Recording Broadcast-Quality Audio on the Canon 5D Mark II DSLR Camera

Posted by Scott in Resources, Video 06 Feb 2012

Despite its limitations as a video camera, the Canon 5D Mark II DSLR remains a popular choice for filmmaking and video production because of its superb image quality, small size and great selection of lenses.   Many accessories have been manufactured to address limitations such as focus and bracing.   In my opinion, however, the camera’s biggest issue is its near inability to directly record broadcast-quality audio.  After many trials and field tests, I have created an solution that enables the camera to directly record superb audio.

Here’s the set-up

At the heart of my set-up is the Sound Devices 302 3-channel audio mixer, at right, which has some of the best pre-amplifiers on the market.  The mixer provides three XLR audio inputs and a standard left and right XLR output.  From the mixer’s XLR outputs, I use a custom-made XLR to mini-1/8″ cable that plugs directly into the camera’s MIC input jack.

Custom made cable that connects the mixer’s XLR left/right output to the camera’s 1/8-inch mini stereo input.

To bypass the 5D’s pre-amps, I manually set the audio level in the camera menu to one step (or one “click”) above zero. See the image below.

Manual audio setting menu in 5D.

Although the mixer’s outputs are considered line-level, I reduced it by -12db, which is done through the 302′s custom set-up menu.  By reducing the output from the mixer and keeping the camera’s audio level set one click above off, I’m able to feed a clean signal into the camera and bypassing the noisy pre-amps.  The result is a very clean audio track that’s locked to the video.

Even with the adjustments, the audio coming into the camera from the mixer is still a bit too high.  To compensate,  make sure to keep my audio level averages down around -18db to allow for extra headroom, which is the difference between the highest signal level present and the highest point on the device before distortion occurs.

Because the audio being recorded directly into the camera cannot be monitored (there is no headphone jack on the camera), a back-up system is important.  The 302 mixer has a mini-XLR, stereo “tape” output that is the same as the regular XLR outputs.  This is perfect for the connecting a digital audio recorder.  I connect a Zoom H4n recorder using a 1/8″ mini stereo to mini XLR cable.

This set-up has worked for more than 300 hours of footage over three documentary projects.  But despite the success, it’s not perfect.  The 1/8″ mini connector can come loose from the camera.  Since there’s no way to monitor the actual camera audio, there’s no way to tell what’s being recorded so you won’t know there’s a problem until you can check the video files later.

Where’s the problem?

The problem lies in the camera’s audio pre-amplifiers.  Pre-amps amplify the incoming microphone-level audio signal to a line-level signal, which is much less noisy.  Professional quality pre-amps eliminate the signal noise.  Canon used lower-quality pre-amps in the 5D II so when a microphone is plugged directly into the camera’s “mic in” jack and the audio level (gain) is turned up, a distinct hiss is present.  For filmmaking and broadcast applications, this is unacceptable.

Many articles have been written about how to circumvent the camera’s noisy audio pre-amps by recording audio separately with a digital recorder and later syncing it with the video in an application such as PluralEyes.  I’ve used this method in the past and it works pretty well but now it’s an unnecessary step.

The key is to use a hardware solution to bypass the camera’s pre-amps.  I arrived at this setup after extensive testing with off-the-shelf audio solutions for the 5D.  While testing third-party devices from BeachTek and juicedLink, which boost the incoming audio signal, I realized that a standard audio mixer would do the same thing.  None of the devices on the market provided the noise-free audio at the quality I required for documentary film production.

Field Work

Most of my field work is either alone or with one other person.  To provide maximum flexibility, all the audio gear fits in my waist bag.  This way, I can work alone or in conjunction with a sound person. (There’s a diagram below that illustrates how I wirelessly connect to a professional sound person.)

In addition to the audio gear I’ve described above, I use a Sennheiser ME-64 microphone on top of the camera.  A Rycote “Softie” is mounted on the ME-64 to cut wind noise.  A coiled XLR to XLR mic cable runs from the camera-mounted microphone and into the channel one input on the mixer.  The two other mixer inputs are used for wireless microphones.  Sony MDR – 7506 are my preferred headphones because they sound good in various sound environments and are virtually indestructible.

Working on a short film about poverty in Fresno, California. (Photo by Diana Baldrica)

 

Initially, being tethered to my waist bag concerned me but now I’m completely comfortable having everything together in one place.  The ThinkTank bag is constructed with small openings to weave cables easily through the interior compartments so everything stays organized.

As you can see in the above photograph, I tend to use my waist bag for multiple purposes, such as a tripod platform to steady my handheld shots.

 Working with a sound person

The diagram below shows the technical set-up when working with a sound person.

Click here to view PDF version of this diagram. ©2010 by Brenda Chen – published with permission.

For an extended period in 2010, I had the pleasure of using this set-up while working with filmmaker/journalist Bob Sacha on a three-film project for the Open Society Foundations campaign to Stop Torture in Health Care.  All three films for the project were shot on the 5D using this set-up.  Because Bob and I had duplicate, identical gear, we were able to seamlessly alternate between shooting and collecting audio on a daily basis.

My set-up is a result of field-testing by a number of people including; Travis Fox, Bob Sacha and Roger Phenix.  This set-up would not be in existence without the generous loaning of brand new equipment by Rich Topham, Eric Perez and staff at Pro-Sound Services in New York.

 

 

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  • Adam

    Nice. You could look at one of these.
    http://splashaudio.co.nz/wordpress/2012/01/05/audio-interface-for-canon-5d-and-other-dslr-cameras/
    Ive been building them for using between a mixer and a 5D. Ive also been modifying 302 and MixPre mixers so that the tape output is -36dB. This is almost perfict for DSLR cameras

    • Anonymous

      Adam,

      Thanks for the link.  

      My only concern is that feeding mic-level into the 5D means using the noisy preamps.  With the above set-up, the stronger signal allows me bypass the preamps.

      I’m anxious to test the new 5D Mark III to see if Canon used better preamps.

      Scott

      • Adam

        HI
        The box isolates the XLR’s and pads the level down to about -36dB. The level on the 5D is about 3 clicks up. Basicly does the same as your set up but un-balances the signal.

        Adam

        • Anonymous

          Got it.  Nice.  Thanks again for passing this along.

          Scott

  • Audio Warrior!

    What a load of tosh. A little knowledge can be a dangerous thing and you certainly have little knowledge about broadcast sound! Please stop! You’re hurting my ears!

    • Anonymous

      Audio Warrior,

      Please feel free to participate in the conversation with actual information.  We are all working to be better at what we do so if you have something to contribute, do so in a way that is helpful.

      Thank you.

      Scott

      • Audio Warrior!

        The information you are providing is not actual either. Broadcast audio is uncompressed 24bit, 48-192khz. I seriously doubt the 5D camera is capable of anything like this. Please prove me wrong. It is good for taking pictures, lets leave it at that. What you are contributing to here is really an old wives tale. File under nonsense. Don’t feel hurt by this Scott, lets call a spade a spade, and broadcast sound this is not. It is however a good guide for all those wedding video enthusiasts out there.

        • Anonymous

          I don’t specifically define “broadcast quality” in my post but I am referring to audio that meets the quality standards of the world’s top broadcasters such as PBS and the BBC as well as many feature documentary post-production facilities. With the 2.0.4 firmware installed, the 5D II records audio in 16-bit, 48kHz, a standard found in cameras ranging up to the $80,000 Sony HDW-F900 CineAlta.  

          I am not one to judge the quality of a device by numbers alone.  For me, the 5D II has worked very well.  The footage from this camera, although compressed, looks amazing in a theater and sounds great.

          Scott

        • Adam

          HI
          I understand what your saying Warrior. “Broadcast Quality” is a very loose term these days. 

          I’ve dun some detailed tests on the 5D audio and would describe the sound as “adequate”. When  the input is set up properly the noise floor is about -76dB. The low cut starts rolling off at 180Hz. NOt great but ok.

          The real week point is the mini jack and the lack of monitoring. Ive worked with quite a few Canon DSLR’s and have noticed that the mini jacks range from so tight you have to push hard to get the jack in to so loose your worried about it falling out. 

          The 5D does 48KHz 16bit sound. Just like a Sony EX or F3 camera. And Ive lost count of the times that Ive seen XD cameras with there sound set to 16bit.

          Having said all this. I always  record to cards.

          Adam

      • heiner kruse

        i initially tried it exactly the same way as you did.
        i still think there is a bit too much noise arriving using this method – as you have to turn the mixer to -18 which means the mixer signal (including the mixers noise) still gets amplified from the canon and the result is too much noise. do new firmware updates make changes or is magic lantern a serious help in your opinion?

  • http://www.timmatsui.com/ Tim Matsui

    Thanks Scott! I was just getting frustrated (again) with the cumbersome, cobbled-together nature of HDSLR video and sound. While I’m not going to run out and buy the 302 tomorrow, it does give me food for thought.

    • Anonymous

      Hey Tim.  You’re welcome.  Happy to try and help.  Drop me a note if you need more specific info.  Thanks!

      Scott

  • Elliottsphoto

    Hi Scott, This is exactly what I have been doing. I use an Azden 4 channel mixer. I find the 1/8″ phono cable to the DSLR is a little over driven.  I got a stereo XLR to 1/8″ phono adapter cable like the one you are using but it seems to cancel out the audio at the camera.  Where did you get your audio cable you used to attach your mixer to the camera?  I would like to get one.  It looks to be of good quality.

    • Jessica

      Hello Scott,

      I would also like to know where you purchased the XLR left/right to 1/8-inch mini stereo input cable. Thank you!

  • http://www.providentpartners.net/blog Albert_Maruggi

    this is all well and good, quite frankly it is outstandingly creative. Having said that the image quality must be so much better than say a Canon xa20 which is what I’m considering. Is it? I’m shooting a lot of sports, perhaps you are not shooting fast paced subjects and so the flexibility of the different lens is worth the work on the audio. The xa20 has two XLR inputs.

    I’m considering the Panasonic GH3 vs the Canon xa20, Since I’m a news video shooter i have not used DSLRs ever. So my concern is getting used to different zoom configuration on the DSLR. thanks for your thoughts.

  • Ivan Weiss

    Hey Scott, thanks for this post. I know you posted it a while back, and I was wondering if you had updated your setup since then. Also, what was the difference in sound quality between the sound recorded on the 5D and the backup audio on the H4N? Thanks again!

    • scottanger

      Hi Ivan, you’re welcome. No, I haven’t updated this system because a lot of my shooting is now on the Canon C300. When I use the 5D MKII, I still use this system.

      I haven’t noticed difference in audio quality between the audio recorded into the 5D using this system and the back-up on the H4N. Both sound great.

      Hope this helps.

      Cheers,

      Scott

  • Christof Elsinghorst

    Thank you.
    I bought a SD302 with a professional custom made 8meter multicable/snake containing left and right female xlr to male XLR’s and male stereo mini-jack to male stereo mini-jack (from camera headphones output to sd302 RTN input)
    That multicable was made for TVcamera’s with balanced XLR input, and minijack output

    female xlr ———-> (male multiconnector female multiconnector) —-> male XLR
    female xlr ———–> male multiconnector female multiconnector —-> male XLR
    stereo minijack –> (male multiconnector female multiconnector) —-> stereo minijack

    I want to use that multi cable for our canon 5d, so i’ve to make a cable like yours.
    2xFemaleXLR to mini-jack.

    Can you tell/show me the wiring diagram.
    I need to know which pins are connected.

    • scottanger

      Hi Christof,

      Thanks for writing. I worked with engineers at Pro Sound (http://www.pro-sound.com/) in New York to design the cables so they did all the wiring. I presented them with the problem and we worked together to solve it. I don’t know the wiring details. Sorry I can’t be more helpful. There are a couple of sites I found via Google but I’d hate to pass along untested information. Any audio engineer should be able to help.

      Cheers,

      Scott

  • James B

    Thanks. Have you tried the new Zoom H6 direct into the 5D? My understanding is that it provides a much cleaner signal than the H4N.

    • scottanger

      James,

      No, I haven’t tried the new H6 yet because I’ve been shooting recent projects on the Canon C300. I’ve heard good things about the H6 as well. I would love to test it because I’m planning to use my audio set-up with a GoPro for an upcoming project.

      Please keep me posted if you use an H6. It would be great to hear your thoughts on the usability and quality.

      Cheers,

      Scott