On Mon, 26 Feb 2007 23:22:42 GMT, "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.

Just to clear the air, can you confirm that the 2k mic was an electret and not a
dynamic? From my experience (commercial communications, not studio) the results
you are getting would be explained by the 2k being a dynamic and the electret
NOT being powered. BTW, I haven't seen a PC sound card that does power a mic.