BTW, I pick 30 because that's just below the low B. I need nothing below that.
Mic'ing an upright is a completely different thing than driving a low B on an electric through a bass amp. That's why I refuse to give any sound man a single line with both upright and electric when I double. And since most sound guys have no idea what to do with upright, anyway, it's almost imperative that I maintain some control over the low end as they usually push it to the point of losing all distinction between notes. It's all so dependent on the room, it's really helpful to have a variable HPF.
Electric, OTOH, is cake compared to upright.