Capturing streaming audio

I tried capturing the audio with iMovie's 'record voice' feature under 'sounds' while playing the streaming audio quite loudly and pointing the mic towards one of the speakers - shabby quality, but recognizable to say the least, and I ran into an error after about 15 seconds of recording (guess some part of my system couldn't keep up the pace) and that's all I got.

I'd be curious to see if anyone else got better results...