I concur 100% with Brett (for a change). Filtering should be done electronically where it can be controlled, not mechanically where all it does is add distortion.
It was a revelation when I was first working EME in the early eighties and was still using some military "communications" headphones and I changed over to some Koss "hi-fi" phones and an in-line 200 Hz wide LC filter. There were signals buried in that mush that was all I was hearing with the "communications" phones. Later I bought into the brand "H" hype and got a headset at my local ham emporium. After about five minutes of listening, I took them back. They were simply awful! I don't think much of the microphones either, even though they are wildly popular. It's hard to beat a nice passive LC brute force filter. They can clean up a multitude of sins that we are presented with by the afterthought audio stages in modern transceivers. Wes N7WS --- On Sat, 8/22/09, Brett Howard <[email protected]> wrote: > From: Brett Howard <[email protected]> > Subject: Re: [Elecraft] KX1 headphones > To: > Cc: [email protected] > Date: Saturday, August 22, 2009, 7:05 PM > The filtering should be done before > the audio gets to the headphones. > A low end pair of headphones only acts to cover up flaws in > receiver > design. A good broadband pair of uncolored headphones > should be good > for reproducing audio as it was intended to be done > so. While some > audio reproduction systems are designed to be colored they > are by > nature much less versatile and have narrower usage cases. > > ~BTH > > > On Sat, Aug 22, 2009 at 5:53 PM, Mike Morrow<[email protected]> > wrote: > >>I would not have spent the money on my Etymotics > just for listening to > >>CW, but since they are great for listening to music > with great fidelity > >>while traveling on planes, which is something I do > a lot of, I look at it > >>as a bonus that they will be nice to use in > conjunction with my KX-1 > >>once I build it. > > > > The absolute worst thing one can have in a speaker or > headphones for > > communications use is "high fidelity" and broad > frequency response!!! > > > > Communications-quality audio devices are deliberately > *designed* for limited > > frequency response (typically about 300 to 3000 Hz). > Anything of higher > > "fidelity" is adverse to quality in a communications > device. > > > > One might as well eliminate receiver IF and front-end > filtering if high > > fidelity is the goal. But, of course, high fidelity > is not the goal. Just as > > receiver IFs with limited bandpass are desirable, > especially for CW > > communications, so are headphones with narrow > frequency response. > > Narrow frequency response helps eliminate undesired > signals as surely > > as that IF filter. And since the front-end and IF > filtering in the KX-1 is > > limited, hi-fi entertainment headsets are the last > thing one needs. > > > > QRP rig designers usually provide a headphone jack > that accepts the common > > entertainment-quality headphones with stereo > connections. That seems to > > encourage the use of these unsatisfactory > entertainment audio devices, > > whether they be $5 Walmart specials or much worse, > those wildly overpriced > > "specialty" hi-fi headsets. > > > > The best earbuds for communications use that I've ever > found are Kenwood > > HS-7 mono earbuds, with the essential limited > frequency response. > > Unfortunately they haven't been available for more > than a decade. > > > > If you have headsets that are spec'd for entertainment > audio purposes, that > > should immediately be a warning that they are far from > optimal for communications > > use unless nothing else is available. > > > > Mike / KK5F > > ______________________________________________________________ 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
