SOUND QUALITY METHODS AND RATINGS EXPLAINED
Auditioning begins with preliminary trials, an extended running-in and warm-up period, plus informal trials with the partnering system, exploring the more obvious aspects, and seeking complementary combinations of audio components to see how to best understand the quality of the DUT, the device under test. Different shelves, platforms or feet can assist, while other important aspects include cables overall, including mains cables. An amplifier may sound bright with a given speaker and cable set. This is useful information but if other aspects of its potential are to be fairly assessed it is worth trying to fine-tune the system first. Preliminary descriptions of sound quality are developed in this phase.
These second stage involves powering up reference amplifiers, checking levels and absolute phase, and making comparisons, comparing and contrasting the many dimensions of sound quality. With reference scores pre established for the comparison products an idea of the special and overall merits of the DUT can be established. At this stage, given some practice, it fairly easy to determine a difference score for the test products.
The mental framework is one of percentages. If, when compared with a familiar reference which has a long established sound quality score of 30, the DUT is subjectively about 50% better; for example a balance of deeper soundstage, better reverberant field, sharper focus, more rhythm and listener involvement, crisper bass, sweeter treble, higher resolution, and these and other aspects are all weighed in the balance. On this basis the new product is rated 15 points better than the chosen reference and thus gets 45 marks. This will be a provisional score because one further step needs to be taken.
Consider that the final published score could be regarded as artificial, an illusion since you are unlikely to hear this full potential at a dealer, and will only hear it at home if you take the product to the practical limit. So there is a third stage in the judgement process which concerns powering down and disconnecting, and ideally physically removing, all the comparison and redundant source components from the test system. The DUT is now operated alone, free of unnecessary supply interference, digital noise from other components, physically well supported and located, in as optimal a system match as can be practically achieved. At this point a final sound quality score is confirmed, following extended listening with a variety of program and program sources, the best that could be optimally achieved.
Such subjective ratings inevitably have embedded in them the musical sensibility of the listeners, and here the test bias leans more to the involvement and entertainment aspects of sound reproduction, and where a beautiful sound and a big focused soundstage alone will not score at the highest level if the sense of drama, dynamics and rhythm is also unduly diluted.
It is unfortunate that there are many nice sounding products on the market where the designers have unduly focused on beauty and detail and seem to have quite missed the point about musical performance; these designs are good at reproducing the notes but fail to show the musicians working as a team.
If Hi Fi reproduction is rendered elegant but boring then we all might as well pack up now, as we inexorably head towards Musak performances, hastened by the advancing dissemination of MP3 lossy coding and its ilk.