In another discussion
entitled "Prop Noise Comparisons
" James Pistorino
asks about the prop size vs. noise factor. This got me curious about something else, to which the answer seems intuitive, but I was wondering if anyone had real-world confirmation of this...
For an RC plane/drone flying at a few hundred feet (let's say 200'), using a four-stroke 28cc engine (so as to quantify the data), is there a substantial noise difference (as measured from the ground) between the muffler port exhausting (all assuming horizontal flight) upward, toward the back, or downward?
Does anyone have any real-time experience with this, as opposed to hypothetical extrapolation based on intuitive SWAG
with some hyperbole thrown in to sound more credibile?