Use a speaker as a microphone while useing it as a speaker

[eurobuskers]

if the circuit between the 2 speakers (that is one for each person communicating) is switching between transmitting and recei  8)ving at a very high speed (10k for example) the problem could reduced assuming we know the distance between the 2 people?

 

[audioguru2]

If the speakers and/or microphones at each end were in rooms without any echoes and the speakers don't have any resonances, then switching back and forth at a high audio frequency will stop acoustic feedback howling.
But in our world, rooms and speakers have echoes and resonances.
Distance adds delay which also must be cancelled.
An acoustic echo canceller circuit is perfect for the job of eliminating howling and allowing each person to speak at the same time (full-duplex).

 

[gogo2520]

Hello
      Interesting read. I was wondering what are Q1 and ic1 in audioguru circuit
                                      thanks you
                                        gogo

 

[audioguru2]

I was wondering what are Q1 and ic1 in audioguru circuit

Q1 can be any little NPN transistor.
The project uses a little bridged amp IC but an LM386 amp would work fine (different pinout).
The project is here: http://www.redcircuits.com/Page78.htm

 

[gogo2520]

Thank You
      audioguru
       
            gogo