Interesting article over at the OPen Culture website on an Octobass, a triple bass instrument built in 1850 by French maker Jean-Baptiste Vuillaume of which only three were made. This monster string bass goes all the way down to 16Hz. If you're looking for growl, this monster delivers.
Check out the rest of the article (with videos) here.
Check out the rest of the article (with videos) here.