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#1
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![]() http://www.stereophile.com/reference/1104red/ more specifically http://www.stereophile.com/reference...ed/index3.html "Although the initial fuss that accompanied Ray Kimber's 1999 launch of DiAural-the proprietary speaker-crossover technology developed by Eric Alexander-has died down, the fact remains that it was and still is promoted as a means of canceling the Doppler distortion introduced by microphones: "Doppler Decoding," in DiAuralspeak. To my knowledge, however, this claim has never been challenged in the audio press." "...for a microphone to introduce significant levels of Doppler distortion, its diaphragm would have to undergo large excursions-of the same order as the loudspeaker diaphragm, if cancellation is to be feasible. In fact, microphone diaphragm excursions are minuscule. I asked Stephan Peus, president of development at Georg Neumann GmbH, to provide me with some representative figures. He e-mailed back a document, "Some Amazing Facts with Condenser Microphone Capsules," which quotes the diaphragm excursion for Neumann's KM 184 microphone (a miniature cardioid) as being just 10 nanometers-that's four-tenths of a millionth of an inch, or about a 40th the wavelength of blue light-at an SPL of 94dB. Compare this with the 7.5mm peak excursion required to generate this SPL at 100Hz in free space and at 3m (10') listening distance, using a drive-unit of 200mm (8") effective diaphragm diameter. The two figures differ by a factor of 750,000! Depending on their mechanical characteristics, the diaphragms of other capacitor microphones may undergo larger excursions, but their displacements will still be orders of magnitude smaller than a loudspeaker cone's IOW, when Kimber snowed Stereophile about his abilities to correct Doppler Distortion in microphones, he was talking trash. I notice that the origional offending article has been expunged from the Stereophile web site. It used to be located at http://www.stereophile.com/shownews.cgi?416 . Here are quotes from the missing article and my comments about it that were posted here at that time: http://groups.google.com/groups?selm...u tput=gplain -------start long quote that embeds quotes from the Stereophile web article that now seems to have gone missing http://www.stereophile.com/shownews.cgi?416 says: "Five weeks ago we reported that Ray Kimber, of Kimber Kable fame, and his financial partner, Bruce Bastion, were in the process of bringing a new loudspeaker technology to market. DiAural, as they've named the technique, is claimed to eliminate what Kimber calls Doppler-encoding distortion---the modulation of high frequencies by low frequencies of higher amplitude." This roughly corresponds to the classic understanding of Doppler distortion. W/R/T classical understandings of how to reduce FM distortion in speakers, this article seems to make some false claims, such as "According to Kimber, this encoding takes place in the microphone, survives intact throughout the recording and playback chain, and, if left undecoded, seriously detracts from any audio system's verisimilitude." Actually, Doppler distortion is due to velocity and changes in velocity. Speakers like the Bose 901 are specially exposed to it because their woofers and tweeters are the same driver. When the speaker's cones travel at high velocities to produce bass, treble is FM modulated by the Doppler effect. If treble is reproduced by a different cone, or if the speaker cone is prevented from attaining a high velocity, then doppler is greatly reduced. Thus, the classic two-way speaker system has greater resistance to Doppler distortion than a single-way. Also, this means that one of the benefits of having a subwoofer is reduced Doppler distortion. As a rule, microphone diaphragms don't move fast enough to cause doppler distortion. Ever see a microphone diaphragm stroke like a small woofer being driven with heavy bass? Nope - most mics would be physically damaged if they tried to do that! Therefore, the "coding" mentioned here is unlikely to happen. "The DiAural technique, developed by designer Eric Alexander, performs decoding at the speakers themselves, using a couple of common parts configured in a novel way that enables a woofer and tweeter (or woofer, midrange, and tweeter) to "talk back" to each other, freeing them to jointly produce sounds more like those that originally impinged on the microphone." Sounds like low slope crossovers or some other technique that reduces the isolation betwen the drivers. This is old news, and generally found to be the exactly wrong thing to do if the goal is to minimize Doppler distortion. "The DiAural circuit replaces the traditional crossover network, which means the drivers are connected directly to the amplifier. All of which made for an interesting telephone discussion I had with Kimber before writing this story." If the speakers are "connected directly to the amplifier", then there is no crossover network. This is actually the worst case for creating Doppler distortion. -------end long quote that embeded quotes from the Stereophile web article that now seems to have gone missing |
#2
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Arny Krueger wrote:
I notice that the origional offending article has been expunged from the Stereophile web site. Yeah. They're probably scared ****less that you will once again "expose" them, etc, so they frantically expunge and expunge away, and run around the office screaming, and ... ah wait, here it is: http://www.stereophile.com/news/10416/index.html |
#3
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Fella wrote
Arny Krueger wrote: I notice that the original offending article has been expunged from the Stereophile web site. Yeah. They're probably scared ****less that you will once again "expose" them, etc, so they frantically expunge and expunge away, and run around the office screaming, and ... ah wait, here it is: http://www.stereophile.com/news/10416/index.html I'm expecting Absolute Sound would be next on the hit list. |
#4
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"Fella" wrote in message
Arny Krueger wrote: I notice that the origional offending article has been expunged from the Stereophile web site. Yeah. They're probably scared ****less that you will once again "expose" them, etc, so they frantically expunge and expunge away, and run around the office screaming, and ... ah wait, here it is: http://www.stereophile.com/news/10416/index.html Thanks for pointing this out. It did not come up when I searched the Stereophile site for "Diaural". |
#5
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"Arny Krueger" wrote in message ...
http://www.stereophile.com/reference/1104red/ I notice that the origional...article has been expunged from the Stereophile web site. Not at all. You can find it at http://www.stereophile.com/news/10416 . It is also linked in the Keith Howard article. John Atkinson Editor, Stereophile |
#6
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Arny Krueger wrote:
"Fella" wrote in message Arny Krueger wrote: I notice that the origional offending article has been expunged from the Stereophile web site. Yeah. They're probably scared ****less that you will once again "expose" them, etc, so they frantically expunge and expunge away, and run around the office screaming, and ... ah wait, here it is: http://www.stereophile.com/news/10416/index.html Thanks for pointing this out. It did not come up when I searched the Stereophile site for "Diaural". Here is an urban legend coming your way krueger, highly relevant: Subject: Fabulous bit of historical knowledge Ever wonder where the word "****" comes from. Well here it is: Certain types of manure used to be transported (as everything was back then) by ship. In dry form it weighs a lot less, but once water (at sea) hit it. It not only became heavier, but the process of fermentation began again, of which a by-product is methane gas. As the stuff was stored below decks in bundles you can see what could (and did) happen; methane began to build up below decks and the first time someone came below at night with a lantern. BOOOOM! Several ships were destroyed in this manner before it was discovered what was happening. After that, the bundles of manure where always stamped with the term "S.H.I.T" on them which meant to the sailors to "Ship High In Transit." In other words, high enough off the lower decks so that any water that came into the hold would not touch this volatile cargo and start the production of methane. You are also (almost) an urban legend Krueger and I would not be too much surprised and even less flabbergasted to find out that sometime around 2100 - 2150 when people are listening to some bad music, or bose speakers, etc, and saying "gawd .. this sounds like kroog!" and stroies about the origin of kroog would float around in the internet of that time. BTW: In them DBT's you taut about constantly is there a neutral third party validator of some sorts inspecting that the sources blind to both the ubject and the performer of the test are *really* the sources they should be? If so, I am ready to take the challenge: my current system and the music I listen to.. Only variable to change would be the speaker wires I use currently against radio shack 12 gauge lamp cords. I bet I hear the difference *every single time* .. ![]() |
#7
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![]() "Fella" wrote in message ... Arny Krueger wrote: I notice that the origional offending article has been expunged from the Stereophile web site. Yeah. They're probably scared ****less that you will once again "expose" them, etc, so they frantically expunge and expunge away, and run around the office screaming, and ... ah wait, here it is: http://www.stereophile.com/news/10416/index.html Tsk, tsk. Is Google lying to Arny again? |
#8
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"Arny Krueger" said:
I notice that the origional offending article has been expunged from the Stereophile web site. Yeah. They're probably scared ****less that you will once again "expose" them, etc, so they frantically expunge and expunge away, and run around the office screaming, and ... ah wait, here it is: http://www.stereophile.com/news/10416/index.html Thanks for pointing this out. It did not come up when I searched the Stereophile site for "Diaural". You shouldn't spell that "diarrhea". -- Sander de Waal " SOA of a KT88? Sufficient. " |
#9
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![]() "John Atkinson" wrote in message om... "Arny Krueger" wrote in message ... http://www.stereophile.com/reference/1104red/ I notice that the origional...article has been expunged from the Stereophile web site. Not at all. You can find it at http://www.stereophile.com/news/10416 . It is also linked in the Keith Howard article. SPLÄT!!! |
#10
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![]() "George M. Middius" wrote in message ... Fella said: BTW: In them DBT's you taut about constantly is there a neutral third party validator of some sorts inspecting that the sources blind to both the ubject and the performer of the test are *really* the sources they should be? If you want the viewpoint of the MasterBorg, here's one example: http://makeashorterlink.com/?H58C419D9 I get the feeling he masturbates a lot. Cheers, Margaret |
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