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[Cesar Acosta]

I rent out a small PA, which consists of 2 Alto black 12 tops and usually one Alto black 18 sub. Spec sheet rates each speaker at 6A. Even just using those 3 I'm going over the 15A for the wall outlet. I'm also using 4 LED par lights and a mixer. There's usually no other sources of AC power where I rent this system out, just regular wall outlets. Should I be concerned with the power requirements? I haven't had any problems yet, nor have I noticed and heating at all in the cables I use.

I'm also concerned, since the full system would consist of two tops, two subs and a couple monitors. I don't know the power draw for the monitors, but it should be much lower, since the monitors are only 600W peak, compared to the 2400W peak of the other 4 speakers (I know how much everyone here hates peak watts lol I'm just using them for comparison, since they are the same brand monitors and mains). That would be 24A for the 4 main speakers, plus maybe a couple Amperes for the monitors, plus the LED lights and mixer. Maybe 28A to 30A?

So should I be concerned? What can I do to be as safe as possible? Most venues are just at house parties and only have a standard 15A wall outlet available.

[Tim Weaver]

How many times have you blown the breaker?




I kid. You'll be fine. The cabinets would only pull that much juice if they were well past limiting and actively on fire.

[Tim McCulloch]

I rent out a small PA, which consists of 2 Alto black 12 tops and usually one Alto black 18 sub. Spec sheet rates each speaker at 6A. Even just using those 3 I'm going over the 15A for the wall outlet. I'm also using 4 LED par lights and a mixer. There's usually no other sources of AC power where I rent this system out, just regular wall outlets. Should I be concerned with the power requirements? I haven't had any problems yet, nor have I noticed and heating at all in the cables I use.

I'm also concerned, since the full system would consist of two tops, two subs and a couple monitors. I don't know the power draw for the monitors, but it should be much lower, since the monitors are only 600W peak, compared to the 2400W peak of the other 4 speakers (I know how much everyone here hates peak watts lol I'm just using them for comparison, since they are the same brand monitors and mains). That would be 24A for the 4 main speakers, plus maybe a couple Amperes for the monitors, plus the LED lights and mixer. Maybe 28A to 30A?

So should I be concerned? What can I do to be as safe as possible? Most venues are just at house parties and only have a standard 15A wall outlet available.

What kind of program material?  Typical rock/pop/country music has a pretty wide dynamic range, whereas EDM, rap, etc tends to have a much more limited range (everything is loud, all the time) and will draw more energy than typical live music.

That all said, you'd likely need to be running your system into limit, continuously, before tripping an AC mains breaker.  Your LED lights may pull up to 2 Amperes each (check the label) so you might want to put them on another circuit if you operate this way.

[Mike Sokol]

So should I be concerned? What can I do to be as safe as possible? Most venues are just at house parties and only have a standard 15A wall outlet available.

Here's an easy way to think about it, just to see if you're in the ballpark with power. Due to crest factor (the peak power to average power ratio of most music), your power amps will likely only draw an average of around 1/8 of their rated power from the AC outlet. So a 1,000 watt amplifier will probably draw around 125 watts from the wall outlet on average. Now for the second part of the trick, you should know that wattage divided by voltage equals amperage. So, if you divide your 1,000 watts by 120 volts you'll get around 8.3 amperes of current, and 1/8 of that is about 1 amperes. So for a quick calculation, just add up all of your amplifier wattage, divide by 1,000, and that's how much average power you'll probably draw from the wall outlet. So that 1,000 watt amplifier will probably draw around 1 ampere average, which is 120 watts. Now using that logic, you can multiply your 15-amp receptacle by 1,000 and see that it could likely power up to 15,000 watts of modern amplifiers playing most music with a normal crest factor.

Of course as indicated by others here, EDM and Rap can draw enormous amounts of continuous bass power, so you might have to derate your calculation by a factor of 2 or more for that style of music driven into serious clipping. Still you should be able to get at least 5,000 watts worth of modern amplifiers running heavy-bass music on a single 15-ampere outlet. Also as noted, lights don't work like this since they need continuous power when they're on, so even 12 LED PARs could eat up half of your available amperage from a receptacle. If possible, put them on another circuit.

[Cesar Acosta]

Fortunately, in this case, EDM isn't much of a trend here. If I'm playing recorded music it's along the lines of current pop music or, rarely, rock music. Most of the time it's a small band that plays electric-acoustic guitars and an electric bass. From what I've been reading, I should be fine with that kind of band even with all speakers and monitors. Thanks, everyone. I highly appreciate your advice!

[Brian Jojade]

Since audio power draw is extremely dynamic, it can be difficult to gauge exactly what you need.  If you crank your speakers up to max and play very compressed music, yes, you potentially can trip a breaker.  It'll probably sound like crap far before that happens though.

Now, blowing the breaker isn't the only concern.  Making sure that you have stable voltage at the speakers is pretty important.  Your average power may only be a couple of amps, but for peak demands, if you run on long thin extension cords, you could see some significant voltage drop.

If you use the common 1/8 power, and your average draw on a speaker is 200 watts, when it peaks, you are pulling 1600 watts. This is for a very short duration, and won't trip the breaker, but the resulting voltage drop when current increases might be enough to put a speaker into protect.

When calculating voltage drop, I like to use worst case scenario, and make sure I use heavy enough cable so that I know I won't drop below 108 volts.

[Stephen Kirby]

Your LED lights may pull up to 2 Amperes each (check the label) so you might want to put them on another circuit if you operate this way.

I have a small DJ type rig with a couple of flat 4 fixture things on poles, 4 more cans in back along with a 36" bar.  Running a typical color changing program I got exactly 2A out of the whole rig.  Maybe if everything was on it might pull 6-8A.  Similar to the way the audio doesn't run flat out.

[Tim McCulloch]

I have a small DJ type rig with a couple of flat 4 fixture things on poles, 4 more cans in back along with a 36" bar.  Running a typical color changing program I got exactly 2A out of the whole rig.  Maybe if everything was on it might pull 6-8A.  Similar to the way the audio doesn't run flat out.

We have a bunch of different LED PAR type fixtures, the name-plate rating is usually 1.0-1.50A at 120V.  I rounded up. 

With reasonable SPL level I can still see the lighting pulling more current, more consistently, than the audio.

[Frank DeWitt]

This might help
http://www.p3international.com/products/P4400.html

[Keith Broughton]

This might help
http://www.p3international.com/products/P4400.html

These are great for measuring a more constant load.
Have not tried on on an audio amp.

[ProSoundWeb Community]