What is the speaker size?

Speaker size is the size of the speaker Horn, Horn speakers for a circle to its diameter, to represent, for example 16 cm; for non-round speaker Horn, to the maximum size Westley square to represent, for example 15 x 23 cm. This parameter is mainly for coaxial speakers. Speaker size natural is better, a large-caliber speakers in low-frequency component for better performance, lower transient distortion and better sound quality.