K3S Noise reduction Test
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EXACTLY RIGHT! The scientific study of how we hear and perceive sound
is called psychoacoustics, and is one of many important disciplines of the Acoustical Society of America. Early work at Bell Labs and at universities like MIT and Harvard became the basis for stereo. Some of the first published work was by Joseph Henry, whose name is on the unit of inductance in recognition of his invention of meters and motors. It was Henry who first observed (around 1850) that when the same sound is heard from two directions, the one that arrives first at our ears tells us where the sound is coming from. This fact is the basis of the Bell Labs stereo patent, and makes it far superior to the Blumlein work published a year or so earlier. 73, Jim K9YC On Wed,6/21/2017 1:14 AM, David Woolley wrote: > Noise reduction is about reducing subjective noise for the listener, > not about reducing some engineering measurement. An instrument is > likely to generate some very simple, or even pure tone, signal. With > the sorts of strategy used for noise reduction, and very aggressive > settings, you could obtain almost perfect results on such a signal, > but those same settings would make human speech completely > unintelligible. > > The big challenge for noise reducers is deciding what is human speech > and what is noise. That's much more difficult than identifying a pure > tone. ______________________________________________________________ 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 David Woolley (E.L)
David W. wrote Noise reduction is about reducing subjective noise for the listener, not about reducing some engineering measurement. I replied, David W. wrote An instrument is likely to generate some very simple, or even pure tone, signal. With the sorts of strategy used for noise reduction, and very aggressive settings, you could obtain almost perfect results on such a signal, but those same settings would make human speech completely unintelligible. I  replied, That’s true. My complaint is that there isn’t enough level settings. As soon as you select F1-1, the NR is already on the edge of being too aggressive. If the setting started at 0 or even 1 and the noise floor dropped in 5db increments, I wouldn’t have this discussion. Working in telecom for 30 years and in and in the DSP groups for 15 years, the single tone test is the only way I know to characterize the LMS algorithm. If you have a better test setup, please let me know. -- Jack WA9FVP- http://www.willcoele.com/radio_repair
Jack WA9FVP
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In reply to this post by Nr4c
nr4c. bill wrote, -- From: Nr4c [via Elecraft] [mailto:[hidden email]] But that knob varies a whole other range of NR. How hard is it to turn one knob 32 clicks? > On Jun 20, 2017, at 2:51 PM, Drew AF2Z <[hidden email]> wrote: > > The only thing I would change in NR is to make it easier to scroll through the settings. Currently you can only go through the 32 settings sequentially with the VFO-B knob, from 1-1 through 8-4. It would be nice if the VFO-A knob could be employed to increment and decrement the first parameter. > > For example: if you were on NR 1-3 you could scroll directly through 2-3, 3-3, 4-3, etc using the VFO-A knob. > > I don't know the details of NR but believe that all the n-1 settings are related to each other as a group; same goes for the n-2 settings, n-3, and n-4. So, it would make sense to be able to scroll through the "n" values when looking for the best noise reduction. > > 73, > Drew > AF2Z > > >> On 06/20/17 11:48, wa9fvp wrote: >> I did a comprehensive test of the K3S noise reduction system and uploaded the >> same document to the Elecraft_K3 Yahoo group. >> Elecraft_K3_NoiseReduction.pdf >> <http://elecraft.365791.n2.nabble.com/file/n7631913/Elecraft_K3_NoiseReduction.pdf> >> Here's what I concluded. >> Settings Fn-1 provides the least noise reduction. Fn-2 and Fn-3 noise >> levels are almost the same and one setting could be eliminated. Fn-4 >> provides the most noise reduction and having 3 settings, it would >> simplifying NR adjustments. The NR delays that is, F1-n through F4-n, could >> be added to the configuration menu. There are delay differences in the >> noise ripple but aurally, with a complex voice waveform, there’s no >> distinction between the delay settings. >> Don't get me wrong! I'm not that saying there's something wrong with the >> K3/K3S noise reduction. It works very well! I think there are too many >> settings and some can be eliminated. What are your thoughts? >> ----- >> Jack WA9FVP >> Sent from my home-brew I5 Core PC >> -- >> View this message in context: http://elecraft.365791.n2.nabble.com/K3S-Noise-reduction-Test-tp7631913.html >> Sent from the Elecraft mailing list archive at Nabble.com. >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qthnet/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://ww Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qthnet/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] If you reply to this email, your message will be added to the discussion below: http://elecraft.365791.n2.nabble.com/K3S-Noise-reduction-Test-tp7631913p7631952.html To unsubscribe from K3S Noise reduction Test, click here.
Jack WA9FVP
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Re: K3S Noise reduction Test
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Folks - Let's rest this thread for now as its exceeding our posting limit.
73, Eric List modulator etc. /elecraft.com/ On 6/21/2017 10:03 AM, wa9fvp wrote: > nr4c. bill wrote, > But that knob varies a whole other range of NR. How hard is it to turn one knob 32 clicks? > > 32 clicks but only 4 NR levels. The other settings are delays and mixed signals. There aren’t enough level settings. ______________________________________________________________ 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 Jim Brown-10
Jim Brown Wrote EXACTLY RIGHT! The scientific study of how we hear and perceive sound I remember something from the telecom days and I found this on the Internet. “The lowest discernible signal that can be heard by a human being is -90 dBm (800 or 1000 Hz)” It brings back something I heard in the early days when DSP noise reduction was first introduced to Ham Radio. At one of the Dayton Hamvention seminars, I don’t remember who that was, they said something to the affect “Noise reduction cannot pull an SSB signal out of the noise. It can however reduce the noise floor to a comfortable listing level’. I guess, that’s all we can hope for. PS; In order to reduce bandwidth, I try to cut previous posting from my replies. Sometimes I forget and for that I apologies. Jack WA9FVP
Jack WA9FVP
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In reply to this post by wa9fvp
I too would like the NR to use the A & B
knobs and even greater options with the B knob. I think I would find it much easier to select the right settings on the fly. Maybe user selectable in the next or upcoming K3/K3s update? 73, Gary KA1J ______________________________________________________________ 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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