Post date: Oct 17, 2015 7:42:39 AM
I have done this many times, but it still surprises me how accurate it is. I new that the true M5 of the back plate was around 345-350 Hz, because of minor edge distortion. There is good margin to take it down once I have the top plate ready and know what I want to do. (download file below: Coupling_Soil2015_294Hz.mp3). 294Hz/329Hz(the other mode). Track these modes by holding it with your thumb at upper and lower end blocks and knocking in the middle of opposite lower and upper bout.Â