Macbook Pro Audio Input Not Working With Microphone I am trying to connect microphone to my early 2011 17" MacBook Pro, but I cant get it working. MBP 17" has 2 audio jacks so I supposed the second one is for microphone but just doesnt work (Mac or Windows) and I gotta use USB audio card shipped with my headset.

Am I doing something wrong or the other jack is not supposed for audio input with classic 3.5mm microphone jack?

EDIT:
I of course selected the Line-In device in preferences. The bar under device list wasn`t doing anything while I was talking, but when I was moving with the cable it blinked (I guess because I created some noise by moving the cable).
Mac laptops have not supported a non-powered microphone input for years.
The input you see is a "line-in" input that requires more input signal level than a passive (non-powered) microphone can deliver. 

You will need an additional pre-amp or active mic (a microphone with phantom power will suffice).