I guess with the neck extension you're playing a small chambered, high baffled mouthpiece. If that's the case, I'd take the extension off and switch to a larger chambered mouthpiece, with a bit less baffle... and a nice fat end cork.
Pay a tech to do it, don't try it yourself if you have to ask. - I wouldn't do it myself either.poserama said:I play a 8* rubber link, could I get any wider? and how can I remove an extension without damage?
A rubber Link should play fine on a 10M without an extension, but as that doesn't appear to be the case, perhaps you don't want to remove it. How far does it push in for proper tuning? Mark the spot and see if you would have anything left to hold the mouthpiece if you chopped off the extension. If nothing's left, keep the extension. Some horns are just off. Well, that or you're chomping down too hard on those hard reeds.poserama said:I play a 8* rubber link