For HT use, you are right - a perforated screen is preferrable, and it is indeed the very configuration of all dubbing stages. It solves the problem on having the three speakers at equal height, among other things. Ideally, such a screen should be motorized (or movable) so that it is out of the way of the speakers when listening to music however. All perforated screens attenuate the high frequencies to some degree (some are better in this regard), and the screen itself can act as an interfering boundry to the sound from the speakers. With a motorized screen and three identical front speakers, you would have an ideal setup for both cinema and multi-channel music.