Me..., I'm a tweeker. Case in point. I'm getting ready to install H92s to replace my H91s.
First thing to do was to clean them up. This includes first filing out rough spots and ridges at the flanges and along the interior.
In addition to various casting "bumps" the horns have a slight ridge along the inner edge at the exit if the bell. I can feel it when I run my finger around the lip. An emery board makes this nice and smooth. I equate this with "port matching" when building a high performance engine. Of course the horns are then repainted.
As previously noted in another post, the horns also received a coating of plastic/rubber along their outside to deaden ringing.
Does any of this have any audible effect??? Couldn't hoit!
So, what tweeks have you done during your builds and were they effective?