If it is really loud then something is not quite right with it. Probably pulling too much air. You should be able to adjust the amount of air going into the ventrui.
Look at an Aqua-C Remora. They are very good skimmers. I wouldn't buy anything that has bio-balls or floss in it.
Got a used one for sale
During a break in period how do you set the skimmer? i have an adjustable skimmer, a coralife one i think but it has never worked quite right. Im wondering if it never really broke in.