Let's remember, this lack of volume on the lowest notes of the tenor bridge occurs only on certain pianos, not all pianos. And.... we routinely correct this problem by just rescaling, achieving superb results. Clearly, barring some mechanical hindrance of the of the string's vibration, poor scale design should be considered as the primary cause. We shouldn't ignore this fact when we attempt to fix the problem. These other very interesting and intriguing effects, in THIS application, should be recognized as secondary cures. Before we technicians start drilling holes in back posts and screwing screws against ribs, before we start hanging weights to the back sides of our customer's bridges, I'd like to point out that this approach, in this situation, is curing the pain but not taking out the splinter. My comments regarding their effects were observations of their opposite influence on the bridge. One increased down bearing, the other decreased it. Yet both were being claimed to have the same effect, which is what I was seeking to understand. That's the mystery I was trying to grapple with. What was their commonality? What happens when you place a vibrating tuning fork on wooden surface such as a soundboard? I liken both 1) adding a screw against the back side of the soundboard from the back post and 2) the placing of a weight on the back side of the bridge, as the same phenomena. They are contact phenomena of transferred energy in both situations. David Sanderson Pianobiz@aol.com
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