Originally Posted by LarryChanin
Yes, and as Chris mentioned many of us are constrained by existing room dimensions and we also have limited flexibility in placement of seating and speakers in that fixed space. Therefore, placement optimizers may have limited effectiveness for many of us.
However, I'd like to return to the earlier question that was posed, "Why do subjective listening results occasionally sound better with different Audyssey microphone configurations?" In addition to the theory that differing amounts of comb filtering effects at the microphone locations may effect the degree to which the modal response is corrected, I have another theory.
If we happen to have microphone locations where the majority are situated near modal peaks rather than modal nulls, then Audyssey will have more resources available to flatten the response, i.e. -20dB for peaks vs. +9dB for nulls. So the resulting composite fuzzy logic weighted response for situations with more peaks would likely be flatter than those with more nulls. Now, this assumes that all of the microphone locations are still near an actual seating location and are therefore providing relevant data. In such cases perhaps the WAVES worksheet might provide some guidance where those peaks are likely to be located for the first three axial modal frequencies for each room dimension.
Just an idea Larry. I don't understand the science of this stuff like you, but I am a DIY tweaker who has engaged in much subjective listening tests involving different calibrations in my room. For me, it is all about what sounds best to my ears. My room is my room, and that is not changing. So playing around with different measurement patterns and sizes was my option....oh, and the 4 dsp's on my sub.
I found that Audyssey Pro is incredible level of repeatabilty. When I did four calibrations using the 12 point pattern.....one for each dsp...I found remarkably similar before and after graphs for all speakers (except the sub, it showed some small variation). However the performance of my subs was not uniform. Obviously Audyssey cannot negate a dsp in a sub completely...or else all 4 calibrations would sound the same in terms of the bass. And I am not saying this is a flaw of Audyssey. In my case the results were wonderful for each dsp.....but absolutely oustanding for one in particular. When I looked at the graphs, two dsp calibrations were showing ruler flat after graphs for the subs.....but my favorite dsp calibration was like a flat line with very small intermittent bumps. This dsp calibration yielded the strongest bass response, and this was most pleasing to me. The graphs showed it to be louder at 20 hz as well. So in this case it was really a matter of selecting the best dsp for my room. It was just a simple 12 point cal with Audyssey.
My point is that these dsp's can be likened to irregularities in our particular rooms dimensions, etc. Doing multiple calibrations each with some variation of the mic placement, and them comparing the results with graphs, recommended crossovers, and most importantly listening tests can yield fruit for some. This is a very practical method...and the end result is always what sounds best to you, not what should theoretically sound the best.
One more thing found cool was that I did one calibration where I did rows of measurements that went right to left in my listening area. After each row I saved the calibration, and generated graphs. So after my seven row calibration I had 7 different cal files, and 7 sets of data with which to see how mic movement in my room effected speaker responses and crossovers. It was fun and informative. It did get me thinking that it was important to not have too great a number of measurements in a certain slice of the room, etc. But everything leads back to Audyssey knows best! Damn, why are they so smart. I could have just followed the setup guide. Dohhhh! But then what would be the fun in that. I always have to learn the hard way. And the fun way.