I noticed som warbling on my sax recently especially when hitting low notes up to mid C but only occasionally. I tried the crook from my other sax and that worked fine on my main sax so the fault is with the crane. I changed to cork today but the problem didn't go away. The only other shing i can think of is the octave key. Perhaps air is escaping from the pad. It looked too far pressed in so i wonder if the seal wasn't there. I lifted it out slightly and the problem seems to be alleviated but i suspect it might come back. Should i replace the pad or is there another solution?