How Loud Should the Imaam Recite when Leading the Taraaweeh salaah?

Q: Salaah-202: How loud should the Imaam recite when leading the taraaweeh salaah and other audible salaahs?

Answer: It is best for the Imaam to recite without strain in a voice that all the followers can easily hear. Pretentiously reciting in a manner that is not necessary is forbidden. Allaah says: Do not recite (the Qur'aan) loudly in your salaah, nor softly, but seek a path in between these (two extremes).
Commentators of the Qur'aan state that reciting in this modetate manner affects the heart whereas reciting loudly and pretentiously strains both the Imaam and the followers and hampers humility.

The Fuqahaa have stipulated two conditions for reciting loudly. The first is that there should be no undue strain on the reader (which is Makrooh) and the second is that it should not cause a disturbance to others. For example, if a person is asleep or doing some work and would be disturbed by your reciting loudly, it will be Makrooh to do so. A further condition is that the recitation should be as loud as is required for the number of people following him. For example, if there are three rows of followers, the Imaam's voice should reach the third row.

Faqeeh Abu Ja'far RAH. says that the Imaam may recite as loud as he wishes on condition that it is not too strenuous for him and he does not cause difficulty to others. The preferred opinion is that of other Fuqahaa who say that his voice should be as loud as is necessary for the number of people following him. This should however not be too strenuous for him either.

Fatawa Rahimiyyah vol.2