I've been learning a trombone for a few months now and recently I started having an issue that after some time of playing my low Bb alternates quickly between pedal notes and Bb and then it just plays pedal notes. I play mostly with yamaha silent brass so Im wondering if that might be the problem

I have not seen that before, but I wouldn't judge anything based on using a silent brass.

Given that it seems to happen after a certain time i thought that my muscles get tired due to increased resistivity of the mute also worth montioning that I only have this problem in 1st position when i play other ones in that partial or try to gliss from that pedal note its back to normal

[quote="Doug Elliott"]I have not seen that before, but I wouldn't judge anything based on using a silent brass.[/quote]

Do you remember me complaining about a double buzz on the low Bb where it would split to the pedal? I can’t recall that you ever saw it or not, but I do remember your advice at the time was to make sure I wasn’t overdoing my embouchure motion to descend, as I was also reversing that between low Bb and pedal Bb. Your thought, if I recall, was that I was too far in the descending direction by low Bb.

[quote="Gedlik"]I've been learning a trombone for a few months now and recently I started having an issue that after some time of playing my low Bb alternates quickly between pedal notes and Bb and then it just plays pedal notes. I play mostly with yamaha silent brass so Im wondering if that might be the problem[/quote]

I would need to see and hear it. It could be similar to what I went through. Can you post video?

Dave