microphone won't work

My iMac won't take a microphone in on the audio in jack. When i plug it in with the sound panel up in preferences it spikes a little on the plug in (probably feed back), but it won't register a mic. It uses my internal mic. Is this common? i noticed it's call an audio in jack not a mic input. Do I have to use a USB mic, or is my mic input broken?

Again, I don't know how to quote outside of a particular thread, but TenderSurrender offered this advice when someone wanted to have input from a guitar.

"go to the preferences for garage band (top left hand corner click garage band then preferenecs) and in there, is the settings which choose the input."

Also be careful about audio levels. You were right on point when you noted that it is an audio in, not a mic in. There difference is signal levels. If you literally yell into your microphone, you will see the volume meter move ... a little, but not much. The signal strength is too low.

To overcome this, since Macs don't seem to have a Mic In jack, you need to get an external connection. The iMic, which essentially is a USB connected audio hub, seems quite well regarded in this space. See:

http://www.griffintechnology.com/products/imic

I had this problem when I first got my Mac too - had me baffled for quite a while! Good luck!

I just got my iMic a week ago and it works fine. Solved my problem.

I think I'm just gonna return my mic and get a USB mic