Well it may well be apples and oranges. Part of the reason for my inquiry is that I'm giving a presentation soon on choosing replacement hammers. Of course there are many criteria and considerations but one, of course, is weight. Let's take Steinway for example, not to pick on them but because it's a good illustration. The original hammer on a Steinway from the 1920's was very light in weight. In my view it suited that scale and belly fairly well. It's not unusual for the hammer at note 40 to be on the order of 6.5 grams. When looking at hammers offered for replacement on those pianos (even by Steinway themselves), it's not unusual to see the them increasing in weight by several grams. Those who have made the mistake of doing so without modifying the leverage know the disastrous results in terms of touchweight. So, it's not unusual to change that original 15.5 or 16 mm knuckle to a 17 mm knuckle to accommodate. But how many people, I wonder, consider what the increased hammer weight does to the tone when they opt for that new hammer. Judging from what I see, not many, unless people are opting to increase weight for a specific tonal reason, i.e. to get more power, attack etc.. Even the sticklers for "original Steinway parts" must admit that the new hammer (and even more so the bulkier hammers that were offered from the 1960's through the 1990's) were substantially heavier, produced a very different tonal attack and development, and increased power. Now on an old Steinway board that might be ok but it might not, depending on the condition of the board and other factors. Certainly it changes the tonal character. So as a not too random sampling I'm interested to know how many people do or don't consider weight of a new hammer in terms of the change in tone that it will produce. Or do you just select the favorite hammer of the day and adjust the leverage accordingly (hopefully), assuming voicing will take care of any unwanted changes? Further, does the original hammer that Steinway produced for that piano (keeping in mind that the piano of that era produced and maintained a somewhat stiffer board than the one after they began to diaphragmize) suggest that they were focusing on power in their original concept? David Love www.davidlovepianos.com -----Original Message----- From: pianotech-bounces at ptg.org [mailto:pianotech-bounces at ptg.org] On Behalf Of Mike Spalding Sent: Wednesday, March 24, 2010 11:32 AM To: pianotech at ptg.org Subject: Re: [pianotech] Force equivalents in different actions Some additional thoughts: 1. Producing identical sound loudness probably requires equal energy transfer from the hammer to the string. Energy is not equivalent to momentum. Energy is mass times the square of the velocity. 2. To ask the question the way it has been phrased, assumes that the motion of the key is the same in both A and B. I think this is unlikely, as the inertia seen by the finger at keystick B is significantly less than in A, so the same pianist will produce different velocity profiles in the two keys. 3. A slower heavier hammer transferring the same amount of energy to the string will probably have a different dwell time at the string. Will that affect how much of the hammer's kinetic energy actually gets transferred to the string? Not a simple answer, since we're talking about energy distributed across a spectrum of partials. Perhaps you could equalize dwell time through voicing. Perhaps you'd rather make them sound as similar to each other as possible through voicing. In either case, it's starting to look a lot like apples and oranges. Mike
This PTG archive page provided courtesy of Moy Piano Service, LLC