Here's a philosophical question. To get a good stereo you have to listen critically. After purchasing, the experts give the advise to "turn off" the critical listening and just sit back and enjoy the music.
Bit if you have picked a system by the method of critical listening and one which sounds good when listened to critically, how can you do this? It's a "critical listening system", not an "enjoy the music system" after all. |
AES PAPER EXCERPT Copyright Jon M. Risch, 1991, 2000. All rights reserved. Don't try to do too many listening trials at one sitting.
Listen to the same section of music, no longer than a minute,
preferably about 45 seconds long, no shorter than 30 seconds. Repeat it for each set of trials exactly. When moving on to a new set of trials (ABA), use a fresh section of music, or rotate several different sections through so that you are not listeneing to the same musical segment over and over, it is too easy to become overlyt familiar and therefore bored with the selection if too many repeats occur in a short time frame.
CONCENTRATE while listening, as listening for comparison purposes is not the same as listening to music for pleasure. You must be in an analytical mode at all times. This will take some practice. Casual listening will not pick up on anything but major differences.
Use a set defined pattern of component switching. Instead of just switching back and forth between components being compared, listen to A, then B, then A. If doing a comparison that will not be reversable (or readily reversable), such as coating a CD with green ink around the edges, use an A, A, then B pattern, or in the case of the CD, listen to it twice, THEN coat it and listen again.
DO NOT keep switching back and forth, A, B, A, B, A, B, as this WILL lead to listening fatigue quite quickly. Listen just a few times VERY INTENTLY, and make them count. Use the suggested method for listening to details below.
If you wish to make this a blind test, have the forced choice X at the end of the chosen sequence, e.g., A, B, A, X. OR A, A, B, X
Obviously, if you wish to perform the comaprison blind, some assistance will be needed.
Do not use switchboxes, tape loops, etc, BUT swap cables or cables to the components. Keep the volume control the same, and switch temporarily to a dead source to avoid any switching transients when swapping cables.
Finally, do not take notes or talk to others during the trails, wait till after the whole session is done, and you have made you choices or written down your notes. Focus on the task at hand during the musical segment playback, and take mental notes of what is going on.
AES PAPER EXCERPT
4.4 What To Listen For During Musical Test Passages
4.4.1 General
Focus on specific musical events within the musical segment, such as a cymbal crash or a specific phrase in the vocals, etc. Listen for different aspects at different points within the music, but try to limit your selection of specific items to be listened for a second time around. Beginners should limit themselves to just one or two musical events to remember from test run to test run, until practice has improved their audio memory and concentration. With practice and experience, 3 or 4 musical events can be examined from run to run.
4.4.2 Suggested Specifics To Listen For
Low Level Detail - Listen for the presence of minute details that are on the verge of getting lost in the midst of the rest of the music, such as subtle string noises, hall ambience, the breathing of the musicians, or even air conditioning noise recorded along with the music. These low level details are some of the first musical specifics to suffer with less than top quality equipment.
Transient Impact - Listen to the transient events in the music. Do they have a razor sharp sense of impact? An 'over before they are started' Kind of effect? Or are they smeared and drawn-out in time? Live musical transient events have virtually no smear or blurring.
Bass and Treble Quality - listen to the quality of the bass
and treble, not just how much of it there is, but how clear are the notes and sounds? Solid, tight bass notes with distinct pitch definition are in contrast to loose or boomy bass notes hard to pin down in pitch. There may be an apparent extension of low frequency response, a sense of musical foundation provided that is absent from the other component. Is the treble region sweet, clean and clearly delineated, or is it hard, hashy and distorted? An apparent extension of high frequency response typically doesn't sound like more high frequencies, but as though the music had an airy quality to it.
Stereo Spatial Phenomena - many subjective listening tests will be performed in stereo (or perhaps more appropriate: 2 channel reproduction) and therefore will include some spatial or pseudo spatial information. Theoretically, if both channels are changed by a component in the same way, then very little effect should be noted on true stereo spatial information. However, due to the fact that much of modern music has it's 'stereo' generated artificially in the studio, based on some rather crude level, phase, and time manipulations. it takes rather less deviation from linearity to disturb something even as seemingly solid as the pseudo-monophonic image generated in such manner. Listen for image shifts of back-up vocals, and shifts in the apparent position of a specific instrument from component to component, as well as shifts in the overall soundstage character of the musical passage.
Overall Tonal Balance - This has traditionally been the most questionable of changes to listen for, as a 'simple' linear error, such as a minor frequency response difference, can be responsible for the difference heard. It is, however, the most powerful and useful change to listen for when there is every reason to believe that the frequency response has not been changed to a significant degree within the audio band. Evaluation of most IC chips (those suitable for audio use according to their specifications) would be a good example of this type of situation: substitution of one IC chip for another in an audio component, say the output stage of a CD player, normally will not alter the frequency response significantly. If a change in tonal balance occurs when switching the IC chips in and out of the unit, then it is very likely that the tonal change is due to some difference in the signal handling accuracy other than frequency response errors. Of course, the frequency response should be checked to verify that it does measure 'flat'.
Another example would be listening to interconnect cables. In most modern sound systems, the substitution of one grade or type of line level interconnect cable will not significantly affect the measured frequency response within the audio band, so that if tonal balance changes are heard, they are most likely to be due to some other factor associated with the cable itself, for instance, dielectric effects of the insulators.
It must be pointed out that there are always 'special' cases where the above assumption will no hold, such as an IC chip not truly suited for audio use that actually does affect the audio band frequency response, or interconnects used with equipment with a very high output impedance (some tube gear) that will roll-off the high frequencies with certain high-capacitance cables. |
