For the Amateur Service with its variations in modulation specifications, it doesn't make any sense to me to put response shaping in the headphones, as we then might want multiple sets for multiple modes. Also, it doesn't make sense to limit the bandwidth at a point where it doesn't affect AGC sensing. Many years ago when it was hard to come by good selectivity at the IF, some bandwidth limitation in the headphones may have been justified for reasons of economical implementation. I don't know if airplane pilots' headsets limit frequency response, but if they do, I suspect it is a matter of standards being hard to change, and manufacturers not wanting cheaper products made for other purposes to work well.
Anyway, I went to RS and bought a pair of MDR-J10 for about $15. These have hooks that go around the ears to hold them securely. I checked them in the store against my old Optimus, and they were about the same loudness on just the hiss from the KX1. Another brand which also had hooks was clearly inferior. Most other types in the store had printed impedance and sensitivity spec's, and were judged inferior based on the spec's alone. 73, Erik K7TV ----- Original Message ----- From: "Don Wilhelm" <w3...@embarqmail.com> To: <elecraft@mailman.qth.net> Sent: Saturday, August 22, 2009 8:39 PM Subject: Re: [Elecraft] KX1 headphones > Wes, > > I agree with you completely. The headphone response should not be the > limiting factor. - headphones should be designed for fidelity, not a > constrained response. > > If the audio response must be tailored, it should be done before the > headphones - the RX response or though the use of an AF low pass filter. > > Some may disagree, but I believe good high fidelity response in the > headphones is important. If the response is not right, the place to fix > it is in whatever is before the headphones. > > I do accept that 'communications headphones' will do the job, but they > are usually an effective low pass filter in combination with a full > range set of headphone transducers. > > 73, > Don W3FPR > ______________________________________________________________ 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
