I agree with those identifying the listening environment. It is critical factor that greatly affects sound quality. Obviously, the quality of the equipment, interconnects, power cords, speaker wiring, quality of AC power, conditioners, etc., all have an effect on the ultimate SOUND! I believe Bill Duddleston's work on developing equipment to address speaker room interactions is very important. To quote:
Loudspeakers and The Listening Room
A quick trip to your local high-end dealer can often leave one in bewilderment. If all these speakers are supposed to be accurate, why do they sound so different?
The answer lies primarily in the way the loudspeaker couples with the listening room. How it couples is a function of the power response and the physical properties of the listening room. The power response is related to the dispersion pattern of the loudspeaker and its amplitude response. Room properties include such factors as geometry, speaker, and listener placements, reflectivity of surfaces, and even ambient noise levels.
Reflections
Today, much attention is given to the way a speaker measures in an anechoic (reflection free) environment. While an on-axis pulse, FFT analyzed, can tell a speaker designer a great deal about how his speaker will behave at a distance of 2 meters in an anechoic chamber, what about the real world? Clearly these anechoic measurements weigh only the DIRECT ARRIVAL path to the listener.
A real listening room with walls, floor, and ceiling will have an infinite number of paths from the speaker to the listener. Most of the reflections from these surfaces have long path lengths, are diffuse and exhibit random phase, amplitude, and directionality cues. These reflections are usually not detrimental, and in most cases add to the “air” or “ambiance” in the recording. Reflections of this type are termed LATE REFLECTIONS.
But what about the short path reflections such as the inevitable floor reflection? These EARLY REFLECTIONS also tend to be the strongest of the reflections. Their single bounce pattern leaves very little opportunity for absorption or randomization, particularly problematic is the frequency range from 250 Hz to 1500 Hz. Such frequencies possess wavelengths whose dimension is similar to that of the reflected path- length, thus causing strong response anomalies. These frequencies also fall into the range where the human ear is most sensitive to the phase anomalies. (Current research indicates that human phase acuity diminishes sharply above 2 kHz. It appears that the hair-like transmitters (cilia) within the ear begin to scramble phase information when forced to change direction thousands of times per second. Amplitude information ultimately reaches the brain at these frequencies, but with unintelligible phase relationships.)
Early reflections can effect tonal balance, clarity, and image localization. The brain has a tendency to fuse these EARLY REFLECTIONS with DIRECT ARRIVALS into one smeared arrival. Unfortunately these troubling reflections are only about 6 dB weaker than the direct sound arrivals. In fact, most listening rooms will have average level differences of early to late sound of only 6 to 8 dB. Even more surprising is data demonstrating that only 15% of the reflections typically reaching the listener are from the sidewalls. The remainder consists primarily of the floor and ceiling reflections.
How do we deal with the dreadful floor reflection? Most of you have already done something by carpeting the floor of the listening rooms. Unfortunately, carpet is of little benefit below 1500 Hz.
We have found, as did Roy Allison a long time ago, that by elevating the lower midrange driver the proper distance off the floor, one can reduce mid-bass anomalies significantly. Then by establishing a crossover point to the woofer in the mid bass range, the responsive dip is virtually eliminated! This is owing to the averaging effect caused by the unique path lengths from the woofer and mid-woofer to the listener. This technique is effective in the Signature III, Focus and Whisper speakers, where multiple mid-bass drivers share the load.
What about the sidewall reflections? We have found that the biggest reason sidewalls cause a lack of clarity is that they are typically reflecting a signal that is inaccurate. Simply put, most loudspeakers exhibit horizontal dispersion that is not uniform.
How Does a Loudspeaker’s Dispersion Pattern Influence what we Hear?
Consider the classic 2-way speaker system utilizing a 1” dome and 8” woofer with a 2800 Hz crossover. While this speaker could appear near ideal on axis, when measurements are taken 30 degrees off axis laterally, it will in fact exhibit an 8 dB suckout near 2800 Hz, and an abrupt roll-off above 13.5 kHz. This undesirable beaming effect applies to all drivers and becomes a limitation when the wavelength of the radiated sound is smaller than the width of the diaphragm itself.
Such traditional design neglects the audible effects on power response and thus results in strong colorations in the reverbant field. In contrast each model of the Legacy speaker line is designed for specific application. Whether a corner sub, an on-wall rear speaker, a downward directed center channel or a forward firing tower, Legacy has taken great care in addressing directivity pattern and power response.
