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Generator for Small Live Sound Rig

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Generator for Small Live Sound Rig

Postby maskedwarrior » Wed Mar 21, 2018 3:06 am

Hello,
Quick question to those far more qualified than myself.

I have a small theatre company and we use an LD Maui PA, a laptop and an LED Lantern.

The PA says 600VA MAX on it
The Laptop magsafe says 60w
The LED Lantern says 49w (max total)

An outdoor venue is interested in booking us but has just got in touch today to say there is no mains power and has asked what our power needs would be so they can hire a generator.

So, in my naivety, I thought one generator was much the same as the next in most uses. However I've since done a bit of reading and the feedback seems to be, for use with delicate electronic equipment, like sound gear, you need a generator with automatic voltage regulation (AVR), which is powerful enough (has a big enough flywheel?) to handle the voltage drop associated with base peaks etc. Is any of this information right?

I have also read horror stories about dodgy gennies bricking good gear. I know people like to intimidate on forums (except your good selves of course) however, I am inclined to err on the side of caution here, or at least ask for advice!

Our sound design uses some atmospheric bass and sub base, so may I'll need something that'll handle that?

So, I need to make a quick inquiry of you:
- What should I say to the venue?
- Would you request a minimum standard of genny and someone qualified to use it?
- Would you not plug your gear into a generator with questionable provenance?

I could ask them to provide a generator AND PA - I could use my laptop on battery, and use my (recently acquired, thanks SOS) isolator to plug into their rig. Thus not plugging my PA or gear into their generator at all.

Any advice would be great, thank you so much in advance!
Tony
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Re: Generator for Small Live Sound Rig

Postby resistorman » Wed Mar 21, 2018 5:33 am

I am totally unqualified to answer this, but if your equipment uses universal power supply specs, you have a leg up!
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Re: Generator for Small Live Sound Rig

Postby ef37a » Wed Mar 21, 2018 7:35 am

I am similarly unqualified (where's Dan Mills when you need him!) but the latest generators use "continuous conversion" that is the engine drives a DC generator (alternator) and can thus run at varying speed depending on load but the DC is converted to (50?) Hz AC by an inverter. This give much better fuel economy and probably a 'cleaner' waveform?

It would be nice to have a "True Sine wave" waveform but I think such gennys are rare and expensive. "Modified sine" seems to be well tolerated by most modern kit?

1kVa would seem to be big enough but do genny people 'massage' their power rating like some amplifier mnfctrs do? !

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Re: Generator for Small Live Sound Rig

Postby Sam Spoons » Wed Mar 21, 2018 11:38 am

I am, unofficially, qualified to answer this one as I run my rig from a genny two or three times a year.

The 'correct answer' is to specify a 6KVA diesel AVR genny but they are very heavy (100kg+) and very noisy and smelly. An AVR or 'Digital' Inverter genny is essential for peace of mind (but I have run the DL1608 on a much bigger rig from a 2.6KVa 'hire shop' genny with neither and suffered no ill effects (not that I would recommend it mind you). If it was me doing your gig I'd ask for a Honda EU30i or a Hyundai HY3200SEi or equivalent (used one of the latter last year, very quiet and solid bit of kit, very tempted to upgrade the Kippor). That will give you plenty of reserve power and a longer run time to avoid the need to refuel on site.

The Genny I have is a kippor IG2000 (1.6KVA Inverter generator)https://www.energygeneratorsales.co.uk/kipor-generator-sales/product-detail/kipor-ig2000p-16kva-digital-suitcase-generator?gclid=EAIaIQobChMI--bc2I_92QIVp7vtCh0RDwCzEAQYASABEgLabvD_BwE bought off ebay for £200. It's pretty quiet, has been pretty reliable (only fail was my fault and caused by dirty fuel) and runs my 'big' (around 6kW) rig happily for three hours or so on a tank of fuel. It doesn't specify whether it's pure sine wave or modified sine wave (which I believe means 'square wave' :headbang: ) and as Dave says Pure Sine Wave would clearly be better but so far my gear seems happy enough.

My rig on these gigs is 1 x EVA sBa750 sub, 2 x QSC K12, 3 x Yamaha DXR10, 2 x Alto TS110a and a Mackie DL1608 plus some backline so rather bigger than you have.

Bear in mind too that some venues, particularly council run ones, don't like petrol as a fuel on site, the last one I worked at were happy as long as I didn't refuel on site.

All the above is my experience over several years and I am happy following my own advice. However when I first mooted the idea on here several more experienced contributors said it would end in tears. Here is that original thread http://www.soundonsound.com/forum/viewtopic.php?f=26&t=36681#p335876 The rig has grown a little since then but the 'ebay special' genny still copes fine.

I will point out that all the above is my personal opinion gleaned from a few small gigs, not a expert assessment so please read it in that context.
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Re: Generator for Small Live Sound Rig

Postby maskedwarrior » Thu Mar 22, 2018 3:05 pm

Thanks for your replies everyone!

Sam Spoons, I actually found your thread as I was researching for this and noticed you were in a similar position to me, only you'd done all your calculations amazingly well (all of which went over my head) and fought your corner against a few dissenters, only to be vindicated in the end. Good stuff :thumbup: And your gig looked very cool indeed, on a beach wasn't it?

I was hoping you'd reply, so thanks.

Your suggestions are extremely helpful and I actually pointed the venue to this thread to take a look at your advice. Thank you very much, and I'll be back in touch with more questions I'm sure.

Best wishes!
Tony
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Re: Generator for Small Live Sound Rig

Postby Sam Spoons » Thu Mar 22, 2018 3:22 pm

You're welcome.

TBF I wouldn't have chanced my little genny on a high profile gig but for the stuff I do it's proved pretty good (as long as I clean the carb every six months or so :blush: ). The main downside of such a small unit is run time, with the full rig it just manages 3 hours so for an all day gig I'd like something a little bigger. Bigger petrol 'silent' gennys are quieter too FWIW.

If they're hiring in then the 3KVA (ish) gennys I mentioned would be a good choice (a local radio station ran their OB truck off a 4KVA Honda EU4.0i at a gig I did a few years ago). If somebody is buying then the Hyundai HY3200 looks like a brilliant compromise between cost and power. Definitely considering one myself.
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Re: Generator for Small Live Sound Rig

Postby Mike Monte » Wed Mar 28, 2018 6:12 pm

I use a Honda eu3000is generator for my (not so loud) remote sound gigs. I own one, but, my local Home Depot also rents them for under $100.00 per day....

(If your gig is a bit more involved, I'd rent a Honda 7000/6500 inverter unit..which is also available for rent at my local Home Depot..)

I highly suggest that YOU rent the generator.. If you leave it up to a venue, who knows what you'll end up with....yes, I have had some negative experiences with venue supplied generators...
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Re: Generator for Small Live Sound Rig

Postby Sam Spoons » Mon Jun 08, 2020 10:23 pm

Just looking back over this subject and a possible issue I have had since is that of heath and safety, if you hire the genny yourself you are responsible for running it safely but if the organisers or venue hire they take on that responsibility and, if necessary, that of getting a qualified electrician in to sign the installation off. Aside from the direct cost implications there are potential PLI issues.

If you are or have staff who are qualified then no worries but if not.....
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