TromboneChat

Hello!

For a couple of months I have been noticing problems in my high register when playing forte.

Eb, E, F and G of the second and third additional lines sound with good quality on piano or mezzoforte. But when I play them at f or ff the sound opens up too much and the notes crack. I've never had this problem before and it worries me a little.

I would like to know if it has happened to anyone else. What advice can you give me to correct this? Thank you for your attention

Can you post video? No way to say what's going on without being able to see and hear it.

As David said, there can be so many reasons, it will be impossible to give you an analysis without further details.
You might be able to rule out some obvious equipment-related issues:
- Have you changed anything equipment-wise lately? Of course a mouthpiece change can be causing issues like that
- Have you made sure there are no obvious issues with your equipment? I once had one of my kids' toys stuck in my bass trombone bell. And it took me a while to realize that this time the issue wasn't me. Also just cleaning the mouthpiece and/or slide CAN be a quick fix. But I would hope that is not the reason

Other than that - best is to have a lesson and/or someone look at what is happening with an educated outside perspective.

You need to share video, but...

From your description I suspect you're approaching those notes from below.

Does the same thing happen when you approach from above?

When I had a similar problem long ago, someone told me, "Put more lip in the mouthpiece." I think he meant that I was doing a smile technique or something. Anyway, it made me change my embouchure, and my range improved.