I am after some approx decibel rating for a racefit growler and also a few different slip on's. So i can kinda compare them to a Racefit growler on a 04 R6. I like the look of them but how everyone talks about them on here they are fair loud. I don't want something that is uncomfortable to ride with. If they are a loud slip on is there any way of moding them to quite them a bit like putting different packing in them/adding baffles?