When I first got my K3, I wanted a nice pair of speakers so I bought two Tivoli Audio extension speakers from their outlet store. They look and sound nice, although they have gone way up in price lately.
To get the maximum effect from the stereo AFX performance, I placed the speakers several feet apart on a shelf right above the operating desk. The sound was good. But every now and then I would have to scramble to more clearly hear a station at a particular CW tone. Sometimes I would have to plug in the phones to be able to copy the station properly. Then I realized what might be going on. Sound waves travel at a speed of 344 meters per second. Wavelength is speed divided by frequency. So, the wavelength of a 344 Hz tone is one meter. When two sound waves meet, they can either add together (in-phase, or constructive interference) or cancel each other (out-of-phase, or destructive interference). Since I like to listen to lower frequency tones (like 400 Hz), there seems to be some cancellation going on at certain locations where I normally sit, depending on the particular pitch that I am copying. I pressed the “pitch” button and walked around the room while listening to various tone frequencies and I “think” that I can find spots where the sound is attenuated. There are other effects going on like reflections, etc. Maybe it is not a good idea to have the speakers too far away from each other. So, anyway, I will try different locations for the speakers, or drop down to only one speaker and use the AFX with only the headphones. There is nothing wrong with the K3. This is basic physics about the sound waves from two sound sources. It has the biggest effects at CW single-tone lower frequencies, and probably is not that much of a factor with the complicated sound waves in normal speech and music. And, I could be filled with hot air, which is also basic physics hi hi. 73, John W2XS -- View this message in context: http://n2.nabble.com/K3-CW-Sound-Wave-Canceling-tp1586193p1586193.html Sent from the Elecraft mailing list archive at Nabble.com. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
