generators - noise

claudio rietti · February 13, 2007

what is generally considered to be an acceptable decibel level for shooting sync sound in regards to a generator at close proximity to the action. I've sourced out a 10K gennie at 70 dB. Seems to me that this is much to noisy for our purposes.

Thanks,

Claudio

claudio rietti · February 13, 2007

Also, when would a 3-phase gennie be necessary?

Kevin Zanit · February 13, 2007

"3-phase gennie be necessary"

When you need 3-phases . . .

The additional hot leg gives you more options as far as cable run and load balancing is concerned.

A far as noise level goes, I don't know the db figures, but most "movie quiet" generators are pretty quiet. That said, they can be too loud at times. You may find yourself parking it around a corner and needing to run a good amount of cable. Depends a lot on the location.

Brian Baker · February 16, 2007

Aside from the need for a lot of power or to more evenly distribute power (as mentioned above), another reason you may need a 3 phase generator is for varying voltage levels.

Most (if not all?) 3 phase genies allow for voltage adjustments; weather it be in balancing small increments, or moving between 120v and 240v.

Also, on shoots where we were incapable of parking our genny far away, we'd build goal posts (speed rail across two Junior stands -- like tripe riser combos -- held by Big Ben / Cheeseboro clamps) and spring clamp several sound blankets to them.

Just be careful when using sound blankets not to cover the Gennie's vents.

Best,

BtB

Paul Bruening · February 16, 2007

Other than blocking (hiding around building, walling with plywood, etc) or adding a car muffler to the unit you can high-pass filter some of that gennie grumbling out during shooting. Some mics have the filter built-in. You can also rent/buy the filters. If only a little of the noise makes it onto tape, you can turd polish some of it out in post. You can also mask some of it with other noise that seems appropriate to the situation during post. Situations don't always lend themselves to perfection during the shoot. A little of each of the techniques listed above, in various combinations, end up being needed.

Chris B. Cornell · February 16, 2007

Is it not feasible to do a long power run? Power cable is a relatively low cost for rental, and a nice 3 phase genny will allow you to increase voltage to compensate for the line loss on your long power run.