Will aftermarket exhaust sound change over time?

Hi,

I just got V&H Twin Slash installed on my M800. I got it with the quiet baffles in it right from the start. Well the sound is impressive and with the quiet baffles it not quiet at all but has a deep tone. The smile on my face was really wide already on the way home though it was only 8 degrees:)
In the workshop they mentioned that the wrapping of the fiberglass will burn out but will it change the sound? I mean a kind of "break in" period. Let's say after few hundred kilometers will there be some kind layer of grime or smut on the inner surface of the pipe that would alter the sound to be even less high-pinched?

What have you experienced?

They should have slightly less of a metallic sound after a layer of carbon has built up inside, won't be much though. 

ps. I was unaware "slash cuts" had fiberglass on the baffles? mine didn't.

Not on the original baffles that comes with the pipe but the quiet baffle has some kind of wrapping.

Reduce of the metallic sound is exaclty what I expect:)

Maybe the metallic sound is enhanced by the quiet baffles. Try taking them out.I had shorties on my Intruder. They were quite metallic sounding with the baffles in and deeper with them out (but loud!)