my question is where do you get this information(knowing ones stuff) is this knowledge from luthiers handing it down from generation to generation. Is it from records that can be read? Are there books on the history of double bass commerce with empirical data that was gathered and recorded. Is this knowledge(knowing stuff) learned devotionally, ie. grandpa said so therefore, that's the way it is. I am not trying to be flipent here, I would really like to know if there are valid, unbiased history written objectively that covers this stuff. Please don't tell me that you learned it from bassists and luthiers a talkin and guessin. Again, I am not trying to be anything but curious here. In other words, how do you know this info to be facts. Where or from whom did you learn it?