The Grateful Dead's Wall of Sound (2019)
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The Grateful Dead's Wall of Sound (2019)
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Re: The Grateful Dead's Wall of Sound (2019)
#2I remember chatting with a sound technician at a concert once and he told me that putting amplification in front of the performers only started happening in the late 60's (ish). Before that musicians were actually subjected to insane DB's by standing only a few meters in front of the amplification. (Don't take this is as fact, but this diagram suggests that he was correct)
Re: The Grateful Dead's Wall of Sound (2019)
#3Th' Dead not only allowed taping, they encouraged it: at the shows I attended, there was invariably a small grove of microphones set up near the soundboard, in the middle of the audience.
https://en.wikipedia.org/wiki/Taper_(concert)
(a disadvantage to too much ethology reading: I can't remember "Bill Graham Presents" without thinking of baboon behaviour)
Re: The Grateful Dead's Wall of Sound (2019)
#4Article doesn't mention one of the more interesting (to me) aspects which was how feedback was avoided. The solution is elegant: each vocal microphone is doubled, meaning there are two at each position. The phase is inverted on one of them, the singer sings into only one, and both are sent to the speakers via their channel's amp.
The effect of that setup is that only the difference between the two microphones is amplified; common signal in both (i.e. the sound coming out of the speakers) is nulled out, but the difference signal (the voice) makes it through. It apparently wasn't quite perfect but was absolutely a lot better than wailing feedback.
The thing that made it sound so good was that any given speaker only reproduces a single source, but the article touches on that. The mic arrangement I described is simply what makes it possible.
Re: The Grateful Dead's Wall of Sound (2019)
#5Th' Dead not only allowed taping, they encouraged it: at the shows I attended, there was invariably a small grove of microphones set up near the soundboard, in the middle of the audience. https://en.wikipedia.org/wiki/Taper_(concert) (a disadvantage to too much ethology reading: I can't remember "Bill Graham Presents" without thinking of baboon behaviour)
I'd love to hear more about your experience and observations of taping at the shows.
Not only did GD (and particularly Jerry Garcia and John Perry Barlow) eschew the 'intellectual property' model of music, their thought-leadership has lived on to become much of what we today consider fundamental internet technology and methodology.
Early decentralized crypto-economics, peer-to-peer file sharing, and the founding of the Electronic Frontier Foundation were all developed by some combination of deadheads and musicians and tapers, particularly on an internet service called The WELL.
The Green Pill Podcast had an entire episode exploring the bluegrass roots of blockchain technology; I was humbled / psyched to be a guest and play several of my songs, as well as some traditionals that GD also played. It's here if you're interested: https://www.youtube.com/watch?v=Y3s9Fu4yu7o&t=2898s
Re: The Grateful Dead's Wall of Sound (2019)
#6You can see a partial legacy of the "Wall of Sound" at most concerts today - vertical line array speakers.
https://www.soundonsound.com/techniques/line-arrays-explaine...
For the most part, each performer plugged into the "Wall of Sound" had their own vertical 1xN stack of drivers.
3 drivers in a vertical line away will have less distortion than 3 drivers in a horizontal array; the horizontal drivers will suffer from comb filtering for listeners who are not located dead center at the middle of the array. (This of course assumes your audience is dispersed horizontally as opposed to floating randomly in space)
Modern home loudspeakers hew to this philosophy as well to an extent. As opposed to big "monkey coffin" 70s speakers with a random array of drivers sprayed across the front of the speaker[1], modern tower speakers have a vertical array of 2 or more drivers whose centers are aligned in a vertical line[2].
____
[1] https://www.reddit.com/r/BudgetAudiophile/comments/yburht/at...
[2] https://www.audiosciencereview.com/forum/index.php?threads/r...
Re: The Grateful Dead's Wall of Sound (2019)
#7Article doesn't mention one of the more interesting (to me) aspects which was how feedback was avoided. The solution is elegant: each vocal microphone is doubled, meaning there are two at each position. The phase is inverted on one of them, the singer sings into only one, and both are sent to the speakers via their channel's amp. The effect of that setup is that only the difference between the two microphones is ampl…
> common signal in both (i.e. the sound coming out of the speakers) is nulled out, but the difference signal (the voice) makes it through.
What drives this? Singers and speakers are both localized sources, so I'd expect the mics to pick up similar phases for each.
I bet it's distance! Falloff depends on distance to source, so there should be a larger difference in volume for closer sources.
Re: The Grateful Dead's Wall of Sound (2019)
#8Article doesn't mention one of the more interesting (to me) aspects which was how feedback was avoided. The solution is elegant: each vocal microphone is doubled, meaning there are two at each position. The phase is inverted on one of them, the singer sings into only one, and both are sent to the speakers via their channel's amp. The effect of that setup is that only the difference between the two microphones is ampl…
> common signal in both (i.e. the sound coming out of the speakers) is nulled out, but the difference signal (the voice) makes it through. What drives this? Singers and speakers are both localized sources, so I'd expect the mics to pick up similar phases for each. I bet it's distance! Falloff depends on distance to source, so there should be a larger difference in volume for closer sources.
Yeah one microphone was behind the other, though I was under the impression it was half a wavelength behind and thus created something quite akin to modern active noise-cancellation?
Edit: Apparently this is not the case!
Re: The Grateful Dead's Wall of Sound (2019)
#9[deleted]
Re: The Grateful Dead's Wall of Sound (2019)
#10Article doesn't mention one of the more interesting (to me) aspects which was how feedback was avoided. The solution is elegant: each vocal microphone is doubled, meaning there are two at each position. The phase is inverted on one of them, the singer sings into only one, and both are sent to the speakers via their channel's amp. The effect of that setup is that only the difference between the two microphones is ampl…
> common signal in both (i.e. the sound coming out of the speakers) is nulled out, but the difference signal (the voice) makes it through. What drives this? Singers and speakers are both localized sources, so I'd expect the mics to pick up similar phases for each. I bet it's distance! Falloff depends on distance to source, so there should be a larger difference in volume for closer sources.
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