mellower

He's got mellower as he's got older.

随着年龄的增长, 他变得更成熟了。

The Baritone is similar to the Euphonium in terms of shape, pitch and range, except that the larger bore of the Euphonium gives its lower notes a broader and mellower timbre.

上低音号及粗上低音号的音域相同，唯前者的吹口径较窄，音色较明亮；而后者音色则较阔及较圆滑。