Originally Posted by sdurani
I posted the B&K graph from 1974 to demonstrate that listener preference hasn't changed. Anyone comparing it to Olive's paper from a quarter century later will notice that both curves were smooth and downward tilted. The similarity also demonstrates that listener preference was not tied to products, since a quarter century of separation meant that different products were used, even though listener preferences remained consistent.
The above post shows considerable ignorance or outright distortion of the actual context in which the cited frequency response plot was presented.
The earliest and closest source of the plot you've been posting that I can find is:
There is also an 1974 AES paper but it is very similar.
The associated text is:
"The closer evaluation of these curves concern the following two criteria. First, the curves should be as smooth and straight as possible, indicating that all frequencies are reproduced at approximately equal level. Secondly, primary emphasis should be given to the 60 Hz to 6 kHz range.
When music is recorded under farfield conditions, it will contain a suit*able mixture of direct and reflected sound, and the curve ought to be absolutely flat in that case.
This is true for recordings, for instance, made with two B &K condenser mi*crophones in the far-field.
However, since most recordings are made as a combination of nearfield and far-field information, the curve should boost a little at low frequencies and roll off a little at high frequencies. A suitably shaped curve is shown in Fig.5.
In fact the abstract of the paper says it is about measurement technologies, not listener preferences
This application note will describe the measurement possibilities, and it will show some results of the methods and compare them with re*sults obtained by listening tests.
Five loudspeakers in three different rooms and a test team consisting of five critical listeners were used.
That would be 2 listening rooms and an unknown number of listeners more than Harman used, no> ;-)
If you actually read the paper, the diagram that you have been hanging your argument about the time-invariant nature of shaped room curves on has nothing to do with a representative survey of consumer preferences. It is presented in a context where the ideal was that system response curves should be "...as smooth and straight as possible".
The shaped curve was justified by generalizations about the prevalent recording technology in 1974 which was as we all should know in the pre-digital age. The prevailing recording technology has changed greatly since then, both in terms of media and methodology. Modern recordings are overwhelmingly made in the near field. A more pronounced curve would seem to be in order for use with modern recordings.
And whoops, does that not indicate that there has been a great sea change in consumer preferences since 1974?