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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)

#71

Post by hunter2_ »

mrob wrote: post #20
jtriangle wrote: post #13

Dave Rat, of Rat Sound/RHCP/Bassnectar/etc fame, has some very interesting takes on the wall of sound idea using modern equipment. The core of it is that speakers are bad at polyphony, so if you can avoid it, you can produce something that sounds more natural to human ears, and do so in a larger area. The way to avoid it is more speakers, more stacks/arrays/etc. You don't necessarily need an array per instrument, bec…

Another advantage of individual speakers for each instrument is that it allows positioning them without the phase cancellation artifacts you get with a stereo setup. It's obvious with some sounds, e.g. try playing some mono pink noise on stereo speakers and move your head. Then try again after hard panning the audio to only one of the speakers. This is why adding a real physical center channel makes dialogue clearer…

The center channel also helps by allowing the listener to localize the dialogue differently than the music/FX. When the dialogue comes from a different point in space, it doesn't need to be louder than the music/FX for sufficient intelligibility. When downmixed to stereo or mono or any other non-center-having configuration, the dialog must be mixed well above the music/FX to avoid being masked by it. Sometimes a downmix occurs without this step being given enough consideration, resulting in complaints about the mix, when the original 5.1 (or whatever) mix was perfect but an engineer wasn't involved for downmixing.

This is also what Dave Rat is on about, in addition to IM and combing concerns, when explaining why a speaker per instrument sounds better than a mix: not just that it's a single point source, not just that it's doing one single job, but that all the sounds come from discrete points nowhere near each other. Just like an acoustic band using no reinforcement.

Re: The Grateful Dead's Wall of Sound (2019)

#72

Post by dekhn »

owenmarshall wrote: post #60
gjmacd wrote: post #19

The most incredible sound system to hear a band play out of tune and out of key for 90 minutes.

90 minutes? At a _Dead_ concert?! That’s enough to cover a typical Playing>Uncle John’s>Drums>Space, and probably not get all the way through the reprises. You’ve easily got another two hours of jam.

also, they were "in tune" and just playing in a mode, rather than a typical key.

Re: The Grateful Dead's Wall of Sound (2019)

#74

Post by hunter2_ »

jtriangle wrote: post #57
JohnBooty wrote: post #51

Earlier quoted context omitted.

The core of it is that speakers are bad at polyphony You can look at intermodulation measurements for some popular and affordable home speakers here. The TL;DR is yeah, you're going to go from something like -60dB distortion to -40dB when doing synthetic multitone tests, but I would not remotely characterize this as being "bad" at polyphony nor the primary reason for the Wall of Sounds primordial "one vertical speake…

I'm simplifying things significantly because I don't expect most HN'ers to know the ins and outs of pro sound. Dave Rat has a good youtube channel, he also has some sort of insider subscription thing that I've never bothered with. I wouldn't say his ideas necessarily translate to every situation, but, he really presents these ideas as tools to use in a toolbox, not as gospel. One interesting thing is that, we general…

The opposite delays is an interesting touch. Basically steering the "power alley / valleys" (which of course are a gradient of lobes whose actual positions vary by frequency, but when you're in a 60-80Hz valley, you're in a bad spot) of each LF instrument so that instead of being uniform, the one with kick is angled a little left while the one with bass is angled a little right, so any given member of the audience finding themselves in a valley for one is in the alley of the other. And then the chaotic smearing from EQ tweaks makes the valleys even less stark. Hmm! Definitely one of those "it's good if it works" type things, I suppose. #808

Re: The Grateful Dead's Wall of Sound (2019)

#75

Post by [deleted] »

hunter2_ wrote: post #68
plussed_reader wrote: post #14

Earlier quoted context omitted.

Since balanced cables predate the GD, this strikes me as an acoustic implementation of an EE concept. Neat!

The history of balanced lines (common mode rejection, differential pair, etc.) is fascinating. Apparently the first twists (as in "twisted pair" to pick up external interference as similarly as possible on each conductor) were achieved not within a bundled cable, but between utility poles. Every two spans would constitute a full twist, with two single wires alternating from left to right on the cross member. But as f…

[deleted]

Re: The Grateful Dead's Wall of Sound (2019)

#76

Post by [deleted] »

itishappy wrote: post #7
scrumper wrote: post #4

Article 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.

[deleted]

Re: The Grateful Dead's Wall of Sound (2019)

#77

Post by mannyv »

TylerE wrote: post #28
scrumper wrote: post #4

Article 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…

While it's true that they did that and why, I'd ultimately chalk it up as more of a flaw than a feature. Vocals never sounded great on wall of sound shows because they could never sing perfectly into one mic. This can be confirmed by listentng to soundboard tapes of the shows, and comparing them with ones a year or two either side - the full on Wall was only used for about a year. While the WoS laid much of the groun…

"Modern PAs can self-tune the whole system just from playing a short burst of white noise through the system, and listening for the response"

A technology which was developed by/with the Grateful Dead, by the way.

From what I understand they essentially financed the modern PA industry by spending a ridiculous amount of money on sound equipment. People don't realize how much money they made - they were pretty much the top grossing tour band for about 15-20 years, playing about 90-100 shows a year. And they could (and did) use those shows to experiment with sound in a way that probably no other band has done since.

I haven't watched any D&C shows, but I expect their sound quality was just as good, if not better, than the Dead's.

Re: The Grateful Dead's Wall of Sound (2019)

#78

Post by switz »

gverrilla wrote: post #69
switz wrote: post #52

Earlier quoted context omitted.

Hey! I created this website and have been maintaining it along with my friend Alec for the last decade. Fun seeing it pop up here on HN. Thanks for sharing!

Been enjoying the music on your website for the last hour, very grateful for your work! :) Why those bands, and not others? What do they have in common?

All of these bands have agreed to allow people to tape and distribute their concerts for free. This is most popular in the jam band community, but you’ll find a plethora of other bands that allow it as well.

Re: The Grateful Dead's Wall of Sound (2019)

#80

Post by dekhn »

mannyv wrote: post #77
TylerE wrote: post #28

Earlier quoted context omitted.

While it's true that they did that and why, I'd ultimately chalk it up as more of a flaw than a feature. Vocals never sounded great on wall of sound shows because they could never sing perfectly into one mic. This can be confirmed by listentng to soundboard tapes of the shows, and comparing them with ones a year or two either side - the full on Wall was only used for about a year. While the WoS laid much of the groun…

"Modern PAs can self-tune the whole system just from playing a short burst of white noise through the system, and listening for the response" A technology which was developed by/with the Grateful Dead, by the way. From what I understand they essentially financed the modern PA industry by spending a ridiculous amount of money on sound equipment. People don't realize how much money they made - they were pretty much the…

From one of the dead's main sound engineers, Dan Healy, who helped establish this technology (I wasn't able to find any further discussions, but I know I've read a few interviews where he talked about doing this at the soundboard).

"""What tools do modern sound engineers have at their disposal that you didn’t? Computers and all the things that became possible at the advent of computers. It’s removed the limitations to creativity. Nowadays, in terms of concert sound, you can not only correct the sound for any room, you can ongoingly correct it in real time as the room changes and as the temperature changes and as the humidity changes. We used to do that in the ’80s and ’90s – I had a complete weather station at my mix board and we tracked temperature, humidity, barometric pressure, because they change sound dispersion, sound quality. We corrected the systems accordingly. We did long, long studies and mapped it out, and we had curves so we could predict where the sound was going. We had to do that by hand. Nowadays, it happens all by itself."""

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