mikebse2a3 Posted January 21, 2009 Share Posted January 21, 2009 Mark basically he had a very bad mode at 42Hz in his room and what Toole noticed in this room was that if he moved his listening chair he could of course find a spot that the sound became much improved. As in the real world would have it the chair's location was not in a location that was convient and he also knew that just as moving the chair could bring this problem under control so could he have moved the speakers to an area that would not have excited this mode but again due to real world considerations that wasn't an option either. Now earlier in the book Toole mentions that room resonances at low frequencies behave essentially as minimum-phase phenomena. So in Toole's problem room he decided to measure and verify and then experiment with a Parametric EQ tuned to specifically control this 42 Hz mode. After testing he basically found that Electronic equalization method's waterfall test versus the "positional" equalization(ie: when he moved his chair to a good sounding location but unacceptable otherwise) waterfall test were extremely similar and in fact both options were reported by him and other listeners over several months to sound remarkably similar in every respect and both were much better than the orginal condition. Toole also noted that the EQ method had the advantage of letting the listener sit in the listening location were the chair was prefered for that room. Acoustically, he also noted that with the EQ method he had reduced the amplitude by 14db at 42Hz and thus the woofers in effect did not have to work as hard and distortion was lower and even the system could play louder. He also noted there was much less energy everywhere in the room at 42Hz and this was noticable as improved sound quality at other listening locations. In summary he stated: The right kind of equalization sounds just fine, and electronics can provide an option equivalent to natural acoustical manipulations. Of course, it works best for a single seat. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ I believe this is a good example of how the history of bad EQing(because of wrong or inadequate equipment and wrong methods applied to situations has lead to people believing that EQing is bad and has no place in a high end system). Remember Richard (Coytee) mentioned how I had found and corrected a problem room mode that clearly was noticable at many locations in the room. At the time we were comparing some extreme slope networks on his Khorns and solving this problem had a very dramatic improvement in clarity and tonality IMO versus what was felt to be just a slight difference in sound due to the networks (to give some indications of the difference we were hearing) but because people have insisted you can't EQ room problems I believe he has had doubts about using it. Proper EQing can bring about some important improvements in a system(ie: loudspeaker/room/listener) but of course when it is misapplied it can easily worsen the sound. mike tn Quote Link to comment Share on other sites More sharing options...
jacksonbart Posted January 21, 2009 Share Posted January 21, 2009 Didn't Toole disprove the whole idea of a listener with a"Golden Ear" listner idea by proving people couldn't make distinctions between cables and the like in double blind tests? But listeners if trained to listen for it could notice small changes in frequency between equipment? Quote Link to comment Share on other sites More sharing options...
DrWho Posted January 21, 2009 Share Posted January 21, 2009 After testing he basically found that Electronic equalization method's waterfall test versus the "positional" equalization(ie: when he moved his chair to a good sounding location but unacceptable otherwise) waterfall test were extremely similar and in fact both options were reported by him and other listeners over several months to sound remarkably similar in every respect and both were much better than the orginal condition. I wonder how similar it sounded, and how sensitive our perception of decay actually is. I believe the EQ'd version should still have a slightly slower decay, so do you EQ for a flat frequency response or bring it down a bit so that the decay lines up? Or perhaps a compromise in the middle? I'm sure the magnitude of compromise depends a lot on the frequency and size of the room, etc...for instance, I would expect it to be more effective at the lowest mode than its first harmonic, and so forth... Quote Link to comment Share on other sites More sharing options...
gaspr Posted November 14, 2009 Author Share Posted November 14, 2009 Just curious if anyone else has read this book and what your impressions are... Quote Link to comment Share on other sites More sharing options...
Chris A Posted November 14, 2009 Share Posted November 14, 2009 This is a must-read resource. It has cleared up a lot of misconceptions and guessing. I'm still reading the thing...slowly...and making margin notes as I go along. It's that good. Chris Quote Link to comment Share on other sites More sharing options...
sunburnwilly Posted November 15, 2009 Share Posted November 15, 2009 What the hell is MAS?I know this post is almost a year old but I believe MAS was Dragonfyre's second coming . Also I needed to post to bookmark this thread . Quote Link to comment Share on other sites More sharing options...
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