Noise cancelling that I've come across is limited to low/medium frequencies. If your hearing takes you higher, the noise-cancelling has finished by then. This is probably not the ability of the sensing mic but the circuitry and/or room acoustics, echo, etc. I'm a little out of date on the subject but that's probably the essence of it. David G3UNA
> On 09 December 2018 at 15:26 "Dave Cole (NK7Z)" <d...@nk7z.net> wrote: > > > 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 > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:Elecraft@mailman.qth.net > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to d...@nk7z.net > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to d.cut...@ntlworld.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
