Hello members of TromboneChat!

I am posting to ask if anyone could give suggestions or ideas on improving my focus and clarity, especially in the lower register. Whenevers I play in the second partial (whether on the straight horn or in the trigger) I always have trouble "slotting" the notes or finding the right place to play them. On every other partial the note seems to have a spot where it likes to lay the best, but I can never find that sweet spot in the second partial.

On top of that, whenever I attack a note in the low register (but especially that second partial) it comes out fuzzy, like my ratio of tone to air has been completely flipped compared to the other registers. At fortississimo and above the note comes out sort of solidly but anything below that and I feel like I have no control (or get an ugly sound, as per recordings).

If anyone has dealt with this or has experience/ideas that could help please let me know, I'm sure other people would benefit as well!

(If anyone asks, I play on a Yamaha 882GO with a Shires 5MD mouthpiece)

One thing that came as a kind of small revelation for me when I started to play bass trombone is to realize that the lower register also requires a firm embouchure, even if your aperture is bigger.

Try playing the notes in that register softly, and with air attacks only, it's easy to use too much air and tongue to get the whole ball rolling in that register, and that can hide a flabby enbouchure.

To work just the embouchure, try slow glisses with air attacks.

JTeaGarden gave some really nice advice just above.

What I can add is do some mouthpiece/rim buzzing in that register to ensure you’re creating an efficient and easy buzz. This will also make sure you have a solid embouchure formed in the lower register.

Slur down from tuning Bb to low Bb. Keep the face largely the same as you slur down.