Well, 2 and 3 are just confusing to me, so they are out.
(They make me think to much about the logo, is that really what you want for a BI - Brand Image?)
What is the "Mission" statement of AVS?
I tried to find one but could not.
A blog + forum site?
What is the purpose?
and truly how do you want to tie that into your BI?
The RGB gives a nice tech feel, and represents the video side by .... well simply "visually" .
Audio is missing from any visual representation, keeping the "S" in the logo keeps science - fact based data, as part of the core value of AVS.
Therefore I voted 1, but somehow would like audio to be part of the visual logo as well, w/o getting too busy.
(sound waves in the black mask possibly??
Strong on the lower left and fading into the upper right at they collide into the RGB??)
fwiw, the RGB immediately reminded me of this logo, don't know why http://www.curtpalme.com/
When I think of that site, video immediately comes to mind.