[DannoXYZ]

Originally Posted by Mohawk

What we perceive as noise is actually sound pressure. If you can modify the apparent sound by tuning the harmonics then you get an apparently lesser or greater sound.

Straight through performance exhaust create a distinct sound wave, the baffle changes the tone, by both volume & area reduction this is usually enough to reduce it enough to defeat he dab meter, but not reduce performance to much, they can help in certain parts of the rev range netting you a little more torque.

YMMV

thanks for info! So you're saying it changes frequencies of helmholz resonance? A little more restriction and slower flow can certainly move torque-peak around. More would certainly beef up mid-range. Kinda like what Kawi did in going from pregen to newgen.