Many people we speak with about designing a sound room have no idea where to start acoustically. Not only do they not understand acoustics and how the room influences their sound, but they don’t know how to go about planning to handle all the acoustical issues that the room will produce when you put energy into it. Most rooms are existing rooms that are now going to be a sound room. Some are new rooms that can be built from the foundation up.
First Things First
The first acoustical issue that must be addressed in all rooms no matter existing or new construction is low frequency energy control. In existing rooms we have a predetermined size we must deal with. Those room dimensions will dictate what low frequency issues we will be faced with. Since we can’t make the room larger to minimize low frequency issues, we make it smaller. We make it smaller by using powerful bass absorbers that absorb at high rates and levels of low frequency absorption in the appropriate room positions. In new construction and design, we have the flexibility of making the room dimensions more favorable from the beginning and can minimize low frequency issues by choosing the correct width, height, and length.
Reflection control from the room’s boundary surfaces or walls is our next acoustical concern. The direct sound from our loudspeakers is the sound we want to hear the most of. The direct sound is the sound that leaves our loudspeakers and travels in a straight line from our speakers to our ears. Unfortunately, or fortunately, depending on which school of thought one subscribes to that wanted, direct, sound has to be produced in a room and then the direct sound strikes all the room walls eventually and now we have direct sound and room sound. We want a balance of both room sound and direct sound. This balance can be achieved with time and patience, blended with current diffusion and absorption technologies.
Choosing the correct speaker size for the room is also critical. Bigger is not necessarily better. More energy introduced into a small volume room, will only make our low frequency issues larger. Side wall reflections will cause difficulty at the listening position and the reflections will cause acoustic distortions at the listening position by confusing our brains with the reflected/direct sound mix. Controlling and choosing the correct speaker size is especially critical when one is dealing with low frequency drivers such as a sub woofer. One must choose the correct sub woofer diameter to “match” the volume of the room. We don’t need a 12″ diameter driver in a small room where low frequency issues are always a concern.
Low frequency control can be managed with the appropriate room size. Speaker size should match “room size”. make sure all side wall reflections are managed correctly for proper sound stage focus and clarity.