Hello all. My understanding for backcheck influence on sound is so : when the hammer comes back into check, the quality of the shock is very different if checking is high than if it is low : on high checking the hammer tail comes closer to vertically hit the top of the backcheck, making a kind of "hard landing" (to use André's words; say, André, do you keep the terms hard landing for after touch regulation, or do you use them in this meaning also ?) that is close in time to the hammer-sting contact. When checking is very low, the checking occurs of course later, and with a more close to horizontal movement pushing smoothly on the backcheck wire, and making a "soft landing". This shock is transmitted to the case by means of the key. So, exacly like the different quality of shock caused by key stroke on harder or softer front punchings, harder or softer landing of the hammer into check will influence both sound and touch, by mixing it's own energy back into the soundboard, and bridge, and back into the strings again. One thing is clear to me, the touch feel percieved at the finger has an analogous effect on simultaneously percieved sound. So, even a slight "objective" difference in sound can lead to a huge "subjective" perception of that difference in sound, by the player at least. If this all is acceptable, though, there is one thing that I don't understand clearly. Why is a hard landing at front punchings percieved as better than a softer one, while at checking it is opposite ? To be honnest, I have tried harder front punchings and softer ones on the same piano (Steinway A) and I keep swinging from one to the other : I find that the sound with harder ones can be a bit disturbing in the trebble area when you play loud and fast (makes kind of tac tac tac tac tac sound that could become ennoying), but if feels so good to have the finger know exactly where the bottom is. Now, the combination of hard front punch landing and hard hammer check landing kind of spoils the good touch feel. But I am quit e sure that with other hammers, other tone balance, the picture can get other colours. Just my (unauthorized) thoughts, hoping they are not impertinent. Stéphane Collin. ----- Original Message ----- From: "Isaac OLEG" <oleg-i@noos.fr> To: "Pianotech" <pianotech@ptg.org> Sent: Sunday, August 15, 2004 11:11 PM Subject: RE: punching, it hits you - backchek height > Hi Richard, > > Without a very logic explanation myself at this moment, the backchecks > height change the synchronism hammer check/key bottom. All this act at > the same moment the tone begin to be produced, so it seem "normal" > that an influence exist. > > But I am yet to find a good explanation ! > > Checking height, also, gives more or less strength on the repeated > notes, may be only because lower checking oblige the pianist to play > with more force/articulation. > > That is funny as any setup that oblige you to play stronger gives also > an impression that the tone is stronger , for instance the infamous > repetition springs added on the jacks on vertical pianos, that slow > the finger and oblige you to produce a strong attack. > > Best Regards and a good week . > > Isaac > > P.S I like when I ask very special questions to someone and he answer > "' yes of course" almost like if it is a stupid question. I had the > same to some techs about if the install the Steinway iron plate under > tension, and they look at me like if I was crazy to ask ! > > > > -----Message d'origine----- > De : pianotech-bounces@ptg.org [mailto:pianotech-bounces@ptg.org]De la > part de Richard Brekne > Envoyé : dimanche 15 août 2004 22:27 > À : ilvey@sbcglobal.net; Pianotech > Objet : Re: punching, it hits you > > > David Ilvedson wrote: > > >I have heard of washing and drying punchings to change density and > mainly stability... > > > >David I. > > > > > > > > > Well, I have to admit that a few years back (4-5) this concept was new > to me as well. Andre started talking about it, and then we who know > him > here of course started giving it a try. First for me was simply > noticing the difference between pianos, and trying to experiment a bit > with trying out different things. I remember a Petrof grand that I > ordered some very hard punchings for through the Steinway rep here. > (course I told him is was for a Steinway :) ) I was really suprised > at > the difference, but then Petrofs are (were) known for very soft action > felts almost as if they wanted a lot of give in the action. In > anycase > the difference was obvious, and everyone who plays on this agreed that > the difference was for the better. And interestingly enough many > students remarked that they thought the tone of the instrument had > improved. > > This brings me to another one of Andre's suggestions... that about the > height of the backcheck having an impact on tone. Now this one is > just > plain weird sounding... I'll be the first to admit it... but there it > was. When Andre was up here a couple years back he demonstrated it to > 5 > of us, and no one could avoid admiting that he'd changed the tone... > the > openess of the tone on the notes he'd adjusted. I asked the famous > Japanese pianotechs Mr. Ono and Mr. Takahara about this too whilst I > was in Japan this summer, and they both immediatly responded along the > lines... "but of course-- didnt you know that ???"... tho to this day > I > have yet to find a satisfactory explaination for why the height of the > backcheck can influence the openess of the tone of the piano. > > Anyways... I've come to learn, as Isaac has as well... that Andre' is > full of a lot of piano tone knowledge. Much of it based on hands on > experience as opposed to engineering expertise. Funny how that still > in > these days almost always yeilds the best advice. > > In anycase... like I said... I suggest you start experimenting around > with punchings densities just to see for yourself. Another felt I've > been thinking of trying to replace with some of this Wurzen stuff is > the > whippen cushion. I'll have to wait tho until the appropriate felt is > available from Wurzen... and I have this Petrof in mind once again. > > Cheers > RicB > > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives > > > > _______________________________________________ > pianotech list info: https://www.moypiano.com/resources/#archives >
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