Scientifically speaking, there are two major problems with a test like the one described in Mark Cramer's post. 1. There is no way to make a direct comparison of "before and after". It depends upon tonal memory, which in humans does vary from time to time, time of day, how well one slept the night before, what one had for breakfast or lunch, to drink, etc. 2. It is impossible to rule out factors other than the one being tested - the WAPIN in this case. When one tears a piano down and re-strings it, one has already done much more than just installing the WAPIN. Whether or not the WAPIN made a significant improvement is masked by the fact that other things were done at the same time. Someone suggested making before and after recondings. This is a good idea, but it has it's own set of problems. I have done lots of piano recordings and spectrum analyses (3-D as well as narrow-band), and I speak from experience. There are plenty of quality recording devices available. That's not the problem. It's first shortcoming of before and after recordings is that they only address problem (1) above - tonal memory. It's second shortcoming is that the before and after must be done under identical conditions, and I do mean IDENTICAL IN EVERY WAY, which is sometimes hard to do. The placement of the microphones is very important. The slightest difference in the before and after placement will throw in all sorts of false results. Any changes in the environment - the exact position of the piano - where a person is sitting or standing - where objects are in the room - will all have an effect. In the case of the WAPIN, there is a simple way to avoid all of the above problems. Install it in every other unison, and install normal bridge pins in the alternate unisons. The entire bridge installation would need to be new. That way, "the playing field would be leveled", so to speak, and one could make direct comparisons, note for note, all up and down the scale. That would be a true test, and it would rule out time-related personal impressions that may not be reliable, pro or con. Sincerelly, Jim Ellis
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