let go vs let loose

let go and let loose both are verbs.

Word	Noun	Adjective	Verb	Adverb
let go	No	No	Yes	No
let loose	No	No	Yes	No

As verbs, let loose is a hyponym of let go; that is, let loose is a word with a more specific, narrower meaning than let go:

let go (verb)	let loose (verb)
release, as from one's grip	express audibly; utter sounds (not necessarily words)
be relaxed	turn loose or free from restraint