The design and shape of a prop play a role in the amount of noise they make, beleive it or not, most of the noise you'll hear from your model (if you've got a muffler on it) is the prop. APC props tend to be the least noisy, and the most efficient, unfortunately more breakable than Master Airscrew. I agree that Master Airscrews are the best prop for you to learn as they'll tolerate the occasional turf slap of the beginner landing that would make throwing Knives out of an APC. Good choice on the 11x5 too.

JJ