Room Treatment
You have read all of the reviews, received recommendations from some of your most respected audiophile friends, spent countless hours auditioning equipment, and have finally assembled your dream system, but for some reason it still does not sound right. The bass is bloated the highs are piercing and the soundstage is non-existent. You scratch your head in wonderment and browse various chat forums on the internet to see if anyone else is experiencing your same problems. To your surprise you find that everyone has a different opinion and viewpoint on your equipment. How can that be? How can everyone hear so differently? Well, more often than not, the differences that everyone hears are not necessarily the equipment, but rather the influences of the room on the overall reproduction.
A large number of audiophiles do not realize the true importance of good room acoustics. No matter how terrific the electronics and loudspeakers are the room has the final say, which can be either fantastic or depressing. The dimensions of a room and whether it is open or closed can affect the bass response by either adding or subtracting bass. Correct placement of the speakers, listening triangle, and use of the woofer adjustment controls can help eliminate these problems. However, piercing highs or lack thereof may not necessarily be solved by just using level control on the tweeter, as overcompensating for this can lead to inaccurate reproduction of the input signal. Characteristics like these are often the result of room boundary reflections. It is not just the tweeter that suffers from this, as midrange performance can also be greatly affected, giving colored sound with collapsed soundstage characteristics. Most of the time echoes resulting from large unbroken wall surfaces are the culprits of these deficiencies. A simple test is to clap your hands while standing in the listening room. If you can hear an echo than most likely you will need to obtain some form of room treatment. Move around the room clapping your hands to gauge the variances in echo, which will give you an indication of just how much treatment is needed and where. As you know there are hundreds of books written about room acoustics and this guide is not about to go in to detail explaining how to do it right. However, if you would like to save some time researching, it is generally accepted that a listening room should have about 50% of the surfaces reflective and 50% of the surfaces absorptive. Keep in mind that normal household items can become part of this equation as carpeting, padded furniture, bookshelves with books, draperies, CD racks, vinyl racks, etc. all will contribute to aiding in the reduction of echoes.
Some simple starting considerations are to pay attention to first reflection points. These are the areas along the sidewalls where sound waves first bounce off before arriving to your listening spot. They are usually halfway between yourself and the speakers along the wall. The best way to find this spot is to imagine playing billiards or to use a mirror. Sit in your chair and have someone move a small mirror along the wall around this halfway point. The point where you can see the speaker in the mirror is the first reflection point. Seeing various parts of the speaker will also give an indication of what frequencies you are trying to tame, for example, seeing the tweeter means high frequencies and seeing the midrange means midrange and so on and so forth. This first reflection point will also relate to the ceiling and floors as well, so if you can perform the same experiments on these surfaces, the more accurate your room tuning will become. On the ceiling you can use acoustic tiles or acoustic damping pads made from foam, on the floor you could use shag rugs or small organically shaped decorative elements, and along the side walls you could hang acoustic panels or carpets or even decorative trees and plants to help diffuse the sound waves. Keep in mind that the lower the frequency you are trying to control the longer the wavelengths and the thicker the absorption material or deeper the diffuser must be.
For more professional results you should contact your local dealer and inquire about room treatment products as well as consultation services. The single best advice is to do your homework and check with people who have tried the room treatment products as well as the consultants.