PWK was clearly a man that stood on the shoulders of giants. The bulk of the Klipschorn’s design was executed in his spare time during WWII, while working 80-90 hours a week for Uncle Sam! Early in his military service at the Southwestern Proving Grounds, Paul acquired this book, along with many others specific to his then hobby, loudspeaker design. As with many of his books and scientific journals, he left his mark with “notes in the margins”. Mr. Bruce Marlin donated this book, which was given to him by Paul during his own engineering service to Klipsch & Associates in the 1990’s. We are deeply indebted to Bruce for this significant addition to the PWK Library. We are just now “bringing out of the closet” this massive library collection at our additional facility located at the Hope airport. If there are other PWK-owned texts or journals that you may have, KHMA would be most interested in acquiring them, or at least getting the opportunity to scan them for the Archives. Thanks Bruce!