Canon 5D Mark II Audio Exposed; with BeachTek DXA-5D and juicedLink CX231

Jon Fairhurst · June 25th, 2009, 05:47 PM

I should have the full video up some time this weekend. But here's the short story: both the H4n and juicedLink/5D2-ML are quite good. The H4n let's you separate it from the camera. The JL/5D2-ML is tethered (if not wireless), but you don't have to worry about sync.

If I'm filming somebody across a canyon with a 600mm lens on a 2x extender, give me the H4n. If I need to get the story on tonight's news broadcast - or to the 48-hour film festival judges on time - give me the juicedLink and Magic Lantern.

But this weekend, I should be able to provide a video and wave files for critical listening.

Jon Fairhurst · June 29th, 2009, 02:13 AM

1. Canon 5D Mark II Audio Exposed - Boom Mic (juicedLink, Zoom H4n, Microtrack II, BeachTek) on Vimeo

In Part 1 of Canon 5D Mark II Audio Exposed, I compare the Microtrack II, Zoom H4n, BeachTek DXA-5D, and the juicedLink CX 231 when recording a closely placed shotgun mic.

The only processing of the comparison audio was changing gain to match levels. You can download the uncompressed comparison audio here: http://p3pictures.com/audio_5d2/Audi...Part1_Boom.zip

Pending...
Part 2: Camera Mounted Mic
Part 3: Wireless Lavalier
Part 4: Foley
Part 5: Noise Tests and Final Conclusions

Enjoy!

Jon Fairhurst · June 29th, 2009, 12:00 PM

One thing I should point out is that I used 0dB analog gain in the Magic Lantern firmware. When using this with the Beachtek, I had to boost the heck out of it in post, leading to all that noise. Previous tests with 10 dB analog gain and 12 dB digital gain in camera gave better results with the BeachTek, but it was still on the noisy side. Also, the BeachTek was in mono mode for this test. It's possible that it's cleaner in stereo with the signal going just to one channel.

But the real challenge will come in part 2 with the camera mounted setup.

Again, here's part 1...
1. Canon 5D Mark II Audio Exposed - Boom Mic (juicedLink, Zoom H4n, Microtrack II, BeachTek) on Vimeo

Tramm Hudson · June 29th, 2009, 12:14 PM

Quote:

Originally Posted by Jon Fairhurst

One thing I should point out is that I used 0dB analog gain in the Magic Lantern firmware. When using this with the Beachtek, I had to boost the heck out of it in post, leading to all that noise. Previous tests with 10 dB analog gain and 12 dB digital gain in camera gave better results with the BeachTek, but it was still on the noisy side. Also, the BeachTek was in mono mode for this test. It's possible that it's cleaner in stereo with the signal going just to one channel.

I might be mis-hearing things, but it seems to me that the previous test with the Beachtek straight into the 5D had much more noise than this version. The Magic Lantern versions sounded about the same. The spectragraph of the initial test sure looked noisier:

Jon Fairhurst · June 29th, 2009, 02:15 PM

Hi Tramm,

On this test I used the Sennheiser ME-80, which is a much hotter mic than my Audio Technica AT815b. That means that I didn't need to boost the gain as much on this run. The juicedLink sounds clean anyway, so you don't notice the lower gain/noise. The BeachTek benefits highly from the hotter signal.

The next test is the On-Camera setup with the Audio Technica at five feet. That will be a much tougher test...

Chris Barcellos · June 29th, 2009, 08:47 PM

Quote:

Originally Posted by Jon Fairhurst

Hi Tramm,

On this test I used the Sennheiser ME-80, which is a much hotter mic than my Audio Technica AT815b. That means that I didn't need to boost the gain as much on this run. The juicedLink sounds clean anyway, so you don't notice the lower gain/noise. The BeachTek benefits highly from the hotter signal.

The next test is the On-Camera setup with the Audio Technica at five feet. That will be a much tougher test...

Jon: On the Beachtek, is there a volume control for the pilot tone. By my experience, a difference in the pilot tone level going into camera, will make a difference as to what is coming out. I would think Beachtek would have allowed for a variable sound.

I think what these test are showing, and what my testing is showing, is that with Magic Lantern, we will have a wide variety of choice to lay decent sound into our cameras.

Juiced link will be a prime tool in that process especially in the one or two man crew situation, but we will absolutely need Magic Lantern to be selectable to raise and lower camera gain depending on the tool being used, and the shooting situation.

Jon Fairhurst · June 30th, 2009, 01:28 AM

2. Canon 5D Mark II Audio Exposed - On Camera (juicedLink, Zoom H4n, Microtrack II, BeachTek) on Vimeo

In Part 2 of Canon 5D Mark II Audio Exposed, I compare the Microtrack II, Zoom H4n, BeachTek DXA-5D, and the juicedLink CX 231 when recording a camera-mounted long shotgun mic at five feet.

The only processing of the comparison audio was changing gain to match levels. You can download the uncompressed comparison audio here: http://p3pictures.com/audio_5d2/Audi...2_OnCamera.zip

Don't miss...
Part 1. Canon 5D Mark II Audio Exposed - Boom Mic (juicedLink, Zoom H4n, Microtrack II, BeachTek) on Vimeo
...
Part 3: Wireless Lavalier (pending)
Part 4: Foley (pending)
Part 5: Noise Tests and Final Conclusions (pending)

Jeremy Nicholl · June 30th, 2009, 01:48 AM

Quote:

Originally Posted by Jon Fairhurst

2. Canon 5D Mark II Audio Exposed - On Camera (juicedLink, Zoom H4n, Microtrack II, BeachTek) on Vimeo

In Part 2 of Canon 5D Mark II Audio Exposed, I compare the Microtrack II, Zoom H4n, BeachTek DXA-5D, and the juicedLink CX 231 when recording a camera-mounted long shotgun mic at five feet.

The only processing of the comparison audio was changing gain to match levels. You can download the uncompressed comparison audio here: http://p3pictures.com/audio_5d2/Audi...2_OnCamera.zip

There seems to be a problem with the zip file. I've downloaded twice, but neither Apple Unarchiver or Stuffit Expander can open it. Stuffit is claiming the file may be damaged.

Jon Fairhurst · June 30th, 2009, 09:05 AM

The uploads are now complete and tested. Enjoy!

Tramm Hudson · June 30th, 2009, 12:35 PM

Quote:

Originally Posted by Jon Fairhurst

The uploads are now complete and tested. Enjoy!

I analyzed the WAV file in the free Sonic Visualiser tool and it is quite striking the difference in noise levels. The darker/bluer the image, the lower the "hiss" and noise. My thoughts on the five tests:

* The Microtrak2 must have some sort of problem to produce so much noise at some harmonic.

* The Zoom sounds very clean.

* The pilot tone on the Beachtek is quite visible (the bright horizontal line). The hiss is also quite apparent (the bright background color).

* With the pilot tone turned off and using the Magic Lantern firmware the hiss is still very apparent.

* The juicedLink + Magic Lantern certainly sounds good and the spectragram shows the least noise. The only negative point is that there does seem to be a very faint inaudible (to me) harmonic up around 20.5 kHz.

Not having to deal with two-system audio will be such a relief! Thanks for running all of these tests, Jon.

Jon Fairhurst · June 30th, 2009, 12:40 PM

One thing to look for in this video is the motion of the bushes in the background. The mic was only about 10 feet from them. Sometimes the bushes are moving about, yet there is little or no wind noise. With other setups, there's no motion at all, but the wind noise is high.

My mic has a low cut switch which I left off purposefully for the test. (I turned the filter on for the narrator bits and EQ'd to make up for the thinner sound.)

One thing I'm not sure of is if the Zoom's low-cut filter is digital or analog. If it's digital, it won't stop the wind from overloading the A/D converters. You really need the low-cut to be in the analog domain, such as on the mic.

Chris Barcellos · June 30th, 2009, 05:50 PM

Jon:

Thanks for another very informative test !

Jon Fairhurst · June 30th, 2009, 06:36 PM

Chris,

You're welcome!

Tramm,

The visual representation is really telling. The Zoom sounds much quieter than the BeachTek into the ML firmware, but both show a purple background. Looking closely at the BeachTek, the signal is weaker at high frequencies, so the noise might be similar, but the signal to noise is lower.

The JL/ML plot looks amazing. I'd love to test it against a Sound Devices mixer/recorder.

Dan Chung · July 1st, 2009, 06:43 AM

John,

I've been testing the Sound Devices MixPre and Magic Lantern, along with the Juicedlink and the Beachtek. I think the biggest issue for S/N here is the amount of attenuation you put onto the XLR out of the mixer and what level you set in Magic Lantern. I'm currently using a -45db PAD and the level from the Sound Devices needs boosting a little in the camera, I'm assuming a lower value PAD will yield a better result but I have no way to test it.

Also has anyone noticed that the level meters in Magic Lantern pump when being fed a constant tone (1khz) from either a mixer or a tone generator into the Juicedlink. Not sure what's going on there??

Dan

Tramm Hudson · July 1st, 2009, 08:07 AM

Quote:

Originally Posted by Dan Chung

Also has anyone noticed that the level meters in Magic Lantern pump when being fed a constant tone (1khz) from either a mixer or a tone generator into the Juicedlink. Not sure what's going on there?

It is likely due to bad sampling in my code leading to aliasing. My audio level task samples every few ms and does a very simple moving weighted average. I noticed that Canon appears to vary the time between samples to try to avoid this problem.

In regards to the first few seconds of audio being messed up, that is due to Canon's mvr_rec_start() function re-writing the audio registers to their parameters. The task in 0.1.4 re-writes them at 1 Hz, but I have figured out how to register a property handler to get notified when recording starts so that I can re-write them only when necessary.

I'm also working on disabling the power save functions so that the camera won't turn off when Magic Lantern is running. And a config file with gains and zebra levels/enable. Also hdmi output support, slow contrast edge detection and headphone volume control. Coming soon in 0.1.5!

June 25th, 2009, 05:47 PM	#31
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	I should have the full video up some time this weekend. But here's the short story: both the H4n and juicedLink/5D2-ML are quite good. The H4n let's you separate it from the camera. The JL/5D2-ML is tethered (if not wireless), but you don't have to worry about sync. If I'm filming somebody across a canyon with a 600mm lens on a 2x extender, give me the H4n. If I need to get the story on tonight's news broadcast - or to the 48-hour film festival judges on time - give me the juicedLink and Magic Lantern. But this weekend, I should be able to provide a video and wave files for critical listening. __________________ Jon Fairhurst

June 29th, 2009, 02:13 AM	#32
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	Part 1 uploaded!!! 1. Canon 5D Mark II Audio Exposed - Boom Mic (juicedLink, Zoom H4n, Microtrack II, BeachTek) on Vimeo In Part 1 of Canon 5D Mark II Audio Exposed, I compare the Microtrack II, Zoom H4n, BeachTek DXA-5D, and the juicedLink CX 231 when recording a closely placed shotgun mic. The only processing of the comparison audio was changing gain to match levels. You can download the uncompressed comparison audio here: http://p3pictures.com/audio_5d2/Audi...Part1_Boom.zip Pending... Part 2: Camera Mounted Mic Part 3: Wireless Lavalier Part 4: Foley Part 5: Noise Tests and Final Conclusions Enjoy! __________________ Jon Fairhurst

June 29th, 2009, 12:00 PM	#33
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	One thing I should point out is that I used 0dB analog gain in the Magic Lantern firmware. When using this with the Beachtek, I had to boost the heck out of it in post, leading to all that noise. Previous tests with 10 dB analog gain and 12 dB digital gain in camera gave better results with the BeachTek, but it was still on the noisy side. Also, the BeachTek was in mono mode for this test. It's possible that it's cleaner in stereo with the signal going just to one channel. But the real challenge will come in part 2 with the camera mounted setup. Again, here's part 1... 1. Canon 5D Mark II Audio Exposed - Boom Mic (juicedLink, Zoom H4n, Microtrack II, BeachTek) on Vimeo __________________ Jon Fairhurst

June 29th, 2009, 02:15 PM	#35
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	Hi Tramm, On this test I used the Sennheiser ME-80, which is a much hotter mic than my Audio Technica AT815b. That means that I didn't need to boost the gain as much on this run. The juicedLink sounds clean anyway, so you don't notice the lower gain/noise. The BeachTek benefits highly from the hotter signal. The next test is the On-Camera setup with the Audio Technica at five feet. That will be a much tougher test... __________________ Jon Fairhurst

June 30th, 2009, 01:28 AM	#37
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	Part 2 uploading 2. Canon 5D Mark II Audio Exposed - On Camera (juicedLink, Zoom H4n, Microtrack II, BeachTek) on Vimeo In Part 2 of Canon 5D Mark II Audio Exposed, I compare the Microtrack II, Zoom H4n, BeachTek DXA-5D, and the juicedLink CX 231 when recording a camera-mounted long shotgun mic at five feet. The only processing of the comparison audio was changing gain to match levels. You can download the uncompressed comparison audio here: http://p3pictures.com/audio_5d2/Audi...2_OnCamera.zip Don't miss... Part 1. Canon 5D Mark II Audio Exposed - Boom Mic (juicedLink, Zoom H4n, Microtrack II, BeachTek) on Vimeo ... Part 3: Wireless Lavalier (pending) Part 4: Foley (pending) Part 5: Noise Tests and Final Conclusions (pending) __________________ Jon Fairhurst

June 30th, 2009, 09:05 AM	#39
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	Uploads Complete! The uploads are now complete and tested. Enjoy! __________________ Jon Fairhurst Last edited by Jon Fairhurst; June 30th, 2009 at 10:24 AM.

June 30th, 2009, 12:40 PM	#41
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	One thing to look for in this video is the motion of the bushes in the background. The mic was only about 10 feet from them. Sometimes the bushes are moving about, yet there is little or no wind noise. With other setups, there's no motion at all, but the wind noise is high. My mic has a low cut switch which I left off purposefully for the test. (I turned the filter on for the narrator bits and EQ'd to make up for the thinner sound.) One thing I'm not sure of is if the Zoom's low-cut filter is digital or analog. If it's digital, it won't stop the wind from overloading the A/D converters. You really need the low-cut to be in the analog domain, such as on the mic. __________________ Jon Fairhurst

June 30th, 2009, 05:50 PM	#42
Chris Barcellos Inner Circle Join Date: Nov 2005 Location: Elk Grove CA Posts: 6,838	Jon: Thanks for another very informative test ! __________________ Chris J. Barcellos

June 30th, 2009, 06:36 PM	#43
Jon Fairhurst Inner Circle Join Date: May 2006 Location: Camas, WA, USA Posts: 5,513	Chris, You're welcome! Tramm, The visual representation is really telling. The Zoom sounds much quieter than the BeachTek into the ML firmware, but both show a purple background. Looking closely at the BeachTek, the signal is weaker at high frequencies, so the noise might be similar, but the signal to noise is lower. The JL/ML plot looks amazing. I'd love to test it against a Sound Devices mixer/recorder. __________________ Jon Fairhurst

July 1st, 2009, 06:43 AM	#44
Dan Chung Major Player Join Date: Apr 2008 Location: Beijing Posts: 665	John, I've been testing the Sound Devices MixPre and Magic Lantern, along with the Juicedlink and the Beachtek. I think the biggest issue for S/N here is the amount of attenuation you put onto the XLR out of the mixer and what level you set in Magic Lantern. I'm currently using a -45db PAD and the level from the Sound Devices needs boosting a little in the camera, I'm assuming a lower value PAD will yield a better result but I have no way to test it. Also has anyone noticed that the level meters in Magic Lantern pump when being fed a constant tone (1khz) from either a mixer or a tone generator into the Juicedlink. Not sure what's going on there?? Dan