With regards to the concern about wind.
Consider that the fan blades are pitched so as to oscillate back and forth at the playback frequencies. The blade pivots mechanisms are actually attached to a traditional voice coil mechanism so they oscillate just like a speaker cone.
The whole concept is to fit a *effectively* big cone, with a giant Xmax factor, into a small space. The room just thinks there is a giant woofer pushing and sucking, and that creates the change in pressure that we perceive as sound. But, it's all done with a tiny fan.
If there is no sound being sent to them the blades spin but they are "flat".
They make noise when they "push" or "pull" the air. It just happens that the pivoting movement creates a complex wave front rather than the constant drone we recognize as "fan noise" of a fixed blade fan.
So there is some very minor fanblade noise, but not what I think most people first anticipate.
If the fan is not making a specific sound with it's variable pitched blades... it spins with the blades flattened and the blades are relatively silent.
There is a very faint motor noise as well... but the motor is operating in another room.
With regards to concerns about Wavelength:
Distance, size, etc of hearing apparatus seems to help with localization of the source of a sound.
Our ears hear the Delta or Change in sound pressure levels. We can hear that
change in pressure easily with the ears we have.
I will speculate that some of the things Steve mentioned about ear structure are evidenced in the Flecther Munson curves and that our ear structure is related to the SPL required for our ability to perceive the presence of the sound.
I will speculate that this is why, as Drew mentioned... low frequencies need to be at higher SPL for us to listen to them along with easier to hear frequencies. It's how our ears work.
Hi Steve,
One of the things this new woofer has done has been to allow people to study and demonstrate that we can clearly hear down to a couple Hertz. Prior to this technological development there wasn't an effective way to produce an isolated test tone. Now there is. Come on over, we'll go on afield trip. :-)
Historically there were many researchers who knew we could hear down there... but now they are using this woofer to present better proof. Mr. Thigpen told us that, to date, most of his customers have been researchers who had a long standing desire for the ability to make test tones like this and so they have made purchases and integrated the tech into their ongoing endeavors.
All the best,
mike
post edited by mike_mccue - 2013/04/24 08:16:54