"Richard Clark" wrote in message
...
On Mon, 15 Nov 2010 17:56:16 -0600, "amdx" wrote:

I can only go by what I have read on the crystal radio groups and they
say 1pw
is audable with very sensitive headphones..

Hi Mike,

You should consider their being very good at this then. 1 pW is the
lowest limit of hearing at 1KHz. No speaker/transducer is 100%
efficient. So, automatically, this claim you have read is suspect in
the highest degree.


Hi Richard,
What do you think of this guys numbers and methodology?
He says he can hear .0078 pw with a Adastra Model: 952-207
http://www.crystal-radio.eu/enluidsprekertest.htm
MikeK


73's
Richard Clark, KB7QHC