not really unless your getting to a really small width and its hard for the air to move through the port. is more about width to height ratio and port area, not just the width.
You most likely want to go no lower than 3 inches in diameter, (for cheap PVC ports) or you'll probably get port turbulence... For smaller ports go with Aero ports or round the port tube at both ends on the inside, that'll work sometimes.. depends on how hard you push the sub