Fixing iMic Hum Problems

I’m trying to craft up a little podcasting rig here in the office, something better than using the built-in microphone on my iMac. I’ve had a Griffin iMic hanging around, and I bought a Omnidirectional Tie Clip Microphone from Radio Shack this afternoon.

Doing some testing with the iMic and the new microphone, using both Audacity and Sound Studio, there was a noticeable background hum with everything I recorded.

I tried a different Mac, and a different microphone, but the hum remained. Then I stumbled across the helpful Fixing white noise and 60Hz hum when using an iMic and Final Vinyl, which advises, in part:

  • Flip the switch towards speaker. This will amplify the signal coming in.
  • Go to Applications-→Utilites and run Audio MIDI Setup. Set the “Properties For:” to iMic USB Audio System and make sure that both input and output are set to 16bit 44100Hz 2 channels. Most likely it is set to 8bit.

I have no idea what this actually does, but it worked, as you can hear clearly if you listen to the attached MP3 file.


Cameron's picture
Cameron on June 24, 2005 - 13:29 Permalink

I’m having “hum” problems with my iMic. I’m using OSX 10.15 (yea, yea, it’s old, I know) and the audio sound very muddy. The recording, on an MD, is clear. I’m feeding from a Sony MD > iMic > laptop. I’ve returned one iMic, but just found the second one to be as crappy as the first. Any suggestions?

John Comeskey's picture
John Comeskey on May 31, 2011 - 05:41 Permalink

I solved the hum simply by changing USB ports. The one closest to the iMac power cable connection (magnetized) caused the hum. Moved to the next one (farther away from the power cable) and the problem went away.