Most tubists struggle with double tonguing (too heavy, too slow). Isolate the tu-ku patterns from the Arban PDF. Practice them on a single pitch (like low F) before adding scales.
: The hallmark of the Arban method, teaching players how to execute rapid-fire passages using "tu-ku" or "tu-tu-ku" syllables. 3. The "Art of Phrasing"
: Since the original was for treble-clef brass, prominent tubists and editors (such as Dr. Jerry Young and Wesley Jacobs) transposed the exercises into bass clef and adjusted ranges to suit the CC, BBb, Eb, and F tubas.