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Wired clip-on mics mystery

Discussion in 'Microphones' started by sreenadh, Feb 27, 2012.

  1. sreenadh

    sreenadh Active Member

    My apologies if this is a stupid question, or already answered many times -I am not sure what exactly to search for. I have a handheld recorder that came with two wired clip-on microphones, intended for interviews. They work perfectly with the recorder. However, when I plug these microphones into a mixer/amplifer (Behringer PMP5000) they don't work at all. I later purchased some more cheap clip-on mics, and they too have the same problem - work fine in handheld, don't work in "real" audio. Other microphones work fine in both situations (and with the same gain settings on the handheld, I get similar volumes between these mics and the ones that don't work on the mixers), so it does not seem to be a question of output levels.

    What could be the "special feature" of these cheap microphones that cause them not to work with audio mixers ?
     
  2. Boswell

    Boswell Moderator Distinguished Member

    Lapel microphones like this usually need a source of low-voltage power. This is often called "plug-in power" and is in the region of 1.5 - 5V. Do not confuse it with "phantom power", which is the 48V power source used by professional microphones.

    Multi-channel sound mixers can provide phantom power but not plug-in power, and this is likely to be the reason that you are getting no output from the lapel mics. You can get little battery boxes that you insert in the lead between the mic and the mixer, and these will provide the few volts needed for these mics to function. I can't vouch for the function of this, but (Dead Link Removed)
     
  3. sreenadh

    sreenadh Active Member

    That would explain it! Thank you for the tip. I was going to use these lapel microphones for videotaping a group of people (panel discussion). Do you know if there exist mixers designed for this type of application (i.e with switchable 5V power applied to each microphone input) instead of buying separate battery boxes for each line?

    Thanks again

    - Sreenadh
     
  4. Boswell

    Boswell Moderator Distinguished Member

    If you have mono lapel mics, I would just get a single battery box, as these are usually set up for stereo operation. With a suitable splitter adaptor, you can put two mono mics through it and then out to separate channels on the mixer.
     
  5. vttom

    vttom Active Member

    Does the handheld recorder have a line-out? If so, use the recorder as the power-source for the mics, and plug the line-out from it into the mixer.
     
  6. sreenadh

    sreenadh Active Member

    Thanks, yes, that is what I did, when I had just two people talking. Now I want four people to talk, so I purchased a few more cheap lapel microphones to use with my mixer. A mixer with switchable plugin power would be great. I found one with four inputs and one output designed to work off USB power, but with no individual controls for the four lines. Looks like the best way may be to build something myself (found some good info at Powering microphones and Simple Mixer Schematics

    - Sreenadh
     

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