If you're using it for sound, the Honda EU are the only small gennies I've seen that I'd consider unless you have 300ft of feed and a brick wall. I ran a Briggs and Straton 6K out of the back of my box truck once with 150ft of feed and you could still hear it clearly at the stage. The inverter power for any of the modern sensitive digital electronics is also good to have. The EU3000 can run a smallish sound system (powered mains, subs, 4-6 powered monitors and backline) with no problems.
Whether you pick up generator noise or not comes down to how you use the generator as much as which generator you use. It is possible to use the Honda EU6500 portable generator without hearing the noise if you use them with a transformer that will allow you to move the generator off site (like you would a diesel tow plant), compensate for line loss over a long cable run, and provide plug-in pockets conveniently close to the stage.
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A Distro System consisting of a 60A Full Power Transformer/Distro, 2-60A GPC (Bates) Splitters, 2-60A Woodhead Box distributes power from a modified Honda EU6500is. Even though the generator is 200' away to reduce noise, plug-in points remain conveniently close to set.
To record sync sound in motion picture production without picking up any generator noise, we typically use 200' - 300' of heavy duty 250V twist-lock extension cable between the generator and a Transformer/Distro on set. This is usually enough cable to place the generator around the corner of a building, or to run it out of a van or truck - which is usually all the additional blimping you need with the Honda EU generators. The heavy-duty 250V twist-lock cable eliminates multiple long cable runs to the generator and minimizes line-loss; as well as, eliminates the voltage drop you would have using standard electrical cords.
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60A GPC (Bates) Splitters and Woodhead Box.
To assure full line level (120V) on set, use a Transformer/Distro designed to compensate for the slight line loss you will have over an extended cable run. Use one designed to slightly boost the voltage on the load side (secondary) so that if you were to feed the supply side (primary) of the transformer 240 volts from the generator, 127 volts would come out on the secondary side where you plug in the lights. This slight boost enables you to place the generator further from set where you won't hear it, yet assure that the supply voltage on set does not drop too low.
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60A Woodhead Box running Power-to-Light PFC 800W ballast (left) and PFC 1200W ballast (right.)
Using the Honda EU6500, or new EU7000, will certainly help. The Honda inverter generators to begin with is much quieter than other generators. Part of what makes them so quiet is their "Eco-Throttle." The Eco-Throttle's microprocessor automatically adjusts the generator's engine speed to produce only the power needed for the applied load. They can do this because the inverter technology of inverter generators enable them to run at different RPMs and maintain a constant frequency and voltage.
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Two paralleled Honda EU6500s powering a 12k HMI Par.
Where conventional generators like the Honda EX5500 and ES6500 have to run full speed at a constant 3600 RPM to produce stable 60 hertz (cycle) electricity, a Honda EU6500is only needs to run as fast as required to meet the load demand. Since their engines do not have to run at full speed, and given the fact that an inverter generator generates 20% more power per revolution of the engine, makes the Honda EU6500is substantially quieter than conventional generators and it can be modified to generate 7500W.
For more details on the use of transformers with the Honda EU6500is for set power, and even how to parallel two of them for 100A output, I suggest you read the article I wrote for our company newsletter on the use of portable generators in motion picture production (available at
www.screenlightandgrip.com/html/emailnewsletter_generators.html (http://www.screenlightandgrip.com/html/emailnewsletter_generators.html). )
Guy Holt, Gaffer,
ScreenLight & Grip
http://www.screenlightandgrip.com