Question about braces

[Ken McKay]

The papers I have read on vibration patterns of basses are on assembled instruments using lasers. This is a bit different from the free plate patterns which show the area of vibration of the plate only.

I think you are absolutely correct Eric, and Matthew. Bending the plate pretty much stiffens it enough to make it rigid so it only vibrates at higher frequencies in the area of the back above the break angle cross bar.

I think the major important factor of understanding this whole back stiffness concept is in the way it effects the bass response to bowing.

edit, thanks for putting that up Matthew, I am a big fan of Andrew Browns thesis work. I really think using the knowledge learned from his work has resulted in me making a better bass. In addition, I can't apologize for understanding the "technical" nature of the thesis. And it certainly doesn't imply that a maker has to understand what's in it to make a good sounding bass...obviously!