Hi there! I think I have this sussed.
"There are different audio signal levels that microphones produce; mic level, line level, and professional line level... Most microphones produce mic level output... Mic level is lower then line level, and line level is lower then a professional line level...If a microphone that outputs a mic level is used with [certain Macs] the signal produced from the microphone is too low... However, a mic level microphone could be used if a microphone preamp is used. The microphone preamp boosts the mic level to a line level."
This was from:
http://docs.info.apple.com/article.html?artnum=15884
My mic is a $10 buffalo PC mic. Cheap and cheerful. What's the betting it is a mic level microphone which I surmise is impossible to use directly with MacBooks. It is OK on my Sony Vaio though!
From a review:
"FYI
Written by SM from Dundas
Apr 7, 2008
For all who are complaining about this microphone, the reason it does not just work when plugged into a mac is because the audio input on a Mac is line level (-10dB / +4dB) not mic level (-40dB), nothing to do with digital or analog. To get to line level a preamp is required, for example iMic or any mixing board."
http://store.apple.com/us/product/TH597LL/A?fnode=home/shopmac/mac_accessories/musiccreation&mco=Njg2NzY3#overview
The Apple shop sells USB mics and they are plug-in an record. That's they way to go!
