While it’s difficult to explain these different sounds in words, “broad” sounds like shining a flashlight of sound out of the instrument-wide, open, but perhaps cloudy. “Focused” is more like a laser beam of sound-narrow, quick, and powerful.

The change from “warm” to “brilliant” might be best illustrated by singing the vowel “Oooh” and changing to “Eeeh” (without changing pitch). “Warm” cello strings are also described as deep, dark, but sometimes muddy. “Brilliant” cello strings are also described as clean, crisp, but sometimes shrill.