The phone number is right (215-412-7700) but his name is Bill LeGall, not Bill Miller. Millersound (one word) is the name of his business (in honor of his grandfather).
Bill is one of the true geniuses in this business, an honest businessman, and a true gentleman. I have the double fortune of owning one of his own speakers (no longer made), as well as a pair of Vandersteen 4A modified by him that sounds out of this world. He can take ANY speaker and make it sound better than the original.
Good Luck.