hi all

I need advice with an assignment I have,

it is to design a system that has to cover a wide variety of events/venues, mainly live music and cover 50-1000 people

I have most of it laid out but I am unsure of what the pa size should be about, currently I have a 7k (LF:4k LMF:2k HMF:600 HF:240) system in mind (I have looked online and could only find http://www.whatpa.co.uk/howmanywatts.asp as any sort of guide) and whether delay towers are something to look at to include.

thank you for your help

G

Hi Graham. Is this one of Gwill's assignments from the good old University of Glamorgan? As long as you explain why you have chosen whatever you have chosen, you will be fine. Have about 10k, but make sure that it will split down to be smaller, but still have full range and good quality. I done this assignment 4 years ago. This assignment is really about explaining why you have chosen the equipment and that you understand that not all venues are the same. If you are stuck pm me and we can have a chat.

shouldnt this be on the next generation forum? and are you asking us to do your assignment for you?

it's a Uni of Glamorgan one for Pete

I thought it was more on the equipment choice especially on the detail of the cables needed to make it all work



maby I did not see that section I just jumped straight to sound, my bad

no, not at all, especially on a forum where my lecturer may well be watching
I am just asking with those parts as I am not sure with size of PA, I am all good with equipment selection and that (well at least I hope )




I stuck in the bit about delays as in a few of the theatres I have worked it they use them but for an outdoor event about that size ??? I have only been to reading/download/bestival and there allot larger




G

Delays will be largely unnecessary. They only exist to make up for the loss in HF you get over greater distances. For systems going into multiple venues you'll want something which is equally capable when it comes to anything from a village hall to larger theatres. Have you been given a budget, as there are some companies which offer systems which can do pretty much anything as long as you know what you're looking for and have the right budget...

alright, that makes sence.

yeah £75k in vat for everything down tho the pint you give yourself afterwords for doing a good job

ive ideas floating arround like using the floor monitors for the main PA on the smaller 50 people side of things



so is there a recomended guide to PA watt size for size of audience arround (or even guide to SPL size for size of audienceas ive read in a book or two that this is what should be looked at preferably)

G

I think the point that has to be remembered here is the 50 to 1000.

So the 7K rig is going to be split down how? to do the smaller events. A 4 way rig at the bottom end of the scale would difficult, depending on the venue size.

Look at some currently available solutions from the likes of HK, RCF, dB, JBL etc, who all supply modular systems that could easily entertain both ends of the spectrum, with a little configuring. Look at the tech specs of the rigs and their footprint.

It's intresting that you've quoted wattage figures in the Original Post, and from an external website the wattage required, without any consideration to the efficiency of the PA, the SPL or the room acoustics or the type of event.... all of which have a bearing on the final solution.

Nothing is black and white.

If you've looked online and only found the link you submitted, then I think, if I were you, I'd do a little deeper research, the info is out there, you just need to find it

As far as SPL at the venue goes..... that could be down to the numpty with the SPL meter

I don't have any particular knowledge of the Glamorgan course but know it has a decent reputation so suspect they want you to do this properly. As lightsource says, if you're working to a wattage figure your're doing it wrong. Any site that claims to tell you how many watts you need per person is wrong and should be ignored. The efficiency of modern speaker cabinets can vary enormously and you'll have to do all that boring math to calculate the coverage and power required with whatever system you choose. However, you'll get a better learning experience (and a better theoretical system) by doing it this way.

Since this IS theory with no money being spent, stick to well=known manufacturers of high quality kit. You'll find their web sites are crammed full of the technical details you need for your calculations. Choose a range that is specified as suitable for scaling a system (50 to 1000 people, remember), select a target SPL across the audience, then calculate away.

That's the way you'll eventually do it professionally--except then you have to factor in budget as well which makes things much harder!

Bob

You may want to look at the new d&b T-series. The speakers can be used either by themselves (by rotating the horn) and a subwoofer, or they can be arrayed (effectively) to allow you to cover larger audiences.

The amps have delay/crossover/limiter settings etc built in so the system would be 'self-contained' without any need of extra processing.

cool ill have a look at them, ive been looking at some of dB and HK's stuff

ive been playing arround with the though of two martin audio WT3 and two martin audio WS18X (per side) thinking it can be broken down in size and eventuly the subs lost or replaced with smaller ons as the audience size decreaces then in the end replaceing them with with the monitors dB arena 12 / arena 15 which I might add in a small some smaller power subs to be used with it (none of this is set in stone)

thats what ive been thinking for useing the pa at diffrent sizes throughout the system



"wide variety of events/venues, mainly live music"


thats all that is said about the venue and events its to be used for not even saying where its is used both outdoors and indoors therefore im treating the system as pa hire rig


thanks

G

Don't confuse dB Technologies with d&b Audio, two completely different companies there.

dB and HK both make some good boxes, but they're aimed more towards the budget end of the market (HK more upper-budget end).

The Martin Audio kit is very good indeed, but WT3s aren't exactly what I'd call 'multipurpose' speakers. They're great boxes, but for a crowd of 50 would be ludicrously overkill. The reason I suggest the d&b T-series is the speakers themselves are very small (2x ~6" drivers + 1.4" horn), can be used either by themselves or arrayed (by rotating the horns). They'll put anything made by HK or dB to shame, and I would expect you'd find they outperform the larger Martin Audio boxes.

At the risk of "doing your homework"....

....another advantage of d&b audiotechnik (besides making great sounding, efficient boxes) is that (for your purposes) the specs on their website will be very useful for the calculations you need to do.

Bob

Bit of practical experience:
We have a custom pa with 2*18"Wbins+3*[2*10"+horns] per side: the system is based on UK manufactured parts with 2/3 way analogue crossovers (with time delays) and (with quite a bit of careful repatching and balancing) is usable as:
1.Full PA about 7kw 2. Half PA 1*18+ 2 mid hi's 3. Light PA 1*15 (from another system)+mid hi 4. Only mid hi units for full range the 2*10+horn allows up to 300-500w with a passive crossover and are ported ! ... another full pa option was to array the midhi's... but business has not justified the additonal expense of a structure and more bass & mid hi units (remember arrays must approach a usable wavelenght/frequency height...) so that is on the autocad-drawing board still as are the purchase of digital X-overs. Perhaps when people start smiling again and sunny times come !! What I am getting at is: you only have Xpounds or Euros to invest therefore equipment must work and not rest in its storage space - there it only takes up space and becomes a free home for spiders, cockroaches et al.

cool thanks for your help,

think ive got it all sorted with what I asked

GeeGee

feel free to dicuss this more for others to stumbel across if wanted