Sound Level and Hum

Thomas Wright · 08-22-2008, 04:15 AM

and so then i got a sound fella; fella that records sound, i'm sure he's solid too, and he was getting a hum on some of his takes? anybody else had this issue? i've read about the LCD making a noise but that was in an earlier build and i gleen it was a beep. The fan was not running for takes either.

he's also wondering why there is no gain control for the line input, he reckons there is one for the mic enabled channels- i couldny find none nowhere. and on a shoot i had recently my sound guy- he's solid too- was also dismayed by the absence thereof.

they are stoked however that they needn't have their hard disc recorders and trolleys out so rectification of this would be much appreciated by afforementioned sound, sound chaps.

Ed Watkins · 08-22-2008, 06:05 AM

What a wonderfully British sounding post. I do miss home.

Anyway, there shouldn't be any hum on the audio if it is set to 'line in', and phantom power is off.

In my experience on 'mic in' there is a noticeable hum when the audio is set above -32db. The hum seems to be generated by the pre-amps (speculation on my behalf).

You can also get a 'hum' or static noise if you use phantom power and don't use the RED made XLR -> mini-XLR connectors (they have a resistor in them to drop the levels down).

If you don't use the RED made cables there is a chance you could damage the audio board.
The worst culprit seems to be: no RED cable, using mic in, with phantom power enabled, and having a strong audio peak.
If the board is damaged there will be a strong 'hum' present on the audio channel permanently.

Hope that helps.

Dwain Barrick · 08-23-2008, 09:01 AM

New audio boards are on the way. At Red Day they said that these boards are pro level, the noise will be eliminated and you won't need to use the padded xlr Cables anymore.

http://www.reduser.net/forum/showthr...ht=sound+board

Thomas Wright · 08-26-2008, 08:28 AM

much obliged chaps, pity we'll have to send all the cameras back but good of red to do it free eh wot. (i threw the "eh wot" in for ed, i don't really talk like that)

08-22-2008, 04:15 AM	#1
Thomas Wright Senior Member Join Date: Jun 2008 Location: London Posts: 264	Sound Level and Hum and so then i got a sound fella; fella that records sound, i'm sure he's solid too, and he was getting a hum on some of his takes? anybody else had this issue? i've read about the LCD making a noise but that was in an earlier build and i gleen it was a beep. The fan was not running for takes either. he's also wondering why there is no gain control for the line input, he reckons there is one for the mic enabled channels- i couldny find none nowhere. and on a shoot i had recently my sound guy- he's solid too- was also dismayed by the absence thereof. they are stoked however that they needn't have their hard disc recorders and trolleys out so rectification of this would be much appreciated by afforementioned sound, sound chaps.

08-22-2008, 06:05 AM	#2
Ed Watkins Senior Member Join Date: Mar 2007 Location: Oxford, UK Posts: 645	What a wonderfully British sounding post. I do miss home. Anyway, there shouldn't be any hum on the audio if it is set to 'line in', and phantom power is off. In my experience on 'mic in' there is a noticeable hum when the audio is set above -32db. The hum seems to be generated by the pre-amps (speculation on my behalf). You can also get a 'hum' or static noise if you use phantom power and don't use the RED made XLR -> mini-XLR connectors (they have a resistor in them to drop the levels down). If you don't use the RED made cables there is a chance you could damage the audio board. The worst culprit seems to be: no RED cable, using mic in, with phantom power enabled, and having a strong audio peak. If the board is damaged there will be a strong 'hum' present on the audio channel permanently. Hope that helps. __________________ #646 "Darwin" Check out my RED helper iPhone App iSee4k or my reel at NaturalScinema.com

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08-23-2008, 09:01 AM	#3
Dwain Barrick Junior Member Join Date: Oct 2007 Posts: 29	New audio boards are on the way. At Red Day they said that these boards are pro level, the noise will be eliminated and you won't need to use the padded xlr Cables anymore. http://www.reduser.net/forum/showthr...ht=sound+board

08-26-2008, 08:28 AM	#4
Thomas Wright Senior Member Join Date: Jun 2008 Location: London Posts: 264	much obliged chaps, pity we'll have to send all the cameras back but good of red to do it free eh wot. (i threw the "eh wot" in for ed, i don't really talk like that)