Looking for projection screen that's acoustically transparent, its tiny perforations allowing the sound to pass through unimpeded? Why not just get a screen that also functions as a speaker? The NXT Authentic ASS-60AK (Authentic ASS?!) Speaker Screen is made of Teonex, a special fabric that vibrates in such a way that it emits more sound than it absorbs.
Teonex is designed to work along with NXT's SoundVu technology, which causes the screen to vibrate, acting as a speaker. The company recommends using the screen as a center channel speaker in the place of an acoustically transparent screen. If this product ever becomes available in the United States, it'll cost you $520 to see if the ASS-60AK sounds better than its name implies.