dynamic headroom vs headroom

dynamic headroom and headroom both are nouns.

Word	Noun	Adjective	Verb	Adverb
dynamic headroom	Yes	No	No	No
headroom	Yes	No	No	No

As nouns, dynamic headroom and headroom are synonyms defined as:

dynamic headroom and headroom: the capacity of a system to reproduce loud sounds without distortion

dynamic headroom (noun)	headroom (noun)
the capacity of a system to reproduce loud sounds without distortion	the capacity of a system to reproduce loud sounds without distortion
	vertical space available to allow easy passage under something