I got a new Claude Lakey jazz mouthpiece about a month ago and lately it sounds like it is leaking. When I blow I can hear air...like it`s leaking from the mouthpiece or something. Is this something I can fix or is it the mouthpiece?

THANKS!

is it a rubber or metal mpc?

It could be your embochure? While playing, when you hear the air rush lift one of your hands and feel around the mpc. Could be your emb. Could be the flat part of the mpc isn`t flat - check it on a plate of glass.

Is the tip opening the same you have used before, thus same or different strength reeds??

maybe the cork is breaking apart and you are getting an air leak there.

Or, if you play tenor, you could be hearing nose from the neck octave mechanism more readily with that mpc ??