Try the AFX button on the K3, to change the audio phase.
On Thu, Nov 14, 2024 at 11:51 PM Jim Brown <[email protected]> wrote: > On 11/14/2024 1:15 PM, Bob McGraw wrote: > > I find the physical position of my head and ears related to the position > > of the two speakers can produce a null in the sound, especially with a > > tone. > > Because it's a single tone, this is the same phenomena that causes what > we call "selective fading" on the AM band and picket fencing at VHF-UHF. > It's all about the travel time from the two speakers to our ears; if > we're dead center between them, the wavefronts from the two speakers add > because they're precisely in phase (zero degrees difference); as we move > closer to one than the other, the phase difference (measured in degrees) > increases and the don't add as perfectly and eventually begin cancelling > each other; when that difference reaches 180 degrees, they cancel > perfectly. > > At radio frequencies, the fading between peaks and cancellations occurs > because we're receiving the signal over different paths, thus with > different travel times. The difference in speed at which the signal > peaks and dips between what happens at the AM BC frequencies and the > much higher VHF/UHF frequencies is wavelength. > > In the world of pro audio, we were forced to learn the difference > between phase (a continuously valued function that varies both with > frequency and time) and POLARITY, which is REVERSING the signal, like > reversing a pair of wires carrying the signal, or running it through an > inverting gain stage. In the world of audio, the "signal" is not only > one frequency/wavelength, but thousands of them. So the cancellation or > addition varies from one note to the next. If were to plot that on a > graph, it would look like a comb pointing upward, and it can impart a > certain un-natural-ness to the sound. > > 73, Jim K9YC > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] > -- Pete Lascell Forest, VA ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
