Power Ratings

[JCC1996]

Hi,

 

I'm running sound for a local youth group's charity concert. Its a variety concert with a total cast of about 15, including singing (solo and chorus), dancing, and acting- all to backing tracks so no live instruments. Its to be held in a church hall with a capacity of about 150, although it unlikely to be full. I know PA's aren't all about power and that SPL comes into it, but I'm looking for a rough idea of what power PA I should look to hire?

 

I had a figure of about 300Wrms in my mind and most hire companies I've spoken to thought this reasonable, but a few said that that was way off the mark and quoted for around 2000W. So could anyone clarify what sort of spec I should be looking at?

 

Thanks

 

Joe

[Oldradiohand]

If cost isn't an option you might as well go for the bigger PA. After all, you can always turn it down.

[TonyMitchell]

Firstly, determine where you are going to place the loudspeakers - to achieve as even levels as possible throughout the audience, as opposed to deafening those closest to a speaker in order that those furthest away can still hear the programme.

 

For the job you've described, I'd probably be taking 4 x E8s, for their 90 deg. horizontal pattern and possibly a Q-SUB, depending on the genre/s of the backing tracks. Some may baulk at it, but for small spaces, a 90deg. box in each corner, facing in, usually works well for me.

 

Whether the cabinets are 300w or 2000w is irrelevant, unless your church hall is like the one I was in a while back in the depths of Gloucestershire, where we were feeding the leccy meter every half hour! The heater under my desk is 2000w and I can still converse on the phone when it's on full. And the 300w speakers you've been offered may be a lot louder than the 2000w ones.

 

 

 

 

 

[JCC1996]

Thanks, I'm afraid cost really is a factor. We're trying to keep cost to an absolute minimum.

[Bobbsy]

This is an impossible comparison to make without more information I'm afraid.

 

As one poster said, a good 300 watt system can be louder than an inefficient 2000 watt system--and that's before we get into things like whether they're talking about Continuous or RMS or Peak and consider coverage angles.

 

Beyond even that, the style of the concert makes a big difference. A series of classics from the musicals is a very different matter to a heavy metal concert.

 

Instead of discussing power with the hire companies, why not give them the dimensions of the hall and the style of the musical and ask which of their systems they suggest. With some details we can probably help you decide (and possibly also identify the fly by night operations from those responding properly to your needs).

[Paul O]

I'm usually a lampie but sometimes get asked to provide sound for small events like this as I have a smallish PA system. As others have pointed out the style of music makes a big difference, particulay how much bass you need.

 

In my case I have a pair of 250W RMS 12" speakers that are fine for general sound duties in small venues but for anything needing more bass I add a 600W RMS 15" sub (as at the event I'd doing this evening) .

[brainwave-generator]

I think you've made this enquiry in a funny order. I assume what you want to do is ask us what system you should need, then ring the hire company and just say "I want this, this and this" because they will be easier to work with if they think you know exactly what you're talking about and can just give you the boxes and send you on your way.

 

The thing is that the absolute opposite is true. Hire companies have absolutely no issue with people coming in and saying "I know how to operate a PA system, but I'm not really sure which one I need". They get it all the time, and they understand that not every event has the extra £150-250 to book a sound engineer on top of the budget.

 

The information you've supplied to the forum - just supply it to the hire company! Forget about asking for an x-number-of-watts system based on forum opinion; just ring them up and say:

 

"Hi, I'm running sound for a local youth group's charity concert. Its a variety concert with a total cast of about 15, including singing (solo and chorus), dancing, and acting- all to backing tracks so no live instruments. Its to be held in a church hall with a capacity of about 150, although it unlikely to be full. Do you have a suitable PA system that I could dry hire?"

 

Rather than asking the forum how many watts you need and then ringing the hire company up and saying "I need a 300W PA System". Because as has been pointed out, you could make a 2000W PA system out of a pair of iPod earphones and an electric heater. If you don't really know what you need, the PA company will suss you out soon enough anyway. Don't be worried about asking for help, the company would much much rather offer you some advice and send out the correct system, than have you turn up knowing exactly what you 'need', and ringing them up at half-past-closing to say "errr it's a bit quiet in here".

 

They will have dealt with similar events a thousand times before, there's a reasonable chance even that they'll have even used the same building, if it's a local firm. Just ask for help, it's better than pretending to know what you're on about and then hiring a turkey when you need a cow.

[JCC1996]

Well, like I said its variety. It has everything from LMFAO's Sexy and I know it, to Hard Knock Life from Annie and everything in between from Johnny Cash to Elvis if thats any help! I'm happy to leave the system to the judgement of the hire company, I just wanted a rough idea to know whether they're 'extracting the michael' so to speak!

[GDJ]

1348325136[/url]' post='452483']

I'm usually a lampie but sometimes get asked to provide sound for small events like this as I have a smallish PA system. As others have pointed out the style of music makes a big difference, particulay how much bass you need.

 

In my case I have a pair of 250W RMS 12" speakers that are fine for general sound duties in small venues but for anything needing more bass I add a 600W RMS 15" sub (as at the event I'd doing this evening) .

 

 

As Paul says keep it simple use an active sub/satellite package to save space and wiring

[TonyMitchell]

I just wanted a rough idea to know whether they're 'extracting the michael' so to speak!

 

 

If you tell us what the hire co have offered you, we may be able to give opinions on that.

 

Are you hiring a complete package? So far, you've only mentioned FOH speakers, what about everything else - mics, desk, mons, playback, etc? How many miked up cast will be performing concurrently?

[JCC1996]

The system is FoH speakers and amps/powered speakers, 8 Channel Mixer, a few condenser/boundary/shotgun mics and all cables. We don't have the budget for radio mics. And I am sourcing monitors from elsewhere. With the exception of one that offered two subwoofers and mid-high cabs, everywhere else has just offered two FoH speakers.

 

Joe

 

Oh, plus a multicore cable.