WHY AN ACOUSTICALLY TRANSPARENT SCREEN  ?

In every cinema we see and hear an AT (Acoustically Transparent) screen at work. The seamless synchronising of image and sound is fundamental to the film art of suspension on disbelief.

All three front soundstage loudspeakers are installed directly behind the screen with the centre channel being positioned logically in the centre of the screen.

So the right question is not so much “why an A.T. Screen  ?”, but “how much do we lose in not using an A.T. screen  ?”. To this question the answer would be far more than you might imagine.

When a non-A.T.is being used the centre channel loudspeaker must be located either below or above the actual image. As we view the film we become aware that the origin of the sound is clearly different to that suggested by the image. As the screen size increases this error becomes even more obvious.

This mismatch between sound and image location is all we need to realise it is not an actor speaking, but a sound system located somewhere else.

The lip-sync problem

Whether or not you are aware of it, we can all read lips and do notice when sound and lip movement are not synchronised. This synchronisation is essential to overall intelligibility, and in its absence the centre channel is often raised to try to restore the balance.

This level increase, often as much as 6dB (that is, multiplying power by 4) has significant implications in speaker distortion and the perceived balance of the front soundstage.

Next time you go to Cinema notice how easy it is to accept sound and image as one  ? Now, ask yourself, do you wish to have a «  Home Cinema  » or a Cinema in your Home  ? Only an Acoustically Transparent screen can realise this wish.