How can I make my 10 watt guitar amplifier louder?

When the Fender company invented the first widely-produced electric bass guitar in the early 1950s, they also developed a bass amplifier, the Fender Bassman amplifier. The Fender Bassman is a 50-watt tube amplifier with four 10" speakers. The Ampeg Bassamp Company, founded in 1949, also produced bass amplifiers that were widely used by electric bass guitarists in the 1950s and 1960s.