Concert set ups.

[nigelwright7557]

Does anyone know how concert audio systems are configured ?

Is it lots of powered speakers daisy chained ?
Is it lots of very high power amplifiers driving multiple speakers.

I was thinking along the lines of big concerts rather than small ones.

[imix500]

Depends,

If the boxes are self powered then each box has as many as 4 channels of amplification inside. All that is needed is signal distribution, good power distribution, and sometimes data if the boxes support monitoring/control ability.

If the boxes are passive, then most of the time groups of drivers are on each channel of the amplifiers. Some providers like to load each channel down as much as is allowed by the manufacturer, some like to make it easy on the amps and run everything at a lighter load.
Power distribution to the amp racks and amplifier output cabling/distribution becomes an important issue in that case.

[mickeymoose]

Rock&Roll?
Classical?
Country?
Religios?
Audience size?
Venue size?
dB level at the audience?
A 1000 other questions to provide a valid answer.
Books and web-thingies galore, as are snake-oil salesmen

[dmills]

Most of the BIG stuff tends to be flown (so weight in the boxes is at something of a premium), these units are usually unpowered, with a few notable exceptions (most of the Meyer stuff is powered for example).

Once you get past the 'speaker on a stick' sort of level, then the savings in cable that come from running one (albiet possibly a multicore) speaker cable to a box rather then speaker, power, signal and (sometimes) control tend to favour the unpowered box with an amp rack or racks on the deck.

Power distro is an issue in either case (but less of one then you would think), and there is something to be said for having the amp racks where you can get at them (as opposed to 60 feet up where you have to climb the stucture).

Give you a flavour of the sort of things in use (even at the relatively small end), at work I have a modest Nexo rig (20 boxes of Alpha-e), in a 500 seat venue. This is driven by 4 * Camco Vortex 6 amplifiers (3,000W/Ch @ 2 ohms), for 24KW amplifier rated power.
Now those boxes are rated at 107db/W (Half space loaded) so theoretically we could push ~140db @ 1M, we never do of course, and various things would get massively in the way of ever getting near there in reality, but in theory.....

There are some things that may not be immediately obvious when thinking about design for this application:

Truck pack - The things should pack neatly across the width of a standard truck without leaving too much wasted space.

Arrayability - Especially with narrow boxes, we will often want to align several to cover the required angle, this is tricky WRT interaction (particularly in the crossover regions), and tends to be what separates the men from the boys in sound reinforcement speaker design.

Pattern control - with all those open mics on stage having any major lobes off the back is BAD (Causes feedback problems), and the pattern off the front should generally narrow gracefully with increasing frequency without excessive lobe formation (causes comb filtering), this actually imposes a minimum size on the box quite independent of the area needed to physically fit the drivers.

Electrical (and mechanical) robustness, amps WILL be driven hard into clipping (and if the DSP stops the amps being clipped they will clip something earlier in the chain), power may be from a dodgy generator with serious flat topping, poor speed control and a dodgy neutral (think about what happens to a unbalanced three phase load) design to deal with this, boxes will be dropped off the loading dock, or aligned with the fly cradle with crowbars or by being kicked into position, monitor wedges will be stood upon and have beer poured into them.....

Once you get above a certain level you largely stop paying for sound quality and start paying for things like a well thought out flying system and good software array models (Which is far more important then how a box sounds in isolation), and at that point, while everyone has preferences any of the rigs are just fine if setup appropriately to the venue (But can be dire if you get it wrong).

Regards, Dan.

[sumaudioguy]

You should have a look at sites like McCauley, Peavey, Electrovoice, Meyer, and so on and read there white papers and inspecct their gear. Pseudo arrays are now popular with many offerings.

Most portable stuff is about loud. Installed systems more about performance and reliability. For large installs Peavey is the wide leader in the U.S. and has 33% of the world market last time I checked.

[imix500]

Originally Posted by sumaudioguy

You should have a look at sites like McCauley, Peavey, Electrovoice, Meyer, and so on and read there white papers and inspecct their gear. Pseudo arrays are now popular with many offerings.

Most portable stuff is about loud. Installed systems more about performance and reliability. For large installs Peavey is the wide leader in the U.S. and has 33% of the world market last time I checked.

Depends,

For instance, the company I work for does the MET Opera and NY Philharmonic parks tour in the summer. These are systems that could easily support rock, r&b, whatever. But those shows are about quality way more than volume. Though live orchestral reinforcement demands the ability to get stupid loud for very short amounts of time.

Some concerts seem to be about loud above everything else, but that is mostly up to the engineer. Quality is there at that level of equipment, but is not always taken advantage of.

Peavey may have the market, but that's based on volume of all their lines. They released a large format line-array a few years ago and many tried them, but not many A-level acts are still using them. Otherwise, you would be hard pressed to see a Peavey product that's not backline at a large concert.

[dmills]

Peavey hardly counts as a major player at the top level, look to (in no particular order) EAW, Nexo, L'acoutics, D&B, Meyer, Function 1, Turbosound (At least over here, it is a bit variable by region)...

Where Peavey has a lot of share is in small bar band type systems where the fact that it is cheap and relatively robust counts for a lot.

Now to be fair, some of the Peavey architectural acoustics stuff is quite nice, but for an 'A' list act, just the name blows any real chance of it being accepted.

I would second imix500s comments, any of the top tier rigs are perfectly usable for any style as long as they are setup correctly.

It does really help to have headroom for days when working live, hence that stupid loud rig at work, average power is **Maybe** if I am feeling like **loud** 1% of flat out, but it does not clip on millisecond transients, and yes it does show.

Regards, Dan.

[sumaudioguy]

Originally Posted by dmills

Peavey hardly counts as a major player at the top level, look to (in no particular order) EAW, Nexo, L'acoutics, D&B, Meyer, Function 1, Turbosound (At least over here, it is a bit variable by region)...

Where Peavey has a lot of share is in small bar band type systems where the fact that it is cheap and relatively robust counts for a lot.

Now to be fair, some of the Peavey architectural acoustics stuff is quite nice, but for an 'A' list act, just the name blows any real chance of it being accepted.

<snip>
Regards, Dan.

I do not wish to argue. You need to check facts. Peavey is number one by a wide margin in large installs in the U.S. and 35% of large installs in the world. Peavey includes MediaMatrix, Crest Audio, Architectural Acoustics, and Sanctuary Series to name a few. Peavey is the only 5 year warranty on pro and your thought that Peavey would not be taken seriously simply shows you are not a pro though you may work the field. Dissing Peavey as other than number one just will not work, sorry. I will admit Peavey just does not have the snob appeal for those who wish to pay more and get less because Peavey does not gouge like Meyer and others do for equipment lacking Peavey's quality and reliability. As for major players, Peavey is always the go to choice for quality and product. Where else are you going to find items like MediaMatrix? No other manufacturer has anything close except Klotz.

[imix500]

Valid points, but do consider that they acquired Crest and others. They don't really get to have the credit there. Media Matrix was cool ten years ago, but it's pretty antiquated stuff now.

[Xoc1]

Some large PA systems have comprehensive online manuals you can download
For instance Turbosound Flashlight
ftp://ftp.turbosound.com/user_manuals/flashman.pdf
or L'acoustics V-DOSC
L-ACOUSTICS - Products - V-DOSC
and click on manual to download.
I'm sure there must be others.