The purpose of the book is to tell in a popular form about the construction of loudspeakers in amateur conditions. The approach to choosing dynamic heads, the theory of construction and the methodology for designing crossovers based on computer technology are simply and clearly presented. The presentation of the theory and methodology for crossovers is based on graphic material obtained as a result of measurements and processing the characteristics of real dynamic heads. The application of the technique is illustrated by examples of designing two-lane and three-lane crossovers. The book is designed for a wide range of sound reproduction technique lovers.