- [Narrator] Did you know that a simple speaker
completely transformed modern music festivals,
affecting everything from sound quality, festival layout,
and stage design?
- When I first heard vertical line array,
I knew as soon as I heard it that
that was the way of the future.
[intense music]
- [Narrator] This is Dave.
He's a sound engineer and sound system designer who's worked
on festivals before and after this change
and has provided audio for Coachella since 2001.
How did this speaker affect audio quality?
Ideally, you'd only want one speaker to cover an area,
but for concerts you need multiple.
- What do we do when you have
more than one speaker covering an area?
There's two different basic theories
or concepts on ways to do that.
One is point source.
- [Narrator] With point source,
each speaker acts independently,
creating multiple sound waves that hit the audience
at different times like a firework
or shower head configuration.
This creates inconsistent sound,
meaning you'd hear the music very differently
if you stand here versus here.
So, how do we fix that?
- With a line array, we have a speaker and instead
of putting one alongside of it, we put another one
above it, and below it, and above it, and above it.
Now, as you walk across the horizontal domain,
walk across side to side, you only hear one speaker.
If you were to go up and down, you would hear the problems,
but line arrays pile all the problems up
while we hear them least.
- [Narrator] So, what does it sound like
if you were to walk across a field
with a point source speaker versus a line array?
[speaker hissing]
What we're hearing is called a comb filtering effect,
when interference causes the same sound to be heard
with a very small time delay between signals.
This is the type
of audio interference we'd hear in a point source system
- Fairly beamy sounding, kind of hotspot in the middle
and fades on the left and fades on the right.
What if we take that same thing?
We configure them into a line?
[speaker hissing]
But look what happens vertically.
That's what line arrays do.
They allow you to walk side
by side and have a very smooth sound
very similar to a single driver
because in the horizontal domain, should we slice it,
that's all we have.
- [Narrator] Line arrays made sound clear
and more evenly spread
so that almost anywhere you stand, the show sounds similar.
- First concert I heard it, it sounded
like the PA was closer than it physically looked.
It was kind of messing with my mind.
It was how can it sound so close and look so far?
I'd never heard anything like that before.
- [Narrator] How did line arrays
help create today's festival layout?
- If we have multiple stages on a festival ground,
one of the big challenges is preventing sound
from this stage from affecting this stage.
- [Narrator] With the use of laser range finders,
3D mapping, and precise angling,
sound designers can not only make sure music
from neighboring stages don't bleed into one another,
but that there are no dead zones
throughout the festival grounds.
That means that wherever you stand
you're still able to hear music.
- We used to walk into arenas
and just draw a bunch of Xs, like, oh, put a motor there,
put a motor there, put a motor there, put a motor there,
and fly 'em up to 40 feet.
And that should do it.
It was all eyeballed.
When line arrays were released,
acoustics release software that allowed you to determine
down to a fraction of a degree, the angle between the boxes.
We can now aim sound to a certain distance
and then have it taper off relatively quickly.
We've gained the ability to really cover specific areas.
- [Narrator] We showed Dave images
from past festivals to see how much they've changed.
- Here, if you look at this, behind these rainbow scrims
there is 90 boxes per side.
Each of those boxes is four foot high by four foot wide.
That's huge and heavy.
Takes a long time to set up.
Fast forward, here's Coachella 2011,
also doing a big field gig, and we've gone
from 90 speakers aside to these tall, slender, line arrays.
This was 2001, the first year that we did it.
And here we can see the rat trap rigs.
A system I designed that is four deep,
six wide, kind of an old school system
before the true line arrays came into play.
So, this is when we bought our first Vidos rig
and there is the line array.
So this is, the festival's grown
and you can see that there's less PA, or seemingly less PA,
yet the volume and coverage was actually louder.
Now this one here, we've actually, it looks bigger.
It's actually two line arrays side by side
and that's my fault.
Line arrays should never be put side by side.
They interfere with each other, but I solved it
by not running the same signal into both.
I actually have two PAs here, one for vocals and drums,
and another one for guitar and bass.
They were completely separate
and that was absolutely amazing.
And here is the first year we got the new system.
This is a K1 system
so now we could hang 24 boxes deep instead of 14.
This was the largest deployment
of this sound system that had ever existed
in the world to date.
Look at the change in this year from those drops
and then video screen behind to video screen.
That's Guns N' Roses.
Look at that.
Now here, what they've done is they've taken
that sharp edge outta the screen and made it smooth.
And that's all high resolution video all the way across.
If you really think about it, we wanna hear sound,
we don't wanna see it.
If we could make the sound system invisible,
we will have won.
We want to just hear it.
And line arrays have helped us get a heck
of a lot closer to that.