Editing Sousaphone (section)

===Additional valves===
In the 1920s and 1930s, four-valved sousaphones were often used by professional players, especially E{{flat}} sousaphones; today, however, four-valved B{{flat}} sousaphones are uncommon and are prized by collectors, especially those made by Conn, King (H.{{nbsp}}N. White), and Holton. [[Jupiter Band Instruments|Jupiter Company]] started production of four-valve BB{{flat}} sousaphones in the late 2000s, and [[Dynasty USA]] makes a four-valve BB{{flat}} sousaphone as well. Criticisms of the fourth valve on a sousaphone center on additional weight, although the fourth valve improves intonation and facilitates playing of the lower register.

Due to the large size of most sousaphones, the sub-contra register (for which the fourth valve is largely intended) is already covered by alternate resonances, known as "false tones" (see [[Tuba]] article). Many beginners are not aware of the false-tone resonances on their sousaphones because these notes reside in the sub-contra register, which is nearly impossible for most beginners to access. Some professionals develop a "raised embouchure" to securely play these notes. This is where either the upper or lower lip (depending on the player) takes up most of the mouthpiece area. The embouchure provides almost twice the room for vibration of the single lip (compared to the 50–50 embouchure).