Audacity/iMac help

I want to rip audio from youtube using audacity. I know how to do that much, but I have an Intel iMac with the camera and microphone, so when I record, it gets what the microphone picks up, and records it, so it sounda muffled and grainy. Is there any way to record it like it would on windows, which would be what the sound sounds like from the source.

Thanks,
Seamus

I have a macbook, with camera and microphone, so I would like to do this too...............

Audio Hijack (Pro) from Rogue Amoeba Software.

Also WireTap from Ambrosia.

There's an app called PodTube for Mac which actually downloads the movie from youTube and converts it to a Quicktime file, i highly recommend it. Trouble is it used to be free but now you can only get a demo, so try and find the earlier version on Google which is still free, its about somewhere.

Thanks, but what I wanted was a fix that would record what the sound card is getting, not the mic. Thanks for your help though.

The apps I suggest above will do this.