Originally posted by jultzya
Forget the filter.
You can't start changing blower speeds until someone can verify whether it is wrong or not.
Have the HVAC Company out to inspect the system and to find out WHY it is noisy.
It could be the blower, it could be the ductwork. But one thing is a fact, we can't see it, and you don't possess the equipment needed to perform the required testing to determine the actual problem.
Another fact is, if you start messing with the system yourself you could create other problems that could lead you down the path of an EXPENSIVE repair.
I know that is the last thing you want, so that is the reason I'm heading you towards your HVAC Company. ;)