Edwards bass trombones are available in 9?”, 10?, and 10?” bell flares in a variety of wall thicknesses: 20 (heaviest), 21, 22, and 23 (lightest) gauges. Many jazz bass trombonists prefer lighter weight bells while orchestral bass trombonists generally play the heavier bells. The heavier bells are not as flexible in timbre but provide a very stable sound foundation.
Bells are available in yellow brass (70% copper 30% zinc), rose brass (85% copper 15% zinc), and red brass (90% copper 10% zinc). Higher copper content bells generally are very dark in the soft volumes but become more brilliant in the louder volumes. Yellow brass bells are more consistent in timbre throughout all registers and dynamics.