After spending a few days pouring over a copy of High Performance Loudspeakers by Wiley Publishing, here are some useful details elucidated. Based on these aspects, one knows what to look out for, and at the same time select test tracks or music which may very well test one or two of the factors.
[subjective Frequency Balance]
Treble, Mid, Bass : Low, Mid and High, deficiency or excess to be taken note of (Slight, Moderate, Severe)
[Rating of Sound Quality]
1. Clarity (Very Unclear, Rather Unclear, Midway, Rather Clear, Very Clear)
2. Fullness (Very thin, Rather Thin, Midway, Rather Full, Very Full)
3. Spaciousness (Very Closed, Rather Closed, Midway, Rather spacious, Very)
4. Brightness (Very Dull, Rather Dull, Midway, Rather Bright, Very Bright)
5. Sharpness (Very Sharp, Rather Sharp, Mid, Rather Soft, Very Soft)
6. Absence of Extraneous Sound
7. Fidelity (Very Bad, Rather Bad, Midway, Rather Good, Very Good)
[Definitions on Spatial Quality]
a) Definition of the sound images
Refers to the extent that different sources of sound are spatially separated and positionally defined. Images should not move as the pitch of music rises and falls. The size of the image should be appropriate to the source of the sound.
Continuity of Sound Stage
Is the display of sound images continuous, left to right, or are there illogical groupings of images, with large gaps in between? Is the reverberationuniformly displayed or is it concentrated in strange places?
c) Width of Sound Stage
Refers to the left right display of sound images. The response scale represents the one infront of you in this room. Mark on it the left and right limits or the boundaries you haer. Do not include vague reverberant sounds, only those of the orchestra.
d) Impression of the distance of Depth
Should be judged on the basis of a satisfactory impression of instruments at various distances. An unsatisfactory reproduction would have all of the instruments at one distance (two-dimensional), or some of them too close, or too far, and so on.
e) Abnormal Effects
Refer to the spatial sensations that do not occur in common experience. For example its possible for some sounds to appear to stretch between you and the screen, perhaps even some of the sound will appear insode your head. Other sounds may appear to have no location, when you know the instrument should be precisely located.
f) Perspective
Refers to your general impressions of the experience. A good reproduction of a good recording with natural room or hall acoustics should suggest that "you are there" at the performance, complete with a sense of the enveloping ambient sound. A less perfect reproduction could separete you from the performance, giving the impression that you are "close, but still looking on". In a worst still reproduction, it may seem that you are listening through an opening between the loud speakers. It is as though you were "outside, looking in" - there is no impression of being within the ambient sound. Other recordings may appear to transport the musicians to the listening room, "they are here". The ambience is that of the listening room, and the instruments sound close. Still other recdordings are created as abstract special effects, with no attempt to simulate a realistic experience.
[Definitions on Sound Quality]
a) Clarity/Definition
Refers to the ability to hear and distinguish different instruments and voices within complex orchestrations. The individual notes should also be distinguishable, with well-defined attacks, not diffused or muddled.
Softness
Refers to the quality of high frequency sounds. These should be smoothly natural, neither overly subdued and mild nor excessively hard, shrill, strident nor sharp.
c) Fullness
Refers to the quantity of low frequency sounds and their balance with respect to the middle and high frequency sounds. Good sound should neither be too full nor too thin.
d) Brightness
Refers to the balance of the high frequency sounds with respect to the middle and low frequency sounds. Good sound should neither be goo bright nor too dull
e) Pleasantness
Is an overall rating that concentrates on the pleasantness or lack of aggravations and annoyances in the reproduced sound
f) Fidelity
Is the overall rating that describes how closely the reproduced sound approaches your impression or recollection of the original or "perfect" sound. This is the one rating that sums up the previous analytical sound quality ratings. The rating of 10 represents perfection, a telephone may score between 0 and 1, whereas a small portable radio might score 2 or 3.
[Coloration]
Characterization----------------------------
Boomy - 50-80 Hz
Chesty, plummy - 100-150hz
Boxy, Hollow - 150-300hz
Tubelike, Tunnelly - 400-600hz
Cuplike, Honky - 700hz-1.2khz
Nasal, Hard - 1.8-2.5khz
Presence, upper hardness, wiry 2.5khz-5khz
Sharp, metallic, sibilant - 5.0-8.0khz
Fizzy, Gritty - 10-15khz
