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
Sent from Yahoo Mail on Android
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