Red Bronze is a heavier alloy compared to brass. It's an alloy that consists of 85% Copper, the balance mostly Zin and Tin. The copper is the primary focus here as it adds more mass to the alloy. Red Bronze gives the saxophone a very unique tone, a warm, focused and classic sound which can be easily modulated. 

The use of red bronze gives the saxophone a richer and lush tone, due to the "damping capacity" and internal friction of the metal.