Jo-Ral B5 Bass Trombone Wah-Wah Mute B5 Bass Trombone Wah-Wah Mute The Jo-Ral B5 Bass Trombone Wa-Wah Mute creates the most exciting tonal quality, resulting in near-perfect intonation They are made of spun aluminum, and have been tested to perform evenly in all registers With its unique acoustical design, this mute sets the standard for wah-wah type mutes Its distinctive shape conforms to the contours of the bass trombone bell to provide a powerful muted sound when needed