Click here to purchase the entire book in PDF format. Geometry It may initially seem that a section explaining geometry is a very strange place to start a book on sound recording, but as we'll see later, it's actually the best place to start. In order to understand many of the concepts in the chapters on acoustics, electronics, digital signal processing and electroacoustics, you'll need to have a very firm and intuitive grasp of a couple of simple geometrical concepts. In particular, these two concepts are the right triangle and the idea of slope.