Double bass also refers to a large
drum kit (sometimes called a trap kit by us
old-timers) that has two bass drums. Each has its own
bass drum pedal, and the drummer switches one foot between the
hi-hat (or
sock) and one bass drum pedal as needed during a song. Using both feet, polished double bass players can accomplish hyper-fast combinations and rolls using their feet. One of the fastest double-bass players I've heard is the drummer for
Primus.
Some famous double-bass drummers include Neil Peart, Mike Portnoy, Lars Ulrich, Louis Bellson and 'Doc' De Marco.