[CW] How do I get high-frequency cutoff from stereo headphones?

[googlyelmo@earthlink.net]

I want to cut the high-frequency response of a pair of mid-quality
closed-cup stereo headphones I use for CW operating.  I'd like to reduce

the 'phones response above 8 KHz or so. I have used in the past true
"communications" grade headphones with response cutting sharply off in
the 7-10 KHz range, so I know what a tremendous benefit they can be for
extended operating compared with phones made for listening to music with

an 18-22 KHz upper cutoff. Much of the QRN, especially on 20 meters and
above, seems to be above 8 KHz. Getting rid of it is like dropping the
weight of
a backpack on an uphill hike.

I remember, dimly, reading somewhere that you can cut hi-freq. response
by adding a capacitor across the two headphone leads.  Am I correct in
my recollection?  If so, does the *type* of cap matter [i.e. ceramic,
mylar, mica, etc.]?  While I know that a bit of trial-and-error
substitution probably will be involved here, what general value should I

be looking at trying?  Finally, exactly how should the cap be wired into

the 'phone circuit?  I think I remember reading that you simply solder
one cap lead to each of the two phone wires, but please confirm/correct
this.  Thanks.

--
Will, KD7BFX
Seattle WA US
King County, Grid CN87tq
ITU Zone 6, CQ Zone 3
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"The wireless telegraph is not difficult to understand.
The ordinary telegraph is like a very long cat.
You pull the tail in New York, and it meows in Los Angeles.
The wireless is the same, only without the cat."
                                                      - Albert Einstein
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