Home Cinema Design - October 6th, 2008
Designing dedicated home cinema systems is not as simple as it seems. James Moir once told us, “Anything obvious in acoustics is usually wrong.”
We should be aware that the art of home cinema acoustical design is only partially based on theoretical considerations, and it requires considerable practical experience. On the other hand, mere experience without at least some insight into the physics of sound fields, and without certain knowledge of psychoacoustic facts is of little worth, or is even dangerous in that it may lead to unacceptable generalisations.
Usually the practical work of an acoustic consultant starts with drawings being presented to him. These show the details of the dedicated home cinema room which is at the planning stage or under construction, or even one which is already in existence and in full use. The home cinema designer must work out proposals for changes or measures which are aimed at improving the cinema room acoustics, keeping in mind that these may substantially modify the architect’s original ideas, and therefore have to be given very careful consideration.
In order to solve these tasks there is so far no generally accepted procedure which would lead with absolute certainty to a good result. Perhaps it is too much to expect there ever to be the possibility of such a ‘recipe’, since one home cinema installation is usually different from the next, due to the efforts of architects and owners to create something quite new and original in each cinema room.
There are a few objective sound field properties, which are beyond question regarding their importance for what we call good or poor acoustics of a bespoke home cinema, namely the strenght of the direct sound, the temporal and directional distribution of the early sound energy, and the duration of the reverberation processes. These properties depend on constructional data, in particular on the
1. shape of the cinema room;
2. volume of the room;
3. number of seats and arrangement of the home cinema seating;
4. materials of walls, ceiling, floor, seating, etc.
In some future articles we will discuss these properties in more detail, in order to get a better understanding in home cinema design.