard sostenuto pedal system requires that you not raise any damper with pedal or key when you are releasing the sostenuto pedal.

I have a screw stringer Mason & Hamlin 9' that has a sostenuto that can be release or activated at any time while playing and it will not clunk. It is the best sostenuto system in the world and I have never seen it on another Mason much less any other maker. It still works flawlessly after 130 years.

The first part of this video shows how sostenuto works:

Interesting video and I enjoyed seeing how the sostenuto works. I wish there had been some discussion of using the sostenuto with the sustain pedal. Looking at the video it would seem that using both at the same time would cause the tabs to push against the sostenuto bar and I could see how that might be a problem, either breaking the tabs or deforming them. Am I to conclude that the two should not be used together?

I think that depressing the sostenuto pedal while the sustain pedal is going upwards is best avoided. It's hard to control the outcome:

1. The dampers on the notes not being held by the keys that are depressed by your fingers have descended below the sostenuto rail before it rises: it catches only the dampers of the notes that are depressed.
2. The dampers on the notes not being held by the keys that are depressed by your fingers have not descended below the sostenuto rail before it rises: it catches all the dampers.
3. The sostenuto rail meets the damper tabs just at the moment they brush past it. In this case, depending on minute irregularities, maybe the rail catches some, but not all the dampers.

Case 1 is OK: the sostenuto pedal serves its purpose of holding only the notes you were playing, but to guarantee this effect it's better to simply make sure that the sustain pedal is not in use at all before depressing the sostenuto.
In case 2 the sostenuto pedal serves no purpose, since all the dampers stay raised: you could have simply left the sustain pedal down.
Case 3 gives an unpredictable result and might even damage the tabs.

I avoid the specific simultaneous action of the two pedals as described above, but apart from that there is no problem using them together, on a modern piano with a correctly regulated sostenuto. On some older pianos the tabs are rigidly fixed to the damper shafts, which can be problematic, but on modern pianos they are hinged so that the tabs that are not being held up by the raised sostenuto bar move out of its way when it is lowered.

Not quite what you had in mind maybe, but Graham Fitch has a lot to say about the sustain pedal ...

I think this is fair statement of the problem: The Sustenuto pedal - used on its own, does not have any issues. The issue (for me) started when when working a few 20th century passages where it make sense to use both at once i.,e hold a pedal point, and half or flutter-pedal the melody. This is tricky - which supports MRC's point - if its not done perfectly - it doesn't work.

But I've since then, I've had an opportunty to play on several other pianos (all of which are older than mine) - none of which have this problem - so I'm still wondering if this is something that can be addressed - though it is far less concerning than it was.

Thank you IAN - an Excellent and useful post!

Holding a pedal point with sostenuto while using half or flutter with the sustain pedal should not be a problem. Once the sostenuto pedal is down, you can do what you like with the sustain pedal. It's just the moment when you depress the sostenuto pedal that is delicate: to make sure you're really catching the notes you want, the sustain pedal should not be in use while the sostenuto pedal is going down.

There can be times where this has to happen fast: a split second too early and you catch notes you didn't want to catch, a split second too late and you miss the ones you did want to catch. But that doesn't mean you have to hit it! It's all about precise timing.

Agreed: Problem is, if your timing is off, then besides bad music, I get the annoying creaking noise (not a big problem anymore, just an interesting one).

OP, I had this issue, too, and would get the same creaking noise you did. The sostenuto pedal is used a lot in a few of the Ravel pieces I'm working on, as well as partial and full pedaling with the dampers, and, unpredictably, I would hear a crackling sound coming from directly behind the hammers. I could also feel resistance to the sostenuto pedal itself in my foot. There seemed to be no rhyme or reason to it, other than it always happened while I was switching from the dampers to the sostenuto pedal, or vice versa. After pulling the action and investigating the damper and sostenuto mechanics, I came to the same conclusion you did. You can have the dampers up or down when engaging the sostenuto pedal, but the sostenuto pedal is not designed or intended to be engaging while the dampers are moving up or down. If you attempt to engage the sostenuto pedal while the dampers are moving, you risk getting the leading edge of the damper rod (which is flattish, not round) jammed into the little tabs in the damper mechanisms that are meant for resting on the sostenuto rod when its engaged. For the tabs that get jammed or stuck this way, this stresses them and the damper mechanism as a whole. I wasn't trying to use both the sostenuto pedal and dampers at the same time, but every now and then my pedal movements would get out of sync and some tabs would get stuck against the leading edge of the sostenuto rod, hence the creaking sound. The solution was to refine my technique accordingly.