"Dave Plowman (News)" wrote in message
...
In article 6ZJEh.8700$tA1.2257@trndny02,
Spin wrote:
The electret element in question is 400 ohms imp & it was plugged into
the input of a 600 ohm imp computer sound card. Recording my speech i
noticed that it lacked "highs". I then replaced the above with a 2k ohm
imp element & there was a vast improvement. The improvement consisted
of a higher freq response & a dramatic increase in output (volume).
What baffles me is, i thought that by matching the mic & sound card
with similar impedance that i would get better efficiency? It appears
that my computer sound card (600 ohm input ) works better with a 2k
ohm mic than a 400 ohm mic! By the way the sound card provided the
power for both mics. Any comments concerning the above would be
appreciated.

A nominal 600 ohm input won't be 600 ohms but somewhat higher. At one
time, about 1.2k was the norm for a nominal 600 ohm mic. Which are usually
about 300 ohms. ;-) A higher input impedance shouldn't effect frequency
response but might make the noise figures worse. However, too low an input
impedance will result in a bass loss. Which might sound like a treble
gain.

--
I agree with what Dave says, and would bow to his superior knowledge of
studio audio anyway. Even given the levels of impedance mismatch that you
think you have, and the somewhat worse ones that Dave says you likely *do*
have, it still doesn't seem to me to be a sufficiently badly matched system
to have a such an (apparently) large difference between the two mics. It
might in the end just be "one of those things" that has no rhyme or reason
to it. The sound card might simply just not like the original mic.

Arfa