My Bb(s) are very, very flat

[IBSmiester]

My Bb2 and Bb3 (using the side key or bis key) are very, very flat, not just a bit, 30 cents! My G's can be perfect, and the rest of the horn very close, but not those two. It's been like this for sometime, no matter what reed I use. I can lip it up, but 30 cents is a lot to lip up and it's not comfortable for playing. Any clues?

[tenormelodies]

I've had a simular issues with a new selmer. I got it regulated and now it plays just fine. FInd a GOOD tech and tell him what's going on.

[EZ]

Sounds like the G key is set a little low when open. How does it look relative to the rest of the upper stack? Ditto on finding a good tech. Yamahas generally have really good intonation.