I have them on my Type S and the only noticeable noise change was a "rushing of air" ypet sound coming from the headers and also a slightly louder growl sound at lower revs. I have a Fujitsubo Powergetter which are know NOT to be raspy or drone too much so I think this helps with problems like you are talking about, I'd recommend one of these if you can get your hands on one but it sounds like you have already bought a new exhaust.