I am upgrading my dust collection piping to 6”. Since it is just me, only one machine at a time will be running. From the 6” branch line, I will be putting drops to various machines, terminating in a 4” flexible hose. The question is, do I continue the 6” down to the 4” flexible hose or do I reduce down to 4” at the top of the drop, right off the 6” branch? I would first use 4“ piping on the drop until the 4” flexible hose. Or should I first reduce to 5” at the start of the drop terminating with the 4” flexible hose? I have a 32 year old 2 hp dc with 12.75” impeller.