[Elecraft] Noise-cancelling headphones mystery

[Dave Cole (NK7Z)]

As a guess, I would say the response of the mic used to derive the phase 
canceling audio does not adequately cover the audio noise spectrum of 
the 1500 puts out...  Thus it can't phase cancel very well...

That or your 1500 is filled with bad magic because it is supposed to be 
my KPA-1500 and it is mad at you.

73s and thanks,
Dave (NK7Z/NNR0DC)
https://www.nk7z.net
ARRL Technical Specialist
ARRL Volunteer Examiner
ARRL OOC for Oregon

On 12/9/18 5:16 AM, eric norris via Elecraft wrote:
> I have owned a pair of Heil noise-cancelling headphones for many years.  They worked very well to reduce the noise of my old AL-1200 amplifier, and the 5 fans on my cantankerous man-killer Henry 2002A EME amplifier.  However, they are completely ineffective against the KPA1500.  I bought a pair of Bose noise-cancelling headphones recently, and they work much better but are a bit tinny and eat batteries.
> My question for the audio experts on this list is why don't the Heils work with the KPA1500?  Does anyone have a recommendation for a pair of really good noise-cancelling headphones with a more flat response?
> 73 Eric WD6DBM
> 
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