Geeky Technical Videos/Articles

[JayBalls]

 

[shoptildrop]

1 hour ago, JayBalls said:

 

That's amazing and hats off to the litter pickers there

[JayBalls]

 

[stuartbert two hats]

On 07/04/2017 at 5:20 PM, JayBalls said:

 

That's almost a brilliant video.  All they needed to do was pan much more slowly backstage and not spend most of the time filming the crowd!

[Trout Mask Replica]

Great thread this. 

[JayBalls]

On 06/04/2017 at 11:53 PM, shoptildrop said:

hats off to the litter pickers 

Great to see isn't it

 

 

 

Got milk?

[musky]

On 03/04/2017 at 5:25 PM, stuartbert two hats said:

Is it the software that's the secret sauce here, rather than it being a line vs point thing?  I.e.  could you do something similar with point source rigs, in terms of limiting sound to the arena and getting a uniform sound field?

To an extent, but it's mostly down to the dispersion of a line array.

Line arrays work (in theory) because they produce a cylinder of sound, rather than the theoretical omnidirectional sphere of a point system. When you use a larger diameter speaker the one thing that is absolutely guaranteed to happen is that you'll reduce dispersion. By placing speakers close to each other they act as if they are a larger speaker, but only in that plane, so by creating a stack of speakers that is very tall but narrow you end up with a sound source that is constrained in the vertical plane but has good sideways dispersion. By constraining the sound in this way the areas that fall within the spread of sound will also receive a greater intensity of sound, much like placing a mirror behind a light bulb will make things brighter in front of it while blocking some of the light behind.

Another advantage of the line array is that it's the upper speakers that are pointing directly at the areas furthest away, so that by reducing the level to these you can reduce the volume at the perimeter whilst leaving most of the field unaffected. Meanwhile those in front of the speakers aren't getting blasted simply because the bottom of the speaker columns are curved (which allows greater dispersion and hence less intensity) and use cabs with different characteristics.

The software that really comes into it's own is of the modelling variety which allows you to see exactly the effects of different configurations on the arena, but I'm not aware of anything that will actually cancel the sound at the boundaries. It's the lower frequencies that cause the most issues as they also carry the most power. All you can effectively do is reduce the bass and rely on the inverse square law (doubling the distance from the source decreases power fourfold).

Edited April 9, 2017 by musky

[stuartbert two hats]

37 minutes ago, musky said:

To an extent, but it's mostly down to the dispersion of a line array.

Line arrays work (in theory) because they produce a cylinder of sound, rather than the theoretical omnidirectional sphere of a point system. When you use a larger diameter speaker the one thing that is absolutely guaranteed to happen is that you'll reduce dispersion. By placing speakers close to each other they act as if they are a larger speaker, but only in that plane, so by creating a stack of speakers that is very tall but narrow you end up with a sound source that is constrained in the vertical plane but has good sideways dispersion. By constraining the sound in this way the areas that fall within the spread of sound will also receive a greater intensity of sound, much like placing a mirror behind a light bulb will make things brighter in front of it while blocking some of the light behind.

Another advantage of the line array is that it's the upper speakers that are pointing directly at the areas furthest away, so that by reducing the level to these you can reduce the volume at the perimeter whilst leaving most of the field unaffected. Meanwhile those in front of the speakers aren't getting blasted simply because the bottom of the speaker columns are curved (which allows greater dispersion and hence less intensity) and use cabs with different characteristics.

The software that really comes into it's own is of the modelling variety which allows you to see exactly the effects of different configurations on the arena, but I'm not aware of anything that will actually cancel the sound at the boundaries. It's the lower frequencies that cause the most issues as they also carry the most power. All you can effectively do is reduce the bass and rely on the inverse square law (doubling the distance from the source decreases power fourfold).

Thanks for the reply. I'll respond when I've read it another five times. Fascinating stuff.

[musky]

24 minutes ago, stuartbert two hats said:

Thanks for the reply. I'll respond when I've read it another five times. Fascinating stuff.

I know what you mean.

I've only picked up this stuff as I play the bass, so some understanding of how difficult it is to reproduce bass frequencies and the problems with acoustics is quite useful. Try telling a guitarist that he'd better off ditching a 4x12 or angling his cab upwards though!

[billum]

5 minutes ago, musky said:

Try telling a guitarist that he'd better off ditching a 4x12 or angling his cab upwards though!

Tick, and tick! 1x12, always up off the floor, sounds great. But glad I don't have to face the issues you bass players have... Happy to be keeping it all above 82Hz...

[musky]

8 minutes ago, billum said:

Tick, and tick! 1x12, always up off the floor, sounds great. But glad I don't have to face the issues you bass players have... Happy to be keeping it all above 82Hz...

I must be playing with the wrong guitarists!

[billum]

5 minutes ago, musky said:

I must be playing with the wrong guitarists!

Ha! Speak to my agent... 

[JayBalls]

 

[JayBalls]

Snooker loopy!

 

[ripcurl85]

Am I right in thinking that Steve Davis is playing again this year? Rack 'em up!

[VolumetricFox]

Not sure if this counts, snapshot of the whiteboard in the office from 2013.

https://metrouk2.files.wordpress.com/2013/06/ay112584213glastonbury-engl.jpg

[JayBalls]

 

[Stretlow]

On 5/11/2017 at 4:21 PM, JayBalls said:

Snooker loopy!

 

Worst thing ive ever seen /heard

[musky]

On 30/05/2017 at 8:53 AM, VolumetricFox said:

Not sure if this counts, snapshot of the whiteboard in the office from 2013.

https://metrouk2.files.wordpress.com/2013/06/ay112584213glastonbury-engl.jpg

This hasn't got as much love as it deserved.

Pyramid Ducks? Greenfields ogre? Flushy loos should make at least some people happy (assuming they're going to be public).