How can you do that?

scratch it with a screwdriver...

uh huh..
 

Thank you..

We used to test maple years back when it was hard to tell on some pieced if it was hard maple or soft maple as some of the Sugar maple looked soft. We used our fingernail. If it dented, it was soft regardless o f species. If not, it was hard.

I made this "wingless" bridge following some bassists' trend in Brighton,UK. It makes the sound brighter and gives a better arco response. This bridge has considerally improved the sound of the bass.
The top's wood is rather soft, since it is easy to make a dent with a fingernail.
I am in the middle of a serious engineering project so i haven't much time to take the top out. When i'll do it, i'll try to estimate the stiffness of the top plate using my knowledge from violins lutherie. I'll keep you informed. Thanks for all your input.