No, the French sentence is fine. The problem is that both the "passé composé" and the "imparfait" verb tenses can be mapped to the Simple Past tense in English.
IMHO "You were speaking too loudly into the mic" would be a more accurate translation and would prevent the ambiguity of the current translation which uses the Simple Past.
It's imparfait and not passé composé. Imparfait is generally constructed by adding the base root of the verb (parl-) and adding the imparfait ending:
- -ais (for 1st person singular i.e. "je")
- -ais (2nd person singular i.e. tu)
- -ait (3rd person singular i.e. il/elle/on)
- -ions (1st person plural i.e. nous)
- -iez (2nd person plural i.e. vous)
- -aient (3rd person plural i.e. ils/elles)