Some need for explanation ... Optimal settings and the volume issue

Video at Amazon.com See 8 (I was a free sample for review provided the full review with the long video and lots of pictures you will find on my blog -. Just search for "Zero Brain LED 66" search).
TECHNICAL SPECIFICATIONS

(Measured):
Minimum distance (measured): approx 2.20 m
Image Size attended: about 1.4 m
Power consumption: ca. 109 Watt
Standby: <2 Watt

(According to the data):
Resolution: 854x540 pixels
Contrast: 800: 1
LED life: 20,000 hours

What I liked:

-Optical Keystone Correction (Keystone)
LED light source (no heating / cooling period)
-cheap price
-HDMI Input
Remote control (but: too much buttons)
-Good Accessible air filter
-USB Connection
-What I did not like:

Sound
-Resolution Not FullHD
-Netzkabel Too short
Speaker only "tolerable" (especially too low)

Conclusion: You get now an astonishing amount for your money. The not "Full HD" resolution, I could get over, the volume of the fan not.

What has the fan noise level WITH THE ZOOM LENS TO DO?

Nothing much and at the same time. A lens, such as the built here, allowed at a certain distance exactly one (!) Image size. Larger Image means further move away the projector from the screen. And so the noise source moves often towards the viewer.
For fan volume we read many opinions that speak of "Turbine". That's an exaggeration. As shown in the video, I found the sound in "my" room volume of the test film, however, to be very disturbing. Especially the second fan (later in the teardown images) which cools the panel, ensures that annoying background noise.

USB CONNECTION

Gladly I ignored because often implemented only neglected. My test film was shown but easily. Although the manual pretty ausschweigt how USB works, if you want to play movies:
Who wants to try it: choose as the source "Media", navigate with the arrow keys, press "Enter" to confirm the selection (the film is in the small window going) and then (I have by trial and error determines) the Play button (right arrow) press to switch to full-screen mode.