[doctorhandshake]

I like this writeup but I feel like the title doesn't really tell you what it's about ... to me it's about creativity within constraints.

The author finds, as many do, that naive or first-approximation approaches fail within certain constraints and that more complex methods are necessary to achieve simplicity. He finds, as I have, that perceptual and spectral domains are a better space to work in for things that are perceptual and spectral than in the raw data.

What I don't see him get to (might be the next blog post, IDK), is getting into constraints in the use of color - everything is in 'rainbow town' as we say, and it's there that things get chewy.

I'm personally not a fan of emissive green LED light in social spaces. I think it looks terrible and makes people look terrible. Just a personal thing, but putting it into practice with these sorts of systems is challenging as it results in spectral discontinuities and immediately requires the use of more sophisticated color systems.

I'm also about maximum restraint in these systems - if they have flashy tricks, I feel they should do them very very rarely and instead have durational and/or stochastic behavior that keeps a lot in reserve and rewards closer inspection.

I put all this stuff into practice in a permanent audio-reactive LED installation at a food hall/ nightclub in Boulder: https://hardwork.party/rosetta-hall-2019/

[scottlawson]

I didn't go into much detail about it but there's a whole rabbit hole of color theory and color models. For example, the spectrum effect assigns different colors to different frequency bins, but also adjusts the assignment over time to avoid a static looking effect. It does this by rotating a "color angle" kind of like the HSL model.

I really like your LED installation in Rosetta Hall, it looks beautiful!

[doctorhandshake]

Thanks! Great article - would like to read one about the color rabbit hole pls ;)

[PaulHoule]

Yeah, "diabolical" overstates it. It isn't a wicked problem

https://en.wikipedia.org/wiki/Wicked_problem

Kinda funny but I am a fan of green LED light to supplement natural light on hot summer days. I can feel the radiant heat from LED lights on my bare skin and since the human eye is most sensitive to green light I feel the most comfortable with my LED strip set to (0,255,0)

[scottlawson]

I'd actually argue it has some wicked problem characteristics. The input space is enormous (all possible audio), perception is subjective and nonlinear, and there's no objective function to optimize against, only "does this feel right?". Every solution you try reframes what "good" means. It's not as hard as social planning but is way harder than it sounds, no pun intended.

[PaulHoule]

Ever seen https://www.youtube.com/watch?v=oNyXYPhnUIs ? There are a lot of things people might think feels right.

(Note both the scanner in front of KITT and the visual FX on his dashboard when he speaks, which changes from season to season.)

[fragmede]

fta: The biggest unsolved problem is making it work well on all kinds of music.

The wickedness comes from wanting something that works just as well for John Summit as the Grateful Dead as Mozart and Bad Bunny.

But it seems like you could cheat for installations where the type of music is known and go from there. The other cheat is to have a "tap" button, and to pull that data and go from there.

mental note: the thought "it can't be that hard" when obviously it is sent me down a rabbit hole for a couple of hours

[jcelerier]

isn't it the exact same problem than "making a good movie" or "making a good book" ? this is just thoroughly subjective.

When the author says:

> Every commercial audio reactive LED strip I've seen does this badly. They use simple volume detection or naive FFTs and call it a day. They don't model human perception on either side, which is why they all look the same.

well no, if they sell, then they are doing just fine until someone comes up with the $next $thing

[ogurechny]

Fidget spinners also sell.

[jcelerier]

.. anything wrong with them?

[diydsp]

I believe it's not a "problem." It's expression, like a painting. Every work of audio reactive LEDs is a reflection of the designer's intent, constraints, biases, imagination, and the context in which it was designed. Like painting, there are technical chops, the craft, like the first half of the article, the lag, the mapping of frequency and amplitude, etc. But once those are mastered the road becomes wide open. That's the "what makes someone tap their foot?" the article asks.