Hi Donlboy,
I would echo the comments already made here. Most AT screens cause various reflections and audio anomalies as well as visual degradation. If you still want to go with an AT screen, here's a link to some interesting tests done by Mix magazine. Only one of those tested was reasonably transparent in terms of audible degradation of frequency response:
http://mixguides.com/studiodesign/product_features/new-perforated-screens-0405/The dispersion of good speakers like Axiom really make the notion of optimal speaker placement in relation to the screen a non-issue.
Regards,
Alan
