ROOM ACOUSTICS
Your Room
This is one of those areas that requires both a little back- ground to understand and some time and experimentation to attain the best performance from your system.
Your room is actually a component and an important part of your system. This component is a very large variable and can dramatically add to, or subtract from, a great musical experience.
All sound is composed of waves. Each note has its own wave size, with the lower bass notes literally encompassing from 10’ feet to as much as 40’ feet. Your room participates in this wave experience like a three dimensional pool with waves reflecting and becoming enhanced depending on the size of the room and the types of surfaces in the room.
Remember, your audio system can literally generate all of the information required to recreate a musical event in time, space, and tonal balance. The purpose of your room, ideally, is to not contribute to that information. However, every room does contribute to the sound, and the better speaker manufacturers have designed their systems to accommodate this phenomenon.
Let’s talk about a few important terms before we begin.
Terminology
Standing Waves
The parallel walls in your room will reinforce certain notes to the point that they will sound louder than the rest of the audio spectrum and cause “one note bass”, “boomy bass” or “tubby bass”. For instance, 100Hz represents a 10’ feet wavelength. Your room will reinforce that specific frequency if one of the dominant dimensions is 10’ feet. Large objects in the room such as cabinetry or furniture can help to minimize this potential problem. Some serious “audiophiles” will literally build a special room with no parallel walls just to help eliminate this phenomenon.
Reflective Surfaces (near-field reflections)
The hard surfaces of your room, particularly if close to your speaker system, will reflect some waves back into the room over and over again, confusing the clarity and imaging of your system. The smaller sound waves are mostly affected here, and occur in the mid and high frequencies. This is where voice and frequencies as high as the cymbals occur.
Resonant Surfaces and Objects
All of the surfaces and objects in your room are subject to the frequencies generated by your system. Much like an instrument, they will vibrate and “carry on” in syncopation with the music, and contribute in a negative way to the music. Ringing, boominess, and even brightness can occur simply because they are “singing along” with your music.
Resonant Cavities
Small alcoves or closet type areas in your room can be chambers that create their own “standing waves” and can drum their own “one note” sounds.
Clap your hands. Can you hear an instant echo respond back? You have
Rules of Thumb
Hard vs. Soft Surfaces
If the front or back wall of your listening room is soft, it might benefit you to have a hard or reflective wall in opposition. The ceiling and floor should follow the same basic guideline as well. However, the side walls should be roughly the same in order to deliver a focused image.
This rule suggests that a little reflection is good. As a matter of fact, some rooms can be so “over damped” with carpeting, drapes and sound absorbers that the music system can sound dull and lifeless. On the other hand, rooms can be so hard that the system can sound like a gymnasium with too much reflection and brightness. The point is that balance is the optimum environment.
Breakup Objects
Objects with complex shapes, such as bookshelves, cabinetry and multiple shaped walls can help break up those sonic gremlins and diffuse any dominant frequencies.
Solid Coupling
Your loudspeaker system generates frequency vibrations or waves into the room. This is how it creates sound. Those vibrations will vary from 20 per second to 20,000 per second. If your speaker system is not securely planted