HDV AUDIO Help at DVinfo.net

Gilbert Khoury · March 17th, 2006, 01:23 PM

Hello everyone,

I got my Canon XLH1 and I love it. I am planning to shoot a short film and I am planning to shoot in HDV. I have a Senheizer Microphone with an XLR plug as a boom microphone. I understand that I need a field mixer to get a proper sound. I understand if I use the regular mixers in the market $1200 dollars one I won't get an HD quality sound. I have just heard recently there is a new field mixer on the market for HDV recording and it cost around $15,000 dollars. That's quite a lot of money for me. I was wondering what's the cheapeast way to get an HDV sound (Maybe it is not called HDV sound I am not sure what's the technical term called but I need a high quality sound that goes with my HDV picture). I know I have an option to just plug the external boom to my camera without a mixer but the sound might not be of a high quality. Are there any other options than purchasing this $15,000 dollars field mixer?

Please help.

Regards,

Gilbert.

Robert Sanders · March 17th, 2006, 01:50 PM

I shot a project with the XL2 and I ran my ME66 Sennheiser directly into the XLR mic inputs. I set the attenuation to automatic and I got phenomenal results.

http://www.starwaypictures.com/day11

I'm sure the H1 will behave similarly. It's not PCM audio. It's MPEG audio at 192Kbps. For dialog, though. It should be fine.

Gilbert Khoury · March 17th, 2006, 02:18 PM

Thank you Robert for your response.

Cheers,

Gilbert.

Barlow Elton · March 17th, 2006, 02:24 PM

Just a correction: It's 192kbs per channel of audio. 384 kbs total. It sounds fine.

Gilbert Khoury · March 17th, 2006, 02:56 PM

Hello Robert,

Pardon my ignorance what's the attenuation for? Does the attenuation take care of adjusting the audio recording level? I am just wondering if the Canon XL2 and XLH1 take care of the audio why people still buy all these field mixers?

By the way, I checked your website and I watched the "Day 11" footage it looks cool. Did you shoot it in Xl2?

Thanks,

Gilbert.

A. J. deLange · March 17th, 2006, 03:27 PM

I think there is some confusion between "attenuation" and "AGC" (Automatic Gain Control). The XL cameras have the latter (AGC) but the attenuator must be switched in manually. The AGC, as the name implies, adjusts the gain of the audio system to, on the one hand, prevent overload when sound levels go up and, on the other hand, make sure some minimum level is recorded when sound is low. Purists don't use AGC any more than they use auto exposure but as we can't be tweaking iris, focus, zoom and audio levels at the same time many will set the AGC on. I'll note that my camera came out of the box with it off which caused me to record some distortion which I blamed on the compression algorithm. With AGC on things are just fine with the exception of the usual AGC induced problems mainly failure to reduce gain instantly when a loud noise occurs and to restore it the instant the loud noise subsides. Thus a pistol shot during a recording of the sounds of a quiet summer evening may have it's leading edge clipped. When it's over you will then hear the crickets level come up gradually back to where they were before the pistol shot. This is where a mixer comes in or rather the guy who works the mixer. His are the extra hands that the lone camera man does not have. He might well approach the problem by splitting the signal to two channels with gain separated by several dB. On the low gain channel the crickets won't be recorded at the optimum level but the pistol shot won't overload. On the other channel the pistol shot will clip but the crickets will be at the proper level except during the pistol shot. When the piece is edited the editor will switch between the two channels at the appropriate times.

More generally the mixer is useful when there are multiple microphones and when recording is to a device other than the camera such as a DAT recorder or a laptop. As these both record using PCM format one has no worries about compression artifacts, especially where 4 channels are required (and the laptop will allow recording more than 4 if it has enough power and the A/D enough channels). Remember that the XL-H1 emits time code so that a properly equipped mixer and A/D combination permits recording synchronously and tagged with time code. Of course a mixer can be used to present 4 channels to the inputs of the XL-H1 as well and one might want to do that if sources are multiple or if one wants the sound man's extra hands (and ears).

Finally, the attenuator on the camera is used to introduce a fixed gain reduction as when one is working with the gain controlled manually and the sound field is intense or when an external microphone is unusually "hot".

Daniel Epstein · March 17th, 2006, 03:37 PM

Gilbert,
You very likely do want a mixer to control the audio levels and have the boom operator monitor the sound. The Sound Devices 3 input mixer or the Wendt X3 sound very good. Shure FP-33 can do in a pinch. If you want the best sound recording you might want to double record to a deck with timecode like the Fostex FR 2, or Tascam to avoid the HDV compression of the sound. This is something you should talk to your sound man about since it does require some sophistication to set up the proper procedures for the shoot.
The actual HDV recording is quite clean but it is compressed more than DV so it works okay but could be improved with a seperate recording. You may find it is not worth the effort and money but I do recommend at least a mixer and headphones.

Gilbert Khoury · March 17th, 2006, 03:44 PM

Thank you A.J for the thorough explanation I appreciate it a lot. Now I understand more about audio. Here are my questions:

1) About the crickets example, if I use the boom without a mixer and capture the sound of the crickets will I be able to fix that in post (i.e. Apple Soundtrack Pro)?

2) What do you advise if I am using a boom Seinheizer microphone with my XLH1 what kind of mixer should I use that is reasonably priced?

3) You mentioned I can use my computer as a mixer is there a software I need to purchase?

Sorry I have so many questions.

A. J. deLange · March 17th, 2006, 04:05 PM

Gilbert,

1. Yes, you will be able to fix the situation to some extent but I'm not sure how effectively. FCP will let you key-frame the audio to level out the rising intensity as the AGC raises the gain and Soundtrack Pro has the capability to "fix" clipping. I've never had to use it so I don't know how effective it is. If you were going to do it this way I'd try using manual gain set low enough to keep the shot from clipping and then try boosting gain in FCP or SP after the shot. I have a good feel for what would be likely to happen if you did this with PCM but I don't when it comes to compressed audio.

2. I'll skip this one as there are others more experienced than I with the various available units. Personally I use a MOTU Traveller which is a portable combination mixer and A/D converter.

3. See 2. The MOTU system has both software and hardware components. As is often the case the hardware comes with minimum capability software and then they hit you up for the big bucks when you realize that you need fuller capability.

Don't apologize. Answering questions is what this list is here for.

Steve Rosen · March 17th, 2006, 05:08 PM

Another option, rather than buy an $800 mixer, is to shoot double sytem and record audio on the new Tascam HD-P2, which is around $1200. It has excellent audio quality, phantom power, XLRs, records on flash cards, has timecode and firewire.

Personally, being old school, I get hassled by trying to constantly jam-sync timecode or use a cable.. wireless TC is a distinct possibility, but I just use the old mike slate (soundman taps the mike) or blooper technique for sync, since I'm used to it. It means a little time spent syncing in post, but the audio is far superior.

Gilbert Khoury · March 18th, 2006, 12:09 AM

Thank you everybody for all the answers I appreciate it a lot!!!

Kristian Indrehus · March 18th, 2006, 01:53 AM

Quote:

Originally Posted by Steve Rosen

Another option, rather than buy an $800 mixer, is to shoot double system and record audio on the new Tascam HD-P2, which is around $1200.

There also is a very portable and less expensive option.
http://www.m-audio.com/products/en_u...2496-main.html

Micro Track is pocket size and records 24bit/96K. Phantom power and high quality pre-amps. No time-code, but as Steve points out manual syncing is easy.

Gilbert Khoury · March 18th, 2006, 06:07 AM

For the Fostex FR 2, or Tascam HD-P2 mixers what kind of HD boom microphone per se I need? Is there a model that you recommend (I know Senheinzer are good but which one has the HD capability)?

Kristian Indrehus · March 18th, 2006, 08:27 AM

Quote:

Originally Posted by Gilbert Khoury

For the Fostex FR 2, or Tascam HD-P2 mixers what kind of HD boom microphone per se I need? Is there a model that you recommend (I know Senheinzer are good but which one has the HD capability)?

There is no such thing as a HD microphone. Sennheizer is a good choice among many.

Steve Rosen · March 18th, 2006, 09:35 AM

I've had a Sennheiser 816 for over ten years. I paid $900 for it, not including shock mount and zeppelin. Might seem like a lot of money to some, but this is technology that doesn't become obsolete the minute you open the box - it's still state-of-the-art and has been used through five, count them, five camera updates.

I use an AT shotgun on the camera, it was around $400 and is pretty close to the 816. Since a nose mike gets more abuse, I wanted something rugged and more "replaceable".. It also has served me well for over 10 years.

Buy the best once - it's better than buying inferior products over and over again...

March 17th, 2006, 01:23 PM	#1
Gilbert Khoury Regular Crew Join Date: Jan 2006 Posts: 47	HDV AUDIO Help Hello everyone, I got my Canon XLH1 and I love it. I am planning to shoot a short film and I am planning to shoot in HDV. I have a Senheizer Microphone with an XLR plug as a boom microphone. I understand that I need a field mixer to get a proper sound. I understand if I use the regular mixers in the market $1200 dollars one I won't get an HD quality sound. I have just heard recently there is a new field mixer on the market for HDV recording and it cost around $15,000 dollars. That's quite a lot of money for me. I was wondering what's the cheapeast way to get an HDV sound (Maybe it is not called HDV sound I am not sure what's the technical term called but I need a high quality sound that goes with my HDV picture). I know I have an option to just plug the external boom to my camera without a mixer but the sound might not be of a high quality. Are there any other options than purchasing this $15,000 dollars field mixer? Please help. Regards, Gilbert.

March 17th, 2006, 01:50 PM	#2
Robert Sanders Starway Pictures Join Date: Jul 2005 Location: Studio City Posts: 581	I shot a project with the XL2 and I ran my ME66 Sennheiser directly into the XLR mic inputs. I set the attenuation to automatic and I got phenomenal results. http://www.starwaypictures.com/day11 I'm sure the H1 will behave similarly. It's not PCM audio. It's MPEG audio at 192Kbps. For dialog, though. It should be fine. __________________ http://www.starwaypictures.com http://starwaypictures.blogspot.com/

March 17th, 2006, 02:18 PM	#3
Gilbert Khoury Regular Crew Join Date: Jan 2006 Posts: 47	HDV Audio Help Thank you Robert for your response. Cheers, Gilbert.

March 18th, 2006, 12:09 AM	#11
Gilbert Khoury Regular Crew Join Date: Jan 2006 Posts: 47	Thank you Thank you everybody for all the answers I appreciate it a lot!!!

March 17th, 2006, 02:24 PM	#4
Barlow Elton Major Player Join Date: Mar 2005 Location: UT Posts: 945	Just a correction: It's 192kbs per channel of audio. 384 kbs total. It sounds fine.

March 17th, 2006, 02:56 PM	#5
Gilbert Khoury Regular Crew Join Date: Jan 2006 Posts: 47	Hello Robert, Pardon my ignorance what's the attenuation for? Does the attenuation take care of adjusting the audio recording level? I am just wondering if the Canon XL2 and XLH1 take care of the audio why people still buy all these field mixers? By the way, I checked your website and I watched the "Day 11" footage it looks cool. Did you shoot it in Xl2? Thanks, Gilbert.

March 17th, 2006, 03:27 PM	#6
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	I think there is some confusion between "attenuation" and "AGC" (Automatic Gain Control). The XL cameras have the latter (AGC) but the attenuator must be switched in manually. The AGC, as the name implies, adjusts the gain of the audio system to, on the one hand, prevent overload when sound levels go up and, on the other hand, make sure some minimum level is recorded when sound is low. Purists don't use AGC any more than they use auto exposure but as we can't be tweaking iris, focus, zoom and audio levels at the same time many will set the AGC on. I'll note that my camera came out of the box with it off which caused me to record some distortion which I blamed on the compression algorithm. With AGC on things are just fine with the exception of the usual AGC induced problems mainly failure to reduce gain instantly when a loud noise occurs and to restore it the instant the loud noise subsides. Thus a pistol shot during a recording of the sounds of a quiet summer evening may have it's leading edge clipped. When it's over you will then hear the crickets level come up gradually back to where they were before the pistol shot. This is where a mixer comes in or rather the guy who works the mixer. His are the extra hands that the lone camera man does not have. He might well approach the problem by splitting the signal to two channels with gain separated by several dB. On the low gain channel the crickets won't be recorded at the optimum level but the pistol shot won't overload. On the other channel the pistol shot will clip but the crickets will be at the proper level except during the pistol shot. When the piece is edited the editor will switch between the two channels at the appropriate times. More generally the mixer is useful when there are multiple microphones and when recording is to a device other than the camera such as a DAT recorder or a laptop. As these both record using PCM format one has no worries about compression artifacts, especially where 4 channels are required (and the laptop will allow recording more than 4 if it has enough power and the A/D enough channels). Remember that the XL-H1 emits time code so that a properly equipped mixer and A/D combination permits recording synchronously and tagged with time code. Of course a mixer can be used to present 4 channels to the inputs of the XL-H1 as well and one might want to do that if sources are multiple or if one wants the sound man's extra hands (and ears). Finally, the attenuator on the camera is used to introduce a fixed gain reduction as when one is working with the gain controlled manually and the sound field is intense or when an external microphone is unusually "hot".

March 17th, 2006, 03:37 PM	#7
Daniel Epstein Trustee Join Date: Jan 2006 Location: New York, NY Posts: 1,267	Gilbert, You very likely do want a mixer to control the audio levels and have the boom operator monitor the sound. The Sound Devices 3 input mixer or the Wendt X3 sound very good. Shure FP-33 can do in a pinch. If you want the best sound recording you might want to double record to a deck with timecode like the Fostex FR 2, or Tascam to avoid the HDV compression of the sound. This is something you should talk to your sound man about since it does require some sophistication to set up the proper procedures for the shoot. The actual HDV recording is quite clean but it is compressed more than DV so it works okay but could be improved with a seperate recording. You may find it is not worth the effort and money but I do recommend at least a mixer and headphones.

March 17th, 2006, 03:44 PM	#8
Gilbert Khoury Regular Crew Join Date: Jan 2006 Posts: 47	Thank you A.J for the thorough explanation I appreciate it a lot. Now I understand more about audio. Here are my questions: 1) About the crickets example, if I use the boom without a mixer and capture the sound of the crickets will I be able to fix that in post (i.e. Apple Soundtrack Pro)? 2) What do you advise if I am using a boom Seinheizer microphone with my XLH1 what kind of mixer should I use that is reasonably priced? 3) You mentioned I can use my computer as a mixer is there a software I need to purchase? Sorry I have so many questions.

March 17th, 2006, 04:05 PM	#9
A. J. deLange Major Player Join Date: Jun 2004 Location: McLean, VA United States Posts: 749	Gilbert, 1. Yes, you will be able to fix the situation to some extent but I'm not sure how effectively. FCP will let you key-frame the audio to level out the rising intensity as the AGC raises the gain and Soundtrack Pro has the capability to "fix" clipping. I've never had to use it so I don't know how effective it is. If you were going to do it this way I'd try using manual gain set low enough to keep the shot from clipping and then try boosting gain in FCP or SP after the shot. I have a good feel for what would be likely to happen if you did this with PCM but I don't when it comes to compressed audio. 2. I'll skip this one as there are others more experienced than I with the various available units. Personally I use a MOTU Traveller which is a portable combination mixer and A/D converter. 3. See 2. The MOTU system has both software and hardware components. As is often the case the hardware comes with minimum capability software and then they hit you up for the big bucks when you realize that you need fuller capability. Don't apologize. Answering questions is what this list is here for.

March 17th, 2006, 05:08 PM	#10
Steve Rosen Major Player Join Date: Dec 2005 Location: Monterey, California Posts: 895	Another option, rather than buy an $800 mixer, is to shoot double sytem and record audio on the new Tascam HD-P2, which is around $1200. It has excellent audio quality, phantom power, XLRs, records on flash cards, has timecode and firewire. Personally, being old school, I get hassled by trying to constantly jam-sync timecode or use a cable.. wireless TC is a distinct possibility, but I just use the old mike slate (soundman taps the mike) or blooper technique for sync, since I'm used to it. It means a little time spent syncing in post, but the audio is far superior.

March 18th, 2006, 06:07 AM	#13
Gilbert Khoury Regular Crew Join Date: Jan 2006 Posts: 47	For the Fostex FR 2, or Tascam HD-P2 mixers what kind of HD boom microphone per se I need? Is there a model that you recommend (I know Senheinzer are good but which one has the HD capability)?

March 18th, 2006, 09:35 AM	#15
Steve Rosen Major Player Join Date: Dec 2005 Location: Monterey, California Posts: 895	I've had a Sennheiser 816 for over ten years. I paid $900 for it, not including shock mount and zeppelin. Might seem like a lot of money to some, but this is technology that doesn't become obsolete the minute you open the box - it's still state-of-the-art and has been used through five, count them, five camera updates. I use an AT shotgun on the camera, it was around $400 and is pretty close to the 816. Since a nose mike gets more abuse, I wanted something rugged and more "replaceable".. It also has served me well for over 10 years. Buy the best once - it's better than buying inferior products over and over again...