Hi all Greg says : Um, compression ridges are clearly broken fibers are they not? I think we all, or nearly all are in agreement that compression ridges show an area of the soundboard that has been over stressed. A thin line as it were representing a fraction of a precent of the area of the soundboard... and as such as significant in itself to the sound producing capabilities as your usual tension crack. They DO show clearly that the soundboard is under quite a bit of compression in general... I dont think however one can say that the appearance of a compression ridge or two defines a board that is on the whole destroyed by compression. Especially when they remain in ridge form for year after year and do not eventually yield a crack. I have an example of an 35 year old Petrof with 3-4 ridges that is quite lively indeed. This despite many many hours of use in a university setting. No cracks... plenty of sustain... tho admittedly it no doubt had more life at some point. Still its a very nice sounding instrument. Newly rebuilt action ... the thing was picked out by one of the professors here for his primary instruction instrument. And he could have had a brand new Yamaha C-6 from the showroom of the local dealer. Cheers RicB
This PTG archive page provided courtesy of Moy Piano Service, LLC