Originally Posted by LarryChanin
It is possible to use third party measurements to approximate the Audyssey frequency response curves. However, since their fuzzy logic method of weighing the different measurement results is proprietary, one might be forced to use simple spatial averaging rather than the actual weighing technique that Audyssey uses. I would think the results could be close, but not exact.
Since MultEQ is for the most part merely fitting a flat curve with some high frequency roll-off, I doubt a lot of psychoacoustics is involved in that process. As you know considerable subjective listening tests and research was conducted in arriving at their equal loudness corrections used in Dynamic EQ, but Sean didn't use Dynamic EQ in his listening tests.
Other forum members have dabbled with measuring Dynamic EQ at various listening levels and the results show a family of curves that start to look like the Harman prototype frequency tilt that is preferred by the listeners.
Originally Posted by Kal Rubinson
Yes but a lot depends on what you want to measure.
1. Do you want to measure in order to confirm/critique that Audyssey has achieved its predicted result? If so, you can only do that by measuring response exactly as Audyssey does but that leaves open questions about phase/time/impulse issues.
2. Do you want to measure in order to confirm/critique Audyssey's actual results? If so, there are tools, including REW, ARTA, SMAART, TEF, etc., that will allow you to measure many parameters before and after. Of course, that means that you have to determine the significance of the differences.
It seems to me that it is only practical to choose the latter and not worry much about matching what/how you measure to Audyssey. In general, I would also think that having an independent measurement system (acoustical or psychophysical) is the best way to assess performance of any EQ system.
I agree, and would add that Audyssey does such a poor job of displaying their results that an independent measurement system is a necessity regardless of which of your objectives someone chooses to pursue.
With regard to confirming/critiquing Audyssey's overall effectiveness, it should also be emphasized that the intent of Audyssey's fuzzy logic approach to weighing results is to improve the sound quality at multiple listening locations without unduly impacting the sound quality at the primary listening location. So to test the effectiveness of this departure from approaches that use simple spatial averaging would require subjective listening tests in locations other than the primary location, as well as at the primary location.
Sean's objective was to rank how competing room correction products sound to trained listeners and to draw conclusions based on how they specifically measure with regard to frequency response. To do "apples to apples" comparisons all of Audyssey's frequency response processing, Dynamic EQ should be included in future subjective listening tests and objective measurements.
I didn't notice any other measurement parameters mentioned in the testing other than frequency response, but other measurements, such as time domain measurements, might be useful in ascertaining differences. It would also be instructive if a wider selection of content, including multichannel content with a full complement of speakers were included in future testing to supplement the monaural testing.