This is my first post here on SOTW. I am relatively new to the saxophone, I play a King straight soprano. I am getting a vibrato type gurgling sound when I play in the lower registers particulary low D or C. I have taken the horn in to a reputable technician that my teacher also uses. He replaced some worn pads and reset the stack however I still get the same sound. He said that the older horns have this problem, mine is a 1926, he did not get the sound when he played it and it sounded beautiful but said that he naturally was adjusting for it, he did not charge me because the sound was still there for me. I use an Otto Link #5 metal mouthpiece and a Vandoren Java 2.5, the tech was using a selmer. Could the mouth piece be the problem or is it the horn or is it me and my lack of experience, embouchure etc.? He let me play another soprano that he had just finnished working on with my mouthpiece and it sounded beautiful from top to bottom with my otto link. Any help ot advice or comments would be greatly appreciated.