Looking for tips on a battery-powered PA

[psjon]

We are playing a wedding dance, but the client has also been consulting me on sound for the wedding ceremony which is outdoors on a grassy hillside 400' from the nearest outlet. I did see this piece of rental gear http://www.emionline.com/emirentals/spe ... owered.php which looks intriguing. Is there any other noiseless solution to power my powered Peavey mixer: http://www.musiciansfriend.com/pro-audi ... c=3WWRWXGP? A generator is not not an option. I have a pair of J10s to go with it.

[byacey]

They have put you in a very difficult situation by ruling out a generator. Any battery operated inverter capable of any amount of power will kill even a 12V car battery fairly quickly unless it's in a car with the motor running.

The battery operated lectern PA systems won't cut it. They may be OK for speech, but once you start running music through it, you'll turn the cones inside out, and experience the same problem with dying batteries.

I would tell them they have two options:
Rent 400 feet of AC cable of sufficient wire guage to power your gear,
or rent a small AC generator. The generators nowadays are very quiet. If you moved it 50 feet away backstage, it won't create a disturbance. Get one rated for 2 or 3 thousand watts, and that should run your PA gear and maybe even a couple lights.

If you demonstrate the band playing through one of those blue megaphones, they'll quickly see the merit of a generator.

[ncgrove]

The XR1212 claims to only rated for 120V, 275W mains power. If my math is right, that's less than 3 Amps it's going to draw.

How much do you want to spend? You might be able to pull it off with a couple of deep cycle marine batteries (pretty expensive) and an inverter. I'm not sure how efficient inverters are, so you'll have to factor in that as well. The power amp shouldn't have to work too hard to run the J10s to their limit.

You might run into trouble if you want lights and instrument amplifiers, though. Or maybe not.

[psjon]

The XR1212 claims to only rated for 120V, 275W mains power. If my math is right, that's less than 3 Amps it's going to draw.

How much do you want to spend? You might be able to pull it off with a couple of deep cycle marine batteries (pretty expensive) and an inverter. I'm not sure how efficient inverters are, so you'll have to factor in that as well. The power amp shouldn't have to work too hard to run the J10s to their limit.

You might run into trouble if you want lights and instrument amplifiers, though. Or maybe not.

Just to clarify - for battery operation I'm just talking about the ceremony part (not the reception afterwards) in which I'd only be running the Peavey XR1212 with a couple of mics and an MP3 player (no live music - sad, I know). So other than the Peavey XR1212 there'd be no other powered gear would be involved.

[psjon]

What if I just rented 4 100' extension cords of 12 gauge wire? Would the heavy gauge wire mitigate any negative effects of the long run? Mayne I'm just making it too complicated.

[Bruce Weldy]

What if I just rented 4 100' extension cords of 12 gauge wire? Would the heavy gauge wire mitigate any negative effects of the long run? Mayne I'm just making it too complicated.

Sounds like you only need to make this run for the ceremony - which probably means a preacher's mic and maybe a little background music. 400 feet is a long run for 12 ga. But, I don't think you'd have any problem pulling this off like that. Keep the volume down on the music and the power consumption low - you should be fine.

And you are right to rent some cords....I just bought a 100 footer an hour ago - over $80.....for a gig I have this Friday.

[SirNickity]

I'd borrow a car amplifier before running a PA amp off an inverter. Just sayin.

[Bryce]

With a 400 foot ac power run, think about your grounding situation...

[byacey]

The XR1212 claims to only rated for 120V, 275W mains power. If my math is right, that's less than 3 Amps it's going to draw.

How much do you want to spend? You might be able to pull it off with a couple of deep cycle marine batteries (pretty expensive) and an inverter. I'm not sure how efficient inverters are, so you'll have to factor in that as well. The power amp shouldn't have to work too hard to run the J10s to their limit.

You might run into trouble if you want lights and instrument amplifiers, though. Or maybe not.

That's 3 Amps at 120V. At 12V your looking at about 30 Amps, which will drain a battery real quick. I think the 12 AWG extension cords are a better idea. An automotive power amp will run into the same dead end, lot's of current draw at 12V;You don't get free power from nothing.

Grounding shouldn't be an issue as long as 3 conductor extension cords are used and the equipment is all properly connected with 3 wire power cords. If you're really worried about it, feed it from a GFI power receptacle.

[Tom Smit]

The battery powered PA that was linked to, only puts out 60w on DC. A generator several feet behind a 2-plus-1 stack of straw bales, will not be heard, especially if it's a Honda.

[Bruce Weldy]

The battery powered PA that was linked to, only puts out 60w on DC. A generator several feet behind a 2-plus-1 stack of straw bales, will not be heard, especially if it's a Honda.

That's also a good option.....

No matter what you do, it's a PITA for 15 minutes of sound.

[biggerrigger]

If it a low powered setup you could use any number of the T-Amps on the market to pull it off. I have a Dayton model that is 50watts per channel and fits in the palm of your hand. I have built a battery pack from Lipo cells used in RC airplanes and get several hours run time out of this combo.

[DJ Higgumz]

my vote a generator behind a barrier like said above. 400 feet runs and your looking at shock hazard. which sounds better a purring generator or the yelp of a fried guest?

[byacey]

A 400 foot AC run is no more of a shock hazard than a generator that is properly grounded, as they should be. The generator however, is a more expedient solution as line loss is no longer a concern.

[thekl0wn]

Though a small generator would still be the first choice, I've ran cheap active speakers off an inverter many times. Last weekend we ran a pair of 15" Behringers actives off of 2 deep-cycle tractor batteries at war volume for 8+ hours out on the lake. Then again, if this gear was destroyed, I didn't really care.