[HayZee518]

I'm afraid so. If you go into a store someplace with an open grid of piping for an overhead sprinkler system look carefully at the piping. what you'll see coming off the standpipe is a rather large pipe, say 4 inch running the length of the line you'll also see that the pipe diameter reduces every so many feet and still has 1/2" or 3/4" sprinkler heads on it. The very tail end of the line the diameter has reduced to about a 1 inch line with a sprinkler at the very end. Same mainifold reduction size should exist in your home. with a 1/2 inch copper pipe you can have say 60 lbs of pressure and with a 3 inch pipe you can also have 60 lbs of pressure but open one end, the volume decreases so will the pressure. your fixtures use 3/8 inch flex copper or brass tubing, so the pressure is once again decreased.