No it hasn't quieted much. It is choked down to the 3/4 return size but even when I run it at low speeds it has a whine to it is actually worse at low speeds. I may be to picky it isn't unbearable but louder than I had hoped. I do like it
So did your whining noise go away on your dc 12000 pump? Mine is quiet as can be until it gets so much back pressure then it starts whining also. Great pump unless you have too many pipe lifts in your return manifold? Going to modify mine with less lifts and elbowd etc.