Fans in Rear Speaker Placement?

[ozosrt4]

First post so sorry if I'm in the wrong thread for this questions. I have a Sundown SA-12 in a ported box tuned for SQ (25Hz F3) with my old school (mint) JL XR 6.5's for front stage. No rear fill with amp rack mounted underneath rear deck and I have two 160mm ultra quiet PC case fans that I would like to mount where the 6x9 holes are. My question is that if anyone has experience with this? I would think the sound pressure would make the fans flutter at the very low end? By the way I can not wait to get the SMD DD-1 to tweak my system for a clean signal, great work SMD.