I suppose if you get a mandrel bent exhaust system, high flow cat and two hi flow mufflers with all the right sound deadening material, then it should be fairly quiet (Compariatively, it'll be louder than a stock, as it's breathing more, but quieter than a straight through with only one muffler on it)
There is a certain amount of the set up affecting the note that comes from the end of it, and how loud it really is. I've seen a few cars lately that have extremely LOUD exhausts, and even louder sound systems (That... And they drive around with all the windows open, making the car louder to them, so they put the music up more! I have my window open when driving because I can't afford a regas at the moment, sheesh)