Here’s the actual John Curl quote for my post above.
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"The test equipment is almost always brought on line to actually measure problems the ear hears. So we’re always working in reverse. If we do hear something and we can’t measure it then we try to find ways to measure what we hear. In the end we invariably find a measurement that matches what the ear hears and it becomes very obvious to everybody. "
Yeah, it was obvious to everybody! Once they found a way to measure it.....
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Also, we couldn’t use mylar capacitors, which are fairly efficient coupling capacitors. While mylars are fairly efficient from a size and cost point of view, we realized they have problems with dielectric absorption. I didn’t believe it at first. I was working with Noel Lee and a company called Symmetry. We designed this crossover and I specified these one microfarad Mylar caps. Noel kept saying he could ’hear the caps’ and I thought he was crazy. Its performance was better than aluminum or tantalum electrolytics, and I couldn’t measure anything wrong with my Sound Technology distortion analyzer. So what was I to complain about? Finally I stopped measuring and started listening, and I realized that the capacitor did have a fundamental flaw. This is were the ear has it all over test equipment. The test equipment is almost always brought on line
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to actually measure problems the ear hears. So we’re always working in reverse. If we do hear something and we can’t measure it then we try to find ways to measure what we hear. In the end we invariably find a measurement that matches what the ear hears and it becomes very obvious to everybody.https://parasound.com/pdfs/JCinterview.pdf
Years ago, there was a time when people used to think you could have a two- or four-foot path difference between loudspeaker components; like the Klipschorn, for example. Everyone said this time difference was inaudible, and it didn’t really matter because Bell Labs’ research, Ohm’s law of acoustics, Helmholtz and all these other people believed that the ear was completely insensitive to phase. So it didn’t matter how you built the speaker as long as it sort of averaged out sort of okay in the room. You could take five microphones and measure them all together, if that measured out okay within a few DB’s then heck with it. Well, that really isn’t true and of course when stereo came along all of a sudden you had these big Klipschorns and they wouldn’t image for anything. At least that was my personal experience. I owned them and I was a believer too. Then I started measuring them and I said ’oh my goodness, this is a problem.’ The late Richard Heyser tried to tell people that a two foot path difference might be audible. People were going crazy and saying this was impossible and it was a big controversy. Now, of course, no fool would design a speaker with a two- or four-foot path difference. John Dunlavy was very outspoken on the Internet this week, criticizing a loudspeaker that wasn’t completely phase aligned to within one inch. See how we change. I don’t disagree with John Dunlavy, although I do think he is overstating his case in this particular one. But, there was a time when we didn’t. The same thing happens with capacitors. There was a time when we didn’t know better and we just used any old capacitor as long as it had the right values.
"The test equipment is almost always brought on line to actually measure problems the ear hears. So we’re always working in reverse. If we do hear something and we can’t measure it then we try to find ways to measure what we hear. In the end we invariably find a measurement that matches what the ear hears and it becomes very obvious to everybody. "
Yeah, it was obvious to everybody! Once they found a way to measure it.....
.