microphone interfacing

Discussion in 'The Projects Forum' started by jcd, Mar 7, 2011.

  1. jcd

    Thread Starter New Member

    Mar 7, 2010
    i am working on project involving location of sound source.I need to take data from at least 4 microphones ,but computer sound provides only 2 channels.I was wondering if one could send two signals through same channel so i can get 4 signals into computer and then extract the signals.I am using MATLAB to process signals.

    thank you
  2. wayneh


    Sep 9, 2010
    A digital audio port can handle at least 5 channels.

    I don't think you'll ever want to mix the audio channels, thereby losing the very thing you want to measure.
  3. SgtWookie


    Jul 17, 2007
    You could multiplex four channels into two using some circuitry, like perhaps a 4066 quad switch - of course, that means you'd need to use a USB or other interface to control the switch.

    Basically, you'd have four mics facing into a parabolic reflector in a "+" pattern. Switch in the high and low mics (Y-axis) and listen for a few milliseconds, steering the antenna in the Y-axis towards the sound. Then switch to the left and right mics (X-axis) and steer the antenna in the X-axis towards the sound.

    Of course, that's a good bit more complex than using a sound card that has sufficient channels.
  4. bribri


    Feb 20, 2011
    a soundcard with 4 or more input might not be too expensive.

    otherwise you might matrix the sound with some wacky phase-shift encoding like dolby pro-logic or M+S recording.