I recently bought a new (and hopefully last) miter saw - the Bosch 12 inch slider. I have a 3HP cyclone DC with 6 inch pipes in my shop. I made a larger rubber shroud to replace the original and so far have only used the saw DC port connected to one of my shop vacs until I can get it permanently connected to the larger system.
I intend to branch off and connect a smaller (probably 2 1/2 inch line) to the saw port and a larger line to a shroud that I'll be making to cover the area near the bottom of the saw. My dilemma is the size of the line going to my home made shroud. I know that a full 6 inch line will give me more CFM and a 4 inch line will give me more velocity. I'm not sure which will work better in this application and am looking for advice/comments. Sorry if this topic has been covered before; I have read a lot of threads on miter saw dust collection already.