For me one of the most impressive parts of this article where how they managed to eliminate feedback on the vocal microphones.
They did this by using two microphones, using one of the microphones for the singer, the other for the background noise. By inverting the phase on one of the microphones and then summing these two signals they filtered out the background noise. At least this was my understanding.
Sometimes it's really great how far we have come with technology and what tricks they've used in the past.
@good sound guy:
you're absolutely right - but most of the good and / or big bands have their sound guy anyways.
I always wondered if it still sounded natural, or if there was some kind of comb-filtering to the vocals that just didn't matter due to the style and volume of the music.
I've played with multiple out of phase mics myself (to try and reduce drum bleed from the main vocalist mics) but never found it as effective as I'd hoped.
I think the problem was just how stinking loud the ambient drums just in general were to the room. Maybe outdoors with a bigger rig it would have worked.
Still pretty fun to play with though.
There's so much mad stuff you can do when you start playing with out of phase mics, delay, etc. As a party trick I occasionally pull a mic up to the point of feedback, whistle until I have a stable loop, and then can whistle in harmony with myself.
I think one of the guys in the article says that the sound was not too good. I think I've read the term "comically". Another problem was that it didn't work well if the singer was not singing close to the mic, so the ambient mic direct vocals on it too.
But I think it was a big improvement to what they had before.
IIRC they had the double microphone configuration in The Grateful Dead Movie (it's been a while since I have seen it). If I remember correctly, it sounds a bit different indeed.
It's probably on Youtube, so you can listen and judge yourself ;).
Odds are pretty good that your cellphone uses a similar noise-cancellation system, with a mic on the top sampling the ambient noise to subtract it from the mic by your mouth.
They did this by using two microphones, using one of the microphones for the singer, the other for the background noise. By inverting the phase on one of the microphones and then summing these two signals they filtered out the background noise. At least this was my understanding.
Sometimes it's really great how far we have come with technology and what tricks they've used in the past.
@good sound guy: you're absolutely right - but most of the good and / or big bands have their sound guy anyways.