In an orchestra, what is the lowest member of the brass family?

The Tuba is considered the lowest member of the brass family in an orchestra due to its ability to produce the lowest notes. It is a large, deep-bodied instrument with a wide conical bore that allows it to create deep and rich tones. The Tuba adds depth and foundation to the brass section, providing a bass line that supports the harmonies and melodies of the ensemble. Its lower range makes it unique among the brass instruments and allows it to create a booming, resonant sound that is essential for orchestral compositions.