390 CH APTER 18 Loudspeakers II: Objective Evaluations market, need to provide comprehensive anechoic data on their products. A few already do, and that is commendable. For loudspeakers intended for smaller listening spaces, there is no real challenge to acquiring meaningful data. A rea- sonable description of how the product performs needs to be the "price of entry" to this marketplace. It should not be up to the customer to discover information that should be publicly available. During the design of the product, this informa- tion was presumably available to the engineers who designed the product. If such data were not available to those engineers, then one is left to contemplate the competence of the source of the product. The descriptions of acoustical performance offered by many of the significant players in the loudspeaker busi- ness are simply insulting in their inadequacy. 18.3 COMPARING THE SUBJECTIVE AND OBJECTIVE DOMAINS Figures 17.2 and 17.3 showed that even primitive measurements and listening tests reveal a subjective preference for loudspeakers with frequency responses that are flat and smooth. These results were not published at the time; they were not really in the category of scientific data, but they provided a stimulus to do more. Interest was not lost, and activity continued, but it was many years before the vagaries of life and work conspired to produce the circumstances for the next big step. 18.3.1 Measurements It has been said before that measurements don't change. If they are done prop- erly, they can be repeated many times in many places and the answer is closely similar. Opinions are different. Not only opinions from different persons, but from the same person at different times and places. In audio, it has been long regarded as a "given" that personal taste in sound quality is variable, not really to be trusted in any generalized sense. In 1986, almost 20 years after the amateurish first tests described in Chapter 17, the author performed an elaborate subjective-objective investigation. It led, as discussed in Chapter 17, to a selection process for listeners. Of the 42 listen- ers who started the tests, only those results from the 28 most consistent are included in the following results. They all had hearing threshold levels within 10 dB of ISO audiometric zero at frequencies below 1 kHz and within 20 dB up to 6 kHz (Toole, 1986, Part 2). All of the listening tests were double-blind, of course; care was taken to avoid biasing the listeners. Listeners auditioned the loudspeakers in mono in groups of four, presented in different randomized combinations, until each listener heard each loud- speaker three to five times. After completing a questionnaire of subjective quali- ties, listeners were required to provide an overall "fidelity rating" on a scale of 10, where 10 describes the best imaginable and 0 represents the worst imagin-