Boom mics can be either condenser or dynamic microphones. The type of microphone used in a boom setup depends on the specific audio needs of the production and the personal preferences of the sound engineer or operator. Condenser mics are more sensitive and can capture a wider frequency range, making them ideal for capturing subtle nuances in sound. Dynamic microphones, on the other hand, are more rugged and less sensitive to loud noises, making them ideal for capturing dialogue in noisy environments.