Using a Shure Lyric 8700 as an external mic for a smartphone

Discussion in 'The Projects Forum' started by jean.the.beginner, May 29, 2016.

  1. jean.the.beginner

    Thread Starter New Member

    May 29, 2016
    Hello there, i need some help.
    i don't know much about microphones neither impedance and stuff

    I'd like to connect a Shure Lyric 8700 Microphone to my Sony experia
    so far i connected it to my computer through my 3.5 audio imput jack and recorded some tests on Audacity.

    i can see that the microphone is working but the audio levels are very low
    and if i turn the volume up i can notice a lot of background noise

    sounds like white noise

    i suppose its about the impedance

    after some google i found that the Shure Lyric 8700 has the impedance of 600 Ohms

    what should i do in order to have better audio levels when connecting it to my computer
    (and later to my mobilephone?)?


    once i soldered an electret mic to a TRRS plug in oder to use my mobilephone as an external mic recorder
    it worked nice.

    attached i upload a picture of the microphone i want to connect to my mobilephone
  2. Kermit2

    AAC Fanatic!

    Feb 5, 2010
    Your sound card audio input does not have enough gain for the proper response to the small signal of the mic.
    If you connect it to a mic input the gain will be much higher and the SIGNAL TO NOISE RATIO (Google that term) will be correct, meaning you will not here the static type noise while listening to the microphone audio.
  3. KJ6EAD

    Senior Member

    Apr 30, 2011
    The Shure microphone is a completely different type (dynamic) than those intended for use with your phone (electret). You're right about the impedance difference (600Ω vs 1200Ω). That's part of the problem, but additionally, the electret is phantom powered from the phone and has an inbuilt JFET amplifier so it's signal is much stronger than that from your passive dynamic microphone. You need a microphone pre-amplifier made for a 600Ω input.