Jo, how long was your 44 on before it mellowed out a bit? Is this something that happens pretty quickly or is this a several month long thing? Is it just due to carbon build up on the inside of the muffler or something like that? I'm not really familiar with how muffler work in detail. I just know a bit about rapid expansion and compression of the gasses. I've noticed that after just a week the glass pack has mellowed out some....I still detest the sound of the glasspack though. Acceleration also seems to have been reduced over stock