Turn off Audio Auto Level Control? at DVinfo.net

Peter Rush · July 14th, 2015, 09:52 AM

With my EA50 I could fall back on my camera shotgun mic in an emergency but I'm finding the audio from the A7 dire! I'm using the Rode videomic and when I was filming some speeches recently the camera is constantly pushing the gain in quiet moments - sounds really bad and pretty much unusable but for getting my audio recorders in sync

Canon 5d has manual levels - surely Sony haven't dropped the ball on this £2K camera? Manual recording levels is a pretty basic function of film making and is a hell of an omission - or am I missing something? You can set recording levels manually on the A7s but there seems still to be agc that can't be turned off

This review says there is no AGC but I can hear it on my recording kicking in when it goes quiet - what gives?

http://www.videomaker.com/article/17...-camera-review

Matt Sharp · July 14th, 2015, 01:03 PM

I believe the A7S has some AGC going on to limit the peaks, similar to the Sony UWP-D radio mics. I'd wager a guess that the example had the audio set high, and that the camera was limiting the highs and then falling back to the set level for the lows.

I'm not sure if the newest videomics still do it, but the older ones had 0, +10, and +20 db settings to somewhat defeat AGC.

Dave Sperling · July 14th, 2015, 03:43 PM

I've had good luck with interviews using a little two-channel Sound Devices Mix Pre to set my mic levels, coming out of the 1/8" 'tape out' connector on the mixer with an eighth inch stereo extension cable, then using a short eighth inch line-to-mic attenuator cable and keeping the camera volume set in the 10-14 range. Have gotten quality audio on the A7s this way - and it doesn't tie up the Mix Pre's primary outputs (in case they're needed to send audio to another camera.)

Chris Harding · July 14th, 2015, 09:06 PM

Hi Pete

I think most, if not all cameras nowdays don't have any AGC at all except as Matt says to stop clipping, You can be pretty sure that if it has a manual level control then it won't have AGC expect to limit peaks which it sounds like it's doing so, overall, you manual levels are simply too high and you are breaking into peaks which the limiter is using AGC for. In the old camcorder days there was no level control and AGC did the job from zero to max for you and you used to get that annoying gain increase when there was silence. I think Matt is right here and you simply need to turn down the manual level ..remember the Rode VideoMic has quite a "hot" output compared to other shotguns!! Why not test this out at home in a really quiet room? Stick on a pair of headphones and do some loud talking and then keep totally quiet and see what the base sound level is like? Then turn levels down on the camera and see if it does the same thing?

I would also try the same thing with a lav mic and see what happens .. the rode just might need to be limited a bit ..check the limiter on the Rode too

Chris

July 14th, 2015, 09:52 AM	#1
Peter Rush Inner Circle Join Date: Nov 2008 Location: UK/Yorkshire Posts: 2,069	Turn off Audio Auto Level Control? With my EA50 I could fall back on my camera shotgun mic in an emergency but I'm finding the audio from the A7 dire! I'm using the Rode videomic and when I was filming some speeches recently the camera is constantly pushing the gain in quiet moments - sounds really bad and pretty much unusable but for getting my audio recorders in sync Canon 5d has manual levels - surely Sony haven't dropped the ball on this £2K camera? Manual recording levels is a pretty basic function of film making and is a hell of an omission - or am I missing something? You can set recording levels manually on the A7s but there seems still to be agc that can't be turned off This review says there is no AGC but I can hear it on my recording kicking in when it goes quiet - what gives? http://www.videomaker.com/article/17...-camera-review Last edited by Peter Rush; July 14th, 2015 at 10:48 AM.

July 14th, 2015, 01:03 PM	#2
Matt Sharp Major Player Join Date: Nov 2010 Location: Northridge, CA Posts: 280	Re: Turn off Audio Auto Level Control? I believe the A7S has some AGC going on to limit the peaks, similar to the Sony UWP-D radio mics. I'd wager a guess that the example had the audio set high, and that the camera was limiting the highs and then falling back to the set level for the lows. I'm not sure if the newest videomics still do it, but the older ones had 0, +10, and +20 db settings to somewhat defeat AGC.

July 14th, 2015, 03:43 PM	#3
Dave Sperling Major Player Join Date: Jan 2010 Location: Tinton Falls, NJ Posts: 780	Re: Turn off Audio Auto Level Control? I've had good luck with interviews using a little two-channel Sound Devices Mix Pre to set my mic levels, coming out of the 1/8" 'tape out' connector on the mixer with an eighth inch stereo extension cable, then using a short eighth inch line-to-mic attenuator cable and keeping the camera volume set in the 10-14 range. Have gotten quality audio on the A7s this way - and it doesn't tie up the Mix Pre's primary outputs (in case they're needed to send audio to another camera.)

July 14th, 2015, 09:06 PM	#4
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Re: Turn off Audio Auto Level Control? Hi Pete I think most, if not all cameras nowdays don't have any AGC at all except as Matt says to stop clipping, You can be pretty sure that if it has a manual level control then it won't have AGC expect to limit peaks which it sounds like it's doing so, overall, you manual levels are simply too high and you are breaking into peaks which the limiter is using AGC for. In the old camcorder days there was no level control and AGC did the job from zero to max for you and you used to get that annoying gain increase when there was silence. I think Matt is right here and you simply need to turn down the manual level ..remember the Rode VideoMic has quite a "hot" output compared to other shotguns!! Why not test this out at home in a really quiet room? Stick on a pair of headphones and do some loud talking and then keep totally quiet and see what the base sound level is like? Then turn levels down on the camera and see if it does the same thing? I would also try the same thing with a lav mic and see what happens .. the rode just might need to be limited a bit ..check the limiter on the Rode too Chris