Is kind of funny.
When we making fan never think about sound. We thinking about how to get the best performance. How to fly big model on least amount of power. Electric always had been short flight time or over amps the system and hard on equipment shorting the live time on the fan system.
Our goal had accomplish. We had flew from the smallest aircraft up to the biggest BVM Mig-15, Skymast F-86, BVM Bandit and the lists can goes on. You guys get the idea. If you do the search on all this aircraft. Which fan is flying it?
The only negative comment they can said about TJ100 is sound......but not even one of those nice sound fan can fly any of this model with decent 4-6 minutes flight time on less expensive batteries pack like our fan are using.
Fan is about effecient. Yes, sound would be nice.
That what we do next. By offer 7 blade stators for twin projects to change frequency of the sound. But not give up the performance.
I'm sorry for those doen't like the sound. There is many fan with nice sound out there. You can buy one and go do the project you like.
Show us videos that you had good success. I like see them or other like to see them and decided what to buy.

Here is the F-18 video.
This aircraft weight 25 lbs.
It only use 3.4kw per fan and it was very effecient. This is stock 5 blade stator. The 7 blade stator sound even much quiet.
http://www.youtube.com/watch?v=6ADRuViwohw

If you look some part of the video with about 1/2 throttle.
That what is sound like in the A-10 using that low power set up.


BVM Bandit
http://www.youtube.com/watch?v=dqzNqVJ2SzY

CARF's Hawk
http://www.youtube.com/watch?v=bLB9_BsbrPE

BVM Mig-15
http://www.rcuvideos.com/video/Mig-1...J100-video-wmv

Skymaster F-86
http://www.youtube.com/watch?v=6xNz9-EiBA8