From Christian Greigo:
Orchestral players who play a 59 or 1¼ will love the feel of the Griego 1. Most bass trombone mouthpieces are unbalanced, which causes a wide array of sound widths and tonal colors throughout the different registers. We have paid very close attention to the balance between the cup, throat, and backbore of our mouthpieces. The end result is a mouthpiece that maintains tonal color no matter the tessitura. The upper register maintains the core sound without becoming diffuse. The lower register is full with plenty of energy in the sound.