Technology / Home Audio / Headroom: A term related to the dynamic range of amplifiers, used to express in db, the level between the typical operating level and the maximum output level (onset of clipping). For example, a nominal +5 dbu system that clips at +25 dbu has 20 db of headroom. Because the term depicts a pure ratio, there are no units or reference-level associated with headroom, only relative 'db.' Therefore headroom expressed in db accurately refers to both voltage and power. Which means the example above has both 20 db of voltage headroom, and 20 db of power headroom.