Noise-cancelling headphones mystery
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Noise-cancelling headphones mystery
 
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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:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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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:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Elecraft mailing list
No noise canceling headphones will be effective against the high frequency noise of the KPA1500 fans. However, passive headphones can be very effective. The Radiosport makes the fans nearly inaudible. Not cheap, but neither is the KPA1500.
73, Scott K9MA ---------- Scott Ellington. K9MA --- via iPhone > On Dec 9, 2018, at 6:16 AM, eric norris via Elecraft <[hidden email]> 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:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Noise-cancelling headphones mystery
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In reply to this post by NK7Z
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)" <[hidden email]> 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:[hidden email] > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to [hidden email] > > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Noise-cancelling headphones mystery
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Noise cancelling headphones rely on the distance between microphone and
ear being a small fraction of the audio wavelength. At high frequencies, that will be impossible to achieve, and, even if you put in a compensating delay, the path to the ear is going to depend on the direction of the source. -- David Woolley Owner K2 06123. On 09/12/2018 16:40, CUTTER DAVID wrote: > ncies. 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 ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Noise-cancelling headphones mystery
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In reply to this post by K9MA
I fully agree with your comment on the Radiosport. Great headphones, virtually noise free, and on a price par with the better noise cancelling Bose/etc. Of course, when I have mine on, my wife has to kick the chair or slap my head to get my attention. Which may not be all bad? :-)
Grant NQ5T K3 #2091 KX3 #8342 > On Dec 9, 2018, at 11:15 AM, K9MA <[hidden email]> wrote: > > No noise canceling headphones will be effective against the high frequency noise of the KPA1500 fans. However, passive headphones can be very effective. The Radiosport makes the fans nearly inaudible. Not cheap, but neither is the KPA1500. > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by Elecraft mailing list
See if you can borrow a hi quality aviation noise cancelling headset to try out. I have the now discontinued Sennheiser S1’s which work extremely well in many situations including with a single engine open cockpit aircraft, riding mowers, tractors, field day, etc. They have the added nicety of high quality adaptive noise cancelling and efficient noise cancelling the mic audio as well. Don’t look for “Heil Hi Fidelity” response of the mic. You will sound like you are on an aircraft radio but they cancel noise better than anything I have tested.
There a number of sets out there that probably perform at that level. David Clark, Bose, Lightspeed and others... I just happened on to a great deal for the Sennheisers. All run above the $500 mark retail... KD4IZ Sent from my iPhone > On Dec 9, 2018, at 11:40, CUTTER DAVID <[hidden email]> wrote: > > 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)" <[hidden email]> 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:[hidden email] >>> >>> This list hosted by: http://www.qsl.net >>> Please help support this email list: http://www.qsl.net/donate.html >>> Message delivered to [hidden email] >>> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Noise-cancelling headphones mystery
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In reply to this post by Elecraft mailing list
On 12/9/2018 8:40 AM, CUTTER DAVID via Elecraft wrote:
> Noise cancelling that I've come across is limited to low/medium frequencies. Yes. Others have correctly identified the reason, but I'll go into a bit of detail for clarity. Noise cancellation works by amplifying a tiny mic on the outside of an earphone and feeding it to the headphones so that the acoustic output is out of polarity with the noise that is acoustically coupled to the ear. For deep cancellation, the sound from the mic and the sound that reaches the ear directly must be of precisely the same amplitude AND precisely the same phase (but out of polarity). This is particularly difficult to achieve, because 1) the headphones themselves attenuate the direct coupling of the noise to the ear, and that attenuation is not flat, and it varies depending on subtle differences in how the earphones fit/seal to the listener's head; 2) Phase is a variable, not a constant, and increases in direct proportion both to frequency and the distance that sound travels. 3) The small distance between the noise-sensing mic and the ear results in phase shift that increases with frequency. 4) The earphones themselves have non-flat phase response. 5) Directivity of both the microphone and the ear covered by the headphone is another variable. The above leads to these conclusions. 1) Low frequency noise is far easier to cancel than higher frequency noise. Noise produced by fans in the KPA1500 has significant higher frequency spectra. 2) Extreme care is needed in the design of noise cancelling headphones. I would expect products of serious audio companies like Sennheiser and Bose to be better performers. 3) I would expect to see new designs using DSP to introduce delay to reduce the time difference resulting from mic placement and equalization for non-flat amplitude and phase response of the total system. K9MA says that Radio Sport headphones effectively kill the sound. I have no problem believing that -- they're designed for use in high noise environments. But don't buy a pair until you've tried them on -- headphone comfort is a VERY individual thing that depends on the shape of our heads. Some contesting friends like them, so I've tried them on at several hamfests, and found them an instrument of torture. I couldn't imagine wearing them for even a few hours. 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: Noise-cancelling headphones mystery
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I find the RS60 very comfortable for long periods. I know others who do, and others that don’t. I have adjusted mine for ME. Which could lead someone else to find my specific headset uncomfortable (too tight, too loose) for THEM. You’re certainly right that the comfort of any headset is a very personal thing. I’ve tried more than one headset that came highly recommended, "most comfortable ever", and they just gave me a headache.
Grant NQ5T K3 #2091 KX3 #8342 > > > K9MA says that Radio Sport headphones effectively kill the sound. I have no problem believing that -- they're designed for use in high noise environments. But don't buy a pair until you've tried them on -- headphone comfort is a VERY individual thing that depends on the shape of our heads. Some contesting friends like them, so I've tried them on at several hamfests, and found them an instrument of torture. I couldn't imagine wearing them for even a few hours. > > 73, Jim K9YC ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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I find my RS60 to be comfortable, but sometimes wish they had a cooling system.
73, Scott K9MA ---------- Scott Ellington. K9MA --- via iPhone > On Dec 9, 2018, at 12:34 PM, Grant Youngman <[hidden email]> wrote: > > I find the RS60 very comfortable for long periods. I know others who do, and others that don’t. I have adjusted mine for ME. Which could lead someone else to find my specific headset uncomfortable (too tight, too loose) for THEM. You’re certainly right that the comfort of any headset is a very personal thing. I’ve tried more than one headset that came highly recommended, "most comfortable ever", and they just gave me a headache. > > Grant NQ5T > K3 #2091 KX3 #8342 > >> >> >> K9MA says that Radio Sport headphones effectively kill the sound. I have no problem believing that -- they're designed for use in high noise environments. But don't buy a pair until you've tried them on -- headphone comfort is a VERY individual thing that depends on the shape of our heads. Some contesting friends like them, so I've tried them on at several hamfests, and found them an instrument of torture. I couldn't imagine wearing them for even a few hours. >> >> 73, Jim K9YC > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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