Needed: Phase Converter Box

[T. G.]

To the Group:

I am looking for a 180 degree phase converter unit that I can plug a
microphone into and output to an amplifier for noise-cancelling
purposes. (Thanks in advance.)

T.G.

 

[Walter Harley]

"T. G." <NobodysLabRat@webtv.net> wrote in message
news:6265-3F551DD3-137@storefull-2294.public.lawson.webtv.net...

To the Group:

I am looking for a 180 degree phase converter unit that I can plug a
microphone into and output to an amplifier for noise-cancelling
purposes. (Thanks in advance.)

Balanced or unbalanced mic? If balanced, it's just a matter of swapping
pins 2 and 3; you can get ready-built XLR adapters that do this, for about
$25, from suppliers such as Markertek. If unbalanced, a bit more work
involved.

Or, you could just reverse the speaker wires.

Note that depending on what you're trying to do, it is unlikely to work:
sound travels at about 1msec/foot in air, so unless your mic is right next
to your loudspeaker you get comb filtering rather than actual rejection, and
you'll actually get boost at some frequencies.