Confused about audio at concert at DVinfo.net

Diana Fisk · December 11th, 2015, 05:50 AM

Hi Everyone

I filmed a concert this evening and am a bit confused about the audio recording. I ran a L&R direct feed into my cameras (NX5's) and although my audio levels were fine (peaking at about 1/2 to 3/4) I thought I could hear slight distortion. I asked the audio guys if the feed I had could have a separate setting to what we could hear in the auditorium and he said no it was the same, so I put it down to bad headphones at the time. I have come home and checked it out and sure enough, even though the levels on the clips are only peaking to around -12db/-6db I can still hear a distortion.

Does anyone have any suggestions as to why this could be? I am filming another concert there tomorrow so hopefully will have this one sorted out a bit better.

Thanks in advance
Diana

Robert Benda · December 11th, 2015, 07:33 AM

Cameras, multiple?

And IF the auditorium sounded fine...

I'd want to know what the distortion sounds like. You keep mentioned about levels, so I'm presuming it sounds like that, rather than, say a hum or line noise of some kind.

Play the file using something that isn't your NLE. See if its still there.

If it is, there must have been a compressor or limiter between you and the feed.

Jeff Harper · December 11th, 2015, 08:03 AM

No explanation as to why, but I've had the same issue with direct feeds a couple of times also, I assume it's due to levels on the board being too high somewhere. I avoid using direct feeds as a result, but I don't do concerts either, just weddings. I put up voice recorders near speakers and it works fine for me.

Pete Cofrancesco · December 11th, 2015, 09:13 AM

It's a common problem. I put the board feed in one channel and shotgun ambient in the other. Often a digital recorder in another location. That way you have choices in case what you describe happens.

The board is giving you a line feed that is hotter than normal to drive speakers that are connected to long cable. It's like if you set your gear to mic level and you're receiving line. No matter how low you set the volume it will be distorted. They sell variable attenuaters that plug in line to the cable that might fix it.

Concerts are so loud you often can't hear problems until editing. Unfortunately you are the lowest priority of the board.

Robert Benda · December 11th, 2015, 09:24 AM

Pete has it right, I believe. I forgot to ask if you know what output, exactly, you used.

The board at a concert would be much better than mine, but there are different levels going out different outputs. Line, record, headphone, master, zone, and phono are all possible options.

Mine has two RCA outputs, Master and Record. Record out is exactly perfect for our needs.

zone, headphone, and phono are all potential problems.

/probably still missing options. Concert quality mixing boards are not my thing.
//taking an XLR output from a DJ's powered speaker could still result in distortion if the speaker sounds good. My speaker has another level knob for the speaker's output, so that the signal can be boosted again.

Diana Fisk · December 11th, 2015, 04:03 PM

It is definitely peaking rather than resulting in a hum or buzz - it is otherwise fine. It is mainly the really bass-y tracks that I am struggling with.

I have filmed at this venue multiple times without any issues so am a bit confused why it hasn't worked so well this time - it would make sense if the feed I had was set at a higher volume on their desk as to what we heard in the hall as I could hear that from a separate shotgun mic and that was fine.

Hmmmm I am worried about tonight now!!!

Josh Bass · December 12th, 2015, 06:36 AM

This is one of those situations where the REAL answer is "you need a separate sound guy." Someone whose specialty is sound and not someone trying to film a freaking concert and, "oh yeah, can you get perfect sound too while you're at it?"

This sound stuff is just as complicated as the video stuff, albeit maybe in different ways. I have been hosed by these situations as well. Without a sound pro who knows the ins and outs of line/mic/dbu/dbv -10/0/etc. etc. etc. you're always asking for trouble and praying for everything to work out.

Some -12 and -20 (maybe even -40 and -50) dB attenuators in your kit might be something to experiment with. If you can do tests beforehand where they feed you audio and you tweak based on that, that's helpful, although there's every chance in the world that whatever they feed you will somehow be different from the signals from the live recording because the world is awful and everything sucks all the time exactly when it needs not to.

Good luck.

-a guy who's been there.

Pete Cofrancesco · December 12th, 2015, 07:22 AM

Pretty much what Josh said. If it's that important this should be discussed with the client and sound people and tested before the day of the show.

Often the guys running the board only know how to use it for their purposes.

I show up early to test but often there isn't enough time to trouble shoot. Showing up and plugging in is leaving things to chance.

Robert Benda · December 13th, 2015, 07:55 AM

Quote:

Originally Posted by Pete Cofrancesco

Often the guys running the board only know how to use it for their purposes..

And too often, they don't even know that much. :)

Paul R Johnson · December 13th, 2015, 09:14 AM

Mix bus overload. If the concert is kind of hot on levels, it's quite common (especially on analogue mixers) to allow a little red light peaking on the channels - especially ones you know you will have a lot of problems getting them to sit well in the mix. The operator then has the majority of faders at their working level of maybe unity plus a little, and then the masters a little lower than they could be. the mix bus could be working well over the happy level, and with the output faders down low, the output meters looking normal. Everything connected to the mix buses gets the distortion, but in a busy mix it's often not that audible through the PA if the levels are loud. Your cameras may well get a nice within limits level, but the content screwed, quality wise. Desks with groups rather than VCAs often show the red lights and it's obvious, but cleverer desks that use VCAs mask the actual levels, because they're working at channel level.

Tim Paynter · December 13th, 2015, 01:25 PM

I learned not to trust the "official" mixer. I record wth at least one second device plus the camera (used mostly to sync). You have so little control over the sound guy that you are putting all of your cards in one basket, or one mixer. Best bring your own equipment and record your part on your own. Someone else mentioned the reason to have a soundman with good headphones on your team.

Paul R Johnson · December 13th, 2015, 01:38 PM

Current job - dictat arrives. MUST record show 3 for PRS - (UK music rights organisation) absolutely MUST be this show. So, give the sound operator a zoom and a couple of cables. Take out the tried and trusty HHB MD recorder to use as backup, never let me down, and then simply because I have to at some point, a locked of full width stage video - recording direct from the JVC to my macbook.

Zoom failed - data error. Later found to be cured by letting the zoom reformat the card.
MD failed - gobbledegook in the display, totally corrupt MD
Video - perfect, with good enough room sound for the purpose.

Never had backups for the backup, before but thank goodness I did it.

December 11th, 2015, 05:50 AM	#1
Diana Fisk Regular Crew Join Date: May 2013 Location: Melbourne, Australia Posts: 51	Confused about audio at concert Hi Everyone I filmed a concert this evening and am a bit confused about the audio recording. I ran a L&R direct feed into my cameras (NX5's) and although my audio levels were fine (peaking at about 1/2 to 3/4) I thought I could hear slight distortion. I asked the audio guys if the feed I had could have a separate setting to what we could hear in the auditorium and he said no it was the same, so I put it down to bad headphones at the time. I have come home and checked it out and sure enough, even though the levels on the clips are only peaking to around -12db/-6db I can still hear a distortion. Does anyone have any suggestions as to why this could be? I am filming another concert there tomorrow so hopefully will have this one sorted out a bit better. Thanks in advance Diana

December 11th, 2015, 07:33 AM	#2
Robert Benda Trustee Join Date: Dec 2012 Location: Crookston, MN Posts: 1,353	Re: Confused about audio at concert Cameras, multiple? And IF the auditorium sounded fine... I'd want to know what the distortion sounds like. You keep mentioned about levels, so I'm presuming it sounds like that, rather than, say a hum or line noise of some kind. Play the file using something that isn't your NLE. See if its still there. If it is, there must have been a compressor or limiter between you and the feed.

December 11th, 2015, 08:03 AM	#3
Jeff Harper Inner Circle Join Date: Jun 2005 Location: Cincinnati, OH Posts: 8,425	Re: Confused about audio at concert No explanation as to why, but I've had the same issue with direct feeds a couple of times also, I assume it's due to levels on the board being too high somewhere. I avoid using direct feeds as a result, but I don't do concerts either, just weddings. I put up voice recorders near speakers and it works fine for me. __________________ "The horror of what I saw on the timeline cannot be described."

December 11th, 2015, 09:13 AM	#4
Pete Cofrancesco Inner Circle Join Date: May 2004 Location: USA Posts: 3,005	Re: Confused about audio at concert It's a common problem. I put the board feed in one channel and shotgun ambient in the other. Often a digital recorder in another location. That way you have choices in case what you describe happens. The board is giving you a line feed that is hotter than normal to drive speakers that are connected to long cable. It's like if you set your gear to mic level and you're receiving line. No matter how low you set the volume it will be distorted. They sell variable attenuaters that plug in line to the cable that might fix it. Concerts are so loud you often can't hear problems until editing. Unfortunately you are the lowest priority of the board.

December 11th, 2015, 09:24 AM	#5
Robert Benda Trustee Join Date: Dec 2012 Location: Crookston, MN Posts: 1,353	Re: Confused about audio at concert Pete has it right, I believe. I forgot to ask if you know what output, exactly, you used. The board at a concert would be much better than mine, but there are different levels going out different outputs. Line, record, headphone, master, zone, and phono are all possible options. Mine has two RCA outputs, Master and Record. Record out is exactly perfect for our needs. zone, headphone, and phono are all potential problems. /probably still missing options. Concert quality mixing boards are not my thing. //taking an XLR output from a DJ's powered speaker could still result in distortion if the speaker sounds good. My speaker has another level knob for the speaker's output, so that the signal can be boosted again.

December 11th, 2015, 04:03 PM	#6
Diana Fisk Regular Crew Join Date: May 2013 Location: Melbourne, Australia Posts: 51	Re: Confused about audio at concert It is definitely peaking rather than resulting in a hum or buzz - it is otherwise fine. It is mainly the really bass-y tracks that I am struggling with. I have filmed at this venue multiple times without any issues so am a bit confused why it hasn't worked so well this time - it would make sense if the feed I had was set at a higher volume on their desk as to what we heard in the hall as I could hear that from a separate shotgun mic and that was fine. Hmmmm I am worried about tonight now!!!

December 12th, 2015, 06:36 AM	#7
Josh Bass Slash Rules! Join Date: Apr 2002 Location: Houston, Texas Posts: 5,472	Re: Confused about audio at concert This is one of those situations where the REAL answer is "you need a separate sound guy." Someone whose specialty is sound and not someone trying to film a freaking concert and, "oh yeah, can you get perfect sound too while you're at it?" This sound stuff is just as complicated as the video stuff, albeit maybe in different ways. I have been hosed by these situations as well. Without a sound pro who knows the ins and outs of line/mic/dbu/dbv -10/0/etc. etc. etc. you're always asking for trouble and praying for everything to work out. Some -12 and -20 (maybe even -40 and -50) dB attenuators in your kit might be something to experiment with. If you can do tests beforehand where they feed you audio and you tweak based on that, that's helpful, although there's every chance in the world that whatever they feed you will somehow be different from the signals from the live recording because the world is awful and everything sucks all the time exactly when it needs not to. Good luck. -a guy who's been there. __________________ The Bass' camerawork The Bass on IMDB

December 12th, 2015, 07:22 AM	#8
Pete Cofrancesco Inner Circle Join Date: May 2004 Location: USA Posts: 3,005	Re: Confused about audio at concert Pretty much what Josh said. If it's that important this should be discussed with the client and sound people and tested before the day of the show. Often the guys running the board only know how to use it for their purposes. I show up early to test but often there isn't enough time to trouble shoot. Showing up and plugging in is leaving things to chance. Last edited by Pete Cofrancesco; December 12th, 2015 at 08:01 AM.

December 13th, 2015, 09:14 AM	#10
Paul R Johnson Inner Circle Join Date: Nov 2005 Location: Lowestoft - UK Posts: 4,045	Re: Confused about audio at concert Mix bus overload. If the concert is kind of hot on levels, it's quite common (especially on analogue mixers) to allow a little red light peaking on the channels - especially ones you know you will have a lot of problems getting them to sit well in the mix. The operator then has the majority of faders at their working level of maybe unity plus a little, and then the masters a little lower than they could be. the mix bus could be working well over the happy level, and with the output faders down low, the output meters looking normal. Everything connected to the mix buses gets the distortion, but in a busy mix it's often not that audible through the PA if the levels are loud. Your cameras may well get a nice within limits level, but the content screwed, quality wise. Desks with groups rather than VCAs often show the red lights and it's obvious, but cleverer desks that use VCAs mask the actual levels, because they're working at channel level.

December 13th, 2015, 01:25 PM	#11
Tim Paynter Major Player Join Date: Mar 2014 Location: Denver Posts: 255	Re: Confused about audio at concert I learned not to trust the "official" mixer. I record wth at least one second device plus the camera (used mostly to sync). You have so little control over the sound guy that you are putting all of your cards in one basket, or one mixer. Best bring your own equipment and record your part on your own. Someone else mentioned the reason to have a soundman with good headphones on your team.

December 13th, 2015, 01:38 PM	#12
Paul R Johnson Inner Circle Join Date: Nov 2005 Location: Lowestoft - UK Posts: 4,045	Re: Confused about audio at concert Current job - dictat arrives. MUST record show 3 for PRS - (UK music rights organisation) absolutely MUST be this show. So, give the sound operator a zoom and a couple of cables. Take out the tried and trusty HHB MD recorder to use as backup, never let me down, and then simply because I have to at some point, a locked of full width stage video - recording direct from the JVC to my macbook. Zoom failed - data error. Later found to be cured by letting the zoom reformat the card. MD failed - gobbledegook in the display, totally corrupt MD Video - perfect, with good enough room sound for the purpose. Never had backups for the backup, before but thank goodness I did it.