Hi All,
My function band has had a gig enquiry and we would need to be powered from a generator. This would be the first gig where we've supplied and run our own sound system, along with the rest of our equipment, from a generator, and I am unsure how to go about making sure the generator is of a sufficient size.
I have 0 experience in generators so I have no clue if all our equipment will explode if the wrong generator is used! Is there a minimum size of generator that I can tell the client that we need? Otherwise, how do I work out what is required?
Vague details of gear:
Digital mixer,
2x Mackie SRM450 tops,
2x JBL subs,
2x active floor monitors,
guitar amp,
keys amp,
bass amp,
5 LED par lights.
If accurate wattage values are needed then I would need to do some research and get back to you..
Any help and advice would be appreciated!
Cheers
Comments
The generator provider wants to know exactly how much power we need so i'm going to have to add it all up.
I was struggling to find the power requirement for every piece of equipment in the band. I found an article, http://www.soundonsound.com/sound-advice/power-electrical-safety-stage, which advises to multiply the output power by 1.4 to get an approximate value for mains power requirement.
The total I found for the band's equipment was 8.7kW, which works out at around 11kVA according to the calculator at the link posted by @Christophe.
I multiplied that by 1.5 to add 50% headroom to the total, which finally brings me to 16.5kVA.
This is the value I plan on giving as the bare minimum to clients requesting to power us via generators.
I will let you know if/when anything goes wrong!
Thanks for the advice.
Pair of 1000W subs, pair or 1000W tops, 500W monitor and a 200W monitor, 900W bass cab, 200W keys amp, 30W guitar amp and 5 60W lights.
Multiply that by 1.4 as the article says and it's pushing 8kW. Do you think that's too high?
Thanks
SRM450 tops aren't 1KW each, those things thermal before they ever get near their rated RMS power and they are quite efficient ... you wouldn't need 1KW for both .... maybe your thinking peak power not RMS ?
This is your current per Mackie 450.
http://mackie.com/sites/default/files/PRODUCT RESOURCES/SPECS/Spec_Sheets/SRM350v3_450v3_SS.pdf
And I bet in rehearsals you run it all off a couple of 13A sockets....what does that tell you?
https://www.studiowear.co.uk/ -
https://twitter.com/spark240
Facebook - m.me/studiowear.co.uk
Reddit r/newmusicreview
The bass amp likewise - it's very unlikely to be drawing more than 500W, probably less - and the keyboard amp 150W. The odd one is the guitar amp, which could be putting out well *over* 30 if it's cranked because it will be driven into distortion, but the maximum draw of something like an AC30 is around 125W, so that's still less than 800W for the backline. 3KW total so far… the mixing desk could be around 100W and the lights 300W, and you're only at 3.4KW. You'd probably be OK with the whole lot run off a single 13A socket (3120W).
A 5KW generator should be more than enough really.
"Take these three items, some WD-40, a vise grip, and a roll of duct tape. Any man worth his salt can fix almost any problem with this stuff alone." - Walt Kowalski
"Only two things are infinite - the universe, and human stupidity. And I'm not sure about the universe." - Albert Einstein
To be honest I just added up the maximum power of every part to be on the safe side. I did ask the client to pass my number on to the generator supplier so hopefully they will be in touch..
The amp is a mesa lonestar special, if that makes any difference?
@Danny1969
Yes, I was adding up the peak power.
Feedback
I posted above about this:
"I was struggling to find the power requirement for every piece of equipment in the band. I found an article, http://www.soundonsound.com/sound-advice/power-electrical-safety-stage, which advises to multiply the output power by 1.4 to get an approximate value for mains power requirement."
I realise that it's not a 100% accurate way of doing it but it was an easier solution than finding exact specs for every piece of equipment.
Our old lights on the otherhand are voracious - 4x500W bulbs per unit = (circa) 2Kw / 8amps each
Feedback
What you have to consider is the average current draw when playing in your normal manner then have plenty in reserve ..... but you don't need to go crazy. You won't ever be using anything to it's maximum current draw, any speaker will be howling in feedback and thus turned down well before that happens. A Mackie SRM450 will thermally shut down well before that happens.
My own company 2020Studios typically use 6KVA to 10KVA generators for a lot of outdoor work and that's running a 4.2K of HK PA , band backline and 4 to 6 stage monitors with a couple of rows of LED PARS ... I haven't had any problems when mixing all kinds of bands outdoors with this setup. You can generally expect in normal use to get about 76% of the KW you need from the generators KVA rating.
Here's one of our typical outdoor PA's running from an 8KVA jennie
As you can see it was enough for Freddie and Brian
Corporate gigs can be so sad ..... quite amusing though
Super helpful, thank you!
By the way that inflatable stage looks like a great setup
Any digital equipment with a shut down procedure should always be on a UPS ... anything that you turn off by cutting the power with a switch with no shut down procedure should be fine, although repeated on \ off \ on \ off power can cause problems
No idea about AxeFX or Kemper .... do they have a shut down procedure ?