Tony Andrews paper

Posts transfered from the old forum

jsg wrote:
Hi

As mentioned on the other forum, Mr Andrews of Function 1 fame has popped his head over the parapit, with the following dissertation: www.funktion-one.com/dl/files/1637.pdf

I disagree with some of Mr Andrews' comments. Can you guess which ones?

Deadbeat wrote: Yes, I think I can guess. I think a lot of us do as well.

Tony.A.S.S. wrote: It's no surprise that Mr Andrews knocks the line array and puts forward his own case. For him it's the right thing to do. I was never sure whether the development of F1 was bad timing or intentional. Most of us will see the evolution from Turbo to F1. Although, to a small degree, they were competitors, I actually loved the look of his new system from the first time I saw it. I'm from the old school so I still get excited with impressive things, and the look of F1 was certainly that.
Tony will always be miffed that his bold efforts have been sidelined in favor of line array, especially when you consider how the PA market went for TMS 3's etc., and then of course Flash and Flood.
The lack of interest, I guess, is why F1 got directed towards the dance scene.
Regarding his comments about line array. I would agree with all he has said. When designing a new system, my way was to develop the box, and when it's time for a new one, it had to be better than the last. My biggest problem was that considering the compromised shape and size of line array, how was I going to come up with something I knew was going to sound better box for box than our MX600 for instance. It was never going to happen. So I put aside all thoughts of line array.( this is not to say that someone else couldn't do it, but I couldn't).
When I see how hit and miss they can be, I'm glad I didn't spend fortunes on it. I guess my learned colleague may feel the same.

chaudio wrote: Regarding his comments of time alignment issues in a line array. Don't you get exactly the same issues when you start arraying FK1 boxes vertically? Only maybe worse because of the inter-driver spacing being larger?

csg wrote:
I guess mr andrews would maintain that you can only hear one box at a time in a correctly hung array - however im yet to hear a point source system with no destructive or constructive interference at all

Whilst Tony is entitled to stick to his guns, from my viewpoint funktion one and its product line seems to be rather stuck in a bit of a rutt - fundamentally the ideas and format have not really changed scince turbosound's earliest products from what i can tell
I think funktion one would do well to look at other ways of doing things. since the licencing of functon one designs lapsed at turbosound, and they chose to develop new product lines, i think the product that turbo offers has moved on considerably - Aspect for instance impresses me greatly.
Whilst sticking to ones guns is admirable, i think you have to accept that sometimes the bulk of engineers might be on to something, and that modern sound re-enforcement in the profesional sector has more to deliver than just the best sound quality ( lower rigging costs, quicker rig / derig times, more predictable rig performance, lower trucking costs all spring to mind)
Purest approches are perhaps more suited to the high end hifi scene where individual factors which affect system performance may be more easily and effectively controlled.

I have to say though that a nice cluster of F1 does look rather nice though...

Tony.A.S.S. wrote: CSG, you're dead right about the other aspects of rigs and rigging. It's easy to see why promoters would want line array, considering rigging time and sight lines etc. But the disappointing thing for me is that the accountants and promoters are less concerned about sound than they are about the money. I have always looked for a sound that stimulates and excites me. I know that we should always look forward, but you can only compare with the past. My few experiences with line array have been poor to average, and I have seen great artists where the sound has spoilt my overall enjoyment. So consequently, I remember the days when I would be blown off my feet with ground stacks at various theatres around the country. Especially with someone like Colin Norfield at FOH.

chaudio wrote: If you use line arrays as they are intended, to cover large areas, particularly outside then they can be incredibly effective. Assuming a long, straight array (as they should be used), as you move away from the array, the differences in path lengths to the individual boxes becomes insignificant and the array is behaving as a line source.

I've walked backwards quarter of a mile from a 16 box/side Vdosc array and it still sounded good. I'd like to see a point source system achieve that.

Line arrays get a bad name probably from people using them in short, curved arrays in venues which are too small. Just like with horn loaded systems, you need to be far enough back that you're listening to the array as a whole, not individual boxes.

mykey wrote:

chaudio wrote: Regarding his comments of time alignment issues in a line array. Don't you get exactly the same issues when you start arraying FK1 boxes vertically? Only maybe worse because of the inter-driver spacing being larger?

AJW wrote: I have heard some stunning sounds from LA's in the last couple of years but strangely enough when they are not long enough to act as a true LA, usually just 2 or 4 mid-tops over the bass bins.

I think Tony Andrews is unfortunately "peeing into a very strong wind" though.

Tony

Tony.A.S.S. wrote: I agree, Tony is definitely holding up his hands against the incoming tide, which is a shame because he is fighting a fashion and a trend, and not an obviously better sounding box. My own opinion of line array is as stated before, been based on the average sound being heard with some of favorite bands. There are some people who will agree that a line array system should not be used indoors. My own observations are that the columns are to near the left and right hand walls, which works for a narrow long through system, but not with a wide angle system.
Moving on to the comments about small setups. I saw Deep Purple at the Cliffs Pavilion here in Southend sometime ago. It was EAW and was bass cabs with 4 horizontal cabs above per side. The sound was rubbish, and I was standing where I think is the optimum place, in front of the desk. I constantly looked back to the engineer thinking he might be struggling with something, but he, along with the others were sitting back, which made me think that this sounded normal to them.
Is it anybody else's opinion that LA's can be hit and miss and are more prone to needing a highly concentrated ideal condition to work in, or do my ears deceive me.

Deadbeat wrote:

AJW wrote: I have heard some stunning sounds from LA's in the last couple of years but strangely enough when they are not long enough to act as a true LA, usually just 2 or 4 mid-tops over the bass bins.I think Tony Andrews is unfortunately "peeing into a very strong wind" though.Tony

Then they're just nice speakers...

ajw wrote:
Totally agree, it was the quality of the drivers that shone through.

Tony

jsg wrote:

Deadbeat wrote:

AJW wrote: I have heard some stunning sounds from LA's in the last couple of years but strangely enough when they are not long enough to act as a true LA, usually just 2 or 4 mid-tops over the bass bins.I think Tony Andrews is unfortunately "peeing into a very strong wind" though.Tony

Then they're just nice speakers...

Even if you hang a line array with only 2 cabs, what you have done is to allow the tweeters to "merge" into a single, nearly un-interrupted source. If you hang 2 "conventional" speakers, the tweets are two distinct sources probably over a foot apart. The two tweets cannot have a perfect angualar cutoff (Rayleigh criterion), so must overlap partially and will multipath in the overlap area.

I'm arguing that there is a significant difference even when the line "array" is too short to be a line source at most frequencies.

Of course, a good theory can be implemented badly. A good speaker can be set up badly, and a good setup can still have rubbish music fed into it.

The F1 cabinet styling seems to be deliberately chosen to create a fashion trend in its own right. So F1 have no right to complain if another kind of speaker benefits from being fashionable.

Finally, I'll mention (as I'm sure many of us already know) that humans use more than just phasing to detect the direction of a sound. We use amplitude and frequency response too (the outer ear being a directionally-dependent acoustic filter). So you can't assume that the entire direction-finding capability is down to phase alone.

AJW wrote: jsg, It was the designer of the Coda (BMS) range of speakers that first demonstrated to me the advantages of using LA type boxes even with just 2 per side.
He is as enthusiastic about the merits of LA's as Tony Andrews is about their so called disadvantages.

My own feelings are that a good engineer could probably get the same quality of sound from both given an identical standard of engineering in each system.

From what I hear when listening to both types is that some times the disgraceful sound that we get FOH cannot be explained by the PA alone. I am afraid that in a lot of instances the FOH guy does not appear to understand what is required.
I realise that this comes down to personal choice but surely there is never an argument for the vocals being inaudible* or the kick drum mixed so loud that it totally dominates the sound?

* With the exception of "Girls Aloud" of coarse

Tony

Deadbeat wrote: I know that, John. You've already got a thread on it.

But when you are exceedingly close, I'm saying that the quality of the drivers and setup will matter quite a bit too.

And I reckon that there are better ways you can take advantage of coupling.

But that's another topic isn't it?

jsg wrote:

Deadbeat wrote: I know that, John. You've already got a thread on it.

But when you are exceedingly close, I'm saying that the quality of the drivers and setup will matter quite a bit too.

But wouldn't you design a speaker completely differently anyway, if it had to be listened to up close?

Deadbeat wrote: And I reckon that there are better ways you can take advantage of coupling.

But that's another topic isn't it?

This is my thread and I'll talk about whatever I want

The only thing better than a smooth continuous 1-D source would be a smooth, continuous 2-D source. Like a big electrostatic speaker. Unfourtunately, the rubbish breakdown properties of air limit the forces you can acheive hence SPL. Magnetism would be better since there's no equivialent breakdown problem - but since there's no magnetic monopole, it's harder to build. You end up with somehting like a Heil AMT which doesn't scale up in size so well.

Truly conical sources that are accurate up to 10K+ are hard to build because you run out of space - if you had 4D space you could do it easily, just as a 1D source is easy in 3D space.

Cheers, John

PS AJW my favourites are (1) vocals only audible up to 500Hz so you only get a couple harmonics and (2) lead guitar destroys *everything* else by at least 20dB. And this usually comes after a protracted sound check where they spend 20 minutes making imperceptible tweaks to one snare drum.

jsg wrote:

me wrote: The only thing better than a smooth continuous 1-D source would be a smooth, continuous 2-D source.

In fact I'm not even sure if that's true. Because for a given lower "loss of control" frequency (below which pattern control is lost), the line only has to be a certain length L, wheras a surface source would have to measure on the order of L*L. That's such a big array, you wouldn't be able to see the performers. Unless you could combine the speakers with the big screens, perhaps by using some acoustically transparent LED matrix.

Deadbeat wrote: 'But wouldn't you design a speaker completely differently anyway, if it had to be listened to up close?'

I was under the impression that AJW was listening up close for some reason. Sorry.

If you were listening up close, you would only need a single speaker anyway.

AJW wrote:

Deadbeat wrote: 'But wouldn't you design a speaker completely differently anyway, if it had to be listened to up close?'

I was under the impression that AJW was listening up close for some reason. Sorry.

If you were listening up close, you would only need a single speaker anyway.

No it was actually in a very large Demo hall that they use. We spent a good 30min walking around the hall listening at various positions. I was very impressed with the sound but I still reckon that it was as much to do with the quality of the drivers than the methodology employed.

Tony

Steve_B wrote: If you work on the principle that there is no such thing as bad publicity Mr Andrews has done quite well with this paper.

jsg wrote: OK, but some might consinder his 18uS theory to be jumping the shark

en.wikipedia.org/wiki/Jumping_the_shark

Jazomir wrote: Got to agree on the positioning of the line array. If a box has a (say) 90 degree dispersion angle (at whatever frequency that the manufacturer states this is so), the logical place to put the box is in the front corners of the venue at 45degrees to the front & side walls to give even horizontal distribution - the only disadvantage to this would seem to be the possibility of feedback on stage (this wouldn't be a problem if the beamwidth was actually 90 degrees with sharp, off-axis cut-off). But where do we see all line arrays being placed, yes, that's right, either side of the stage, backs to the wall with loads of side scatter and reflections off the side walls - but, hopefully none of the floor or ceiling due to restricted vertical dispersion.
On the flip side, I have seen several photos of F1 arrays being used outdoors with the top row of cabs firing into the air way above the audience - to what end? I believe that messrs Newsham & Andrews have a theory about wind shear or pressure gradients or something similar (proportional dispersion) that requires the top part of their rigs (HF) not to be pointed down into the audience, possibly in attempt to reduce HF roll-off over distance. Anyone any other ideas?

jsg wrote:
Maybe heavy wind can bend the sound path that much, or maybe there are diffraction effects at the edge of the coverage pattern, or maybe the coverage pattern narrows in the mid-bass range. Whichever of these it is, one could just as easily fire the top cabs of a line array up into the air if requred.

The real trade-off is of unwanted noise pollution off-site. One should compare like with like in terms of systems that meet the same environmental criteria, especially now as creeping neo-totalitarianist nanny-state crypto-fascist clunking fist douchebags are marching in lockstep all over our civil liberties.

Jazomir wrote: I don't believe that wind would affect vertical dispersion to that degree (except in a case of wind shear or down-draft) but it can certainly affect horizontal dispersion big time as anyone who has been at an outdoor event on a windy day can testify to. The effect I was thinking about has an analogue in oceanography - the Gulf Stream is water flowing within water with sharply defined edges when viewed from space - except that the edges are not that well defined but constantly changing producing eddies and swirls and other effects. These eddies are sections of moving water that swirl off from the main Gulf Stream current and loop back on themselves, forming something like whirlpools. They consist of water that is of different temperature than the water that surrounds them. On the surface, eddies are usually about 100–300 km in diameter. However, they are not just surface features. They are cylinders of water that can reach to depths of almost 4000 m. So, in the analogue we have a disturbed flow - possibly the same occurs in sound waves (due to friction or possibly pressure differential) and this effect is why F1 set up their systems in the way that they do.
The other matter, namely sound spill, at frequencies other than at the bass end of the spectrum, is controllable by judicious aiming of the (hopefully well defined) beam from the cab(s). There is a picture on F1's site which shows a setup at London's Kenwood House, a venue which I know well, and it seems to show the top row of the rig firing horizontally over the audience, which is situated on a steeply banked hillside. Now, one of the problems that have plagued this venue is sound spill into the surrounding area whose roads (Hampstead Lane, Bishops Avenue, Compton Avenue, Sheldon Avenue etc) contain some of the the most expensive house in London and also contain some of the most vociferous residents. Consequently, even though the complaints from neighbours are mostly about the accompanying firework displays, noise spillage from concerts is still a major headache and was never really tamed while I was a concert goer there, with strict noise level restrictions both on and off site, and I wonder whether the judicious use of the F1 rigs there has managed to tame the problem - if it has, then the set-up works, but I personally would have my doubts that such a set-up would provide reasonable levels to the audience but stop noise spill.
Temperature inversion, as happened at Glasto in 2007, is an additional problem to contend with and has similar causes and effects. This is Wikipedia's definition: "When on a clear and calm night, a radiation inversion is formed near the ground, the friction does not affect wind above the top of the inversion layer. The change in wind can be 90 degrees in direction and 40 kt in speed."- some effect to have to deal with, isn't it?

Below is a view of the Gulf Stream taken with by thermal imaging satellite. The temperatures are irrelevant - it's the eddies that are important. Do high frequencies from a speaker behave in a similar way with flowing eddies caused by friction - they are low energy, after all? Or is this just the case for viscous liquids?

From my understanding of waves, a temperature inversion (ie air closer to the ground colder than the air above) would cause the sound waves to be refracted towards the ground and actually be helpful????