Ziggy From United States of America, joined Jun 2001, 178 posts, RR: 0 Reply 1, posted (11 years 10 months 2 weeks 2 days 13 hours ago) and read 660 times:
From my understanding of Turboprops is their are two basic designs. One, being where the prop is connected directly to its own independent turbine. And two, where the prop is connected to the camshaft through a reduction gear box. One of these is louder than the other, but which one I don't know. Look up pratt-whitney.com, Look at the PW100 and the PT6A-large for more details.