This (and also the second part) is by far one of the best books on the topic. It explains musical and mathematical concepts in a very clear language.
You have to have of course some knowledge of mathematics but you should be able to understand everything if you know a little bit about trigonometry, algebra and complex numbers. No need for differential equations or higher mathematics.
I love this book for not messing around. Using mathematics allows Loy to formulate music theory and acoustics in a very concise way. As a student of mathematics I can't judge the difficulty, but it should be understandable for almost everybody (lots fractions, solving simple equations and a bit of differentiation is almost all that's needed). The range of topics covered in the two books together is breath taking. I'm currently half way through the first book and read it whenever I have a free minute, it's a great read!
Das Buch gibt einen guten Überblick über alles, was mit Mathematik, Musik und Schallausbreitung zu tun hat. Liest sich gut und ist selbst für jemanden wie mich, die auch beruflich mit dem Thema Akustik zu tun hat, noch interessant.