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Guru of Grounding
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re: Active Noise Reduction: Can you really be within one percentage point of perfection?
Guru of Grounding   5/6/2010 3:12:14 AM
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Ahh, marketing - the art of deception by obfuscation or omission (in the name of appealing to the general public)!! For Jon_B's information, both the Volt and Bel are units derived from proper names Count Alessandro Giuseppe Antonio Anastasio Volta and Alexander Graham Bell, respectively.

timbo_in_test
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re: Active Noise Reduction: Can you really be within one percentage point of perfection?
timbo_in_test   4/30/2010 8:00:17 PM
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I'd write dB and mV - but I can't remember ever writing either out longhand! If you need to explain what meant by a mV you may be writing for the wrong audience (or do I mean readership?), if you need to explain dB you problably dispair at the inadequacy of the educational system! I do remember several years ago giving a presentation in a lecture theatre that was fully equiped by an active noise cancellation system; it was an intriguing and slightly weird experience. I had to give my presentation to a technician in the control room and the system had a monitor speaker that could be switched to reproduce the subtracted sound. This was a multichannel system and I started to wonder about the possibility of building a multichannel system that could monitor individual conversations anywhere in the auditorium. Has anyone ever done this?

Marcel..2
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re: Active Noise Reduction: Can you really be within one percentage point of perfection?
Marcel..2   4/28/2010 9:21:02 AM
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So what, Job_B...maybe it differs in some odd corners in the world, the US for example...any "relevant" comments to throw in?

Jon_B
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re: Active Noise Reduction: Can you really be within one percentage point of perfection?
Jon_B   4/28/2010 8:07:41 AM
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The author's nomenclature made me cringe. I was taught that it's decibels and millivolts, not deciBels and milliVolts - only the abbreviation has a capital letter when the unit is named in honour of a person. http://ewh.ieee.org/soc/ias/pub-dept/abbreviation.pdf http://physics.nist.gov/cuu/pdf/sp811.pdf

Frank Eory
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re: Active Noise Reduction: Can you really be within one percentage point of perfection?
Frank Eory   4/22/2010 8:07:55 PM
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This was an interesting refresher on the definition of the dB as it is used in electronics and in acoustics. The author's implication about the dishonesty of such marketing relies solely on his perceived lack of understanding of dBs vs. percentages by the consumer. I don't believe that such a lack of understanding is very prevalent in the world of audio, and certainly not among audiophiles. Imagine if the topic was THD instead of noise cancellation. No audiophile would be impressed by a THD of 1%. This is just another way of saying that in some contexts, being within 1% of perfection just isn't terribly impressive performance.

bcarso
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re: Active Noise Reduction: Can you really be within one percentage point of perfection?
bcarso   4/22/2010 4:57:08 PM
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Not a bad little piece. Some references would help, and the man's name was Stevens, not Stephens. A wonderful remembrance can be found here: http://books.nap.edu/html/biomems/sstevens.pdf



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