blog about how to record sound on 5dmk2

[Dan Chung]

Chris,

Does your sign mixer output mic level output to the 5dmkII? and if so what is the quality like? Currently I'm having to PAD the output of my Sound Devices MixPre.

thanks

Dan

[Peter Chang]

Originally Posted by Dan Chung

Money no object I would have a Beachtek, a top of the line Sound Devices mixer coupled and a high end audio recorder.

Dan, If money were no object, which recorder would you go with?

[Dan Chung]

Money no object, probably this one The 788T Portable, Multi-Track Audio Recorder with Time Code | Sound Devices, LLC

Not exactly camera mountable though.

Dan

[Dan Chung]

FYI - the Beachtek is available to order now from here Beachtek | DXA-5D DUAL XLR ADPTR f/EOS 5D MII/48V | DXA-5D | B&H

Dan

[Jon Fairhurst]

Unfortunately, it seems that the Beachtek has passive audio circuitry, rather than a low noise active preamp. I assume that it would work okay for high-sensitivity mics, but for low-output mics, we'd have to turn up the gain on the 5D preamps (by turning down the pilot signal), which could lead to hiss.

Currently, with my AT815b, I'm not happy with the noise into the M-Audio MicroTrack II. I'd be surprised if the 5D preamps are any better.

I'm looking forward to reading some real-world tests before the Mark Free firmware makes the pilot tone solution obsolete...

[Dan Chung]

Jon,

You are correct about the Beachtek's passive audio circuitry but so far I've had a high level of success with the radio mics and Sanken CS-1 shotgun on the 5dmkII, using my older Beachtek DXA-6 and a 1khz tone generator.

5dmkII with 1khz tone real world demo on Vimeo

As you say I think careful mic matching will be essential, high sensitivity mics should be fine.

Dan

[Mike Demmers]

Originally Posted by Jon Fairhurst

Currently, with my AT815b, I'm not happy with the noise into the M-Audio MicroTrack II. I'd be surprised if the 5D preamps are any better.

Interesting - from the specs on both devices, the mic noise should predominate over the preamp noise.

However, looking more closely, I see the AT815b has a somewhat unusually high output impedance, and actually so does the MicroTrack (for a mic input).

I wonder if the AT815b is a transformer output mic? Somewhat skimpy specs do not say. If this were mine, I might try something like this:

Shure - A15BT Bridging Transformer

set to the 600:7500 position to get a better impedance match, more gain, and to improve the S/N by 6-10 db. Maybe even the higher gain setting would work.

Of course the battery would need to be used since a transformer will not pass the phantom power.

The A15BT Bridging Transformer is a pretty handy problem solver to have around for other uses as well.

Possibly the problem is not so much the preamp as that (maybe) the mic is designed to work into a different kind of load (a transformer).

Transformer input mic preamps used to be the norm in broadcast environments due to their superior noise cancellation.

I notice the new version of this mic now has a lower (and more common) output impedance.

Microphones are one of the few remaining places in audio where impedance matching is still important.

-Mike

[John Benton]

Originally Posted by Noa Put

Also the Zoom h4's are known for their problems that they can cause noticeable synching problems as their internal clock, or whatever you call it, does not run at the same speed as a camera. Something you'd have to fix before you take it into your editing software. Don't know if they fixed that with the new version but the Zacuto video didn't mention that at all, once you know the right procedure for it it takes about 5 minutes to get it right but I found it a bit dissapointing that it was not mentioned.

How does one sync the H2 with the canon 5D footage?
I have done a search on this forum and am still at a loss

[Jon Fairhurst]

Originally Posted by Mike Demmers

Interesting - from the specs on both devices, the mic noise should predominate over the preamp noise.

I've used the mic into my Mackie board and with a Panasonic GS500 though a transformer, and never had much problem with hiss (not that it was zero, but it is low enough to be swamped by ambient sounds. It wasn't hard to cover with background music, foley, etc.) Straight into the MicroTrack II, the hiss is horrible and requires noise reduction. This cost me way too much time in post, and the end result, while not bad, wasn't great either.

Anyway, I'm now of the mind that I want to feed my mic into a nice preamp, boost the signal, and feed it into the recorder/camera with minimal gain. I might change cameras and recorders over time, but a good battery-powered preamp can potentially outlast them all.

This approach nearly takes the camera/recorder preamp out of the equation. Of course, we're still left with the anti-aliasing filter, A/D quality, clock stability, bit depth, and possible encoding (if not PCM), so the recorder still matters. But in my experience, the camera/recorder preamp is the nail that it sticking up the furthest - by a lot.

[Jon Fairhurst]

Originally Posted by John Benton

How does one sync the H2 with the canon 5D footage?
I have done a search on this forum and am still at a loss

I've done it manually (with the MicroTrack II, rather than the H2, but it's similar.) Just match the H2 waveform with the waveform from the 5D's internal mic.

For Final Cut, there's some software that can help to this automatically, but I'm a Vegas user on a PC.

One problem is that the clock in the H2 isn't very accurate, so time can drift between the sources. On Vegas, I would sync up the sound at the start of a clip, and then stretch/squeeze the audio clip to sync up a sound at the end of the clip. In Vegas, you hold the CTRL key, grab the end of the audio clip and move it left or right, until the waveforms match. For short clips (like we do) this isn't needed. If you record a long speech, definitely sync both the start and the end.

BTW, sync doesn't need to be perfect. Anything within 10ms is excellent, and within 40ms is tolerable.

Also, I've tested the 5D for audio latency, and it looks to be sync'd nearly perfectly to the video. No compensation is needed on your part.

[Mike Demmers]

Originally Posted by Jon Fairhurst

Anyway, I'm now of the mind that I want to feed my mic into a nice preamp, boost the signal, and feed it into the recorder/camera with minimal gain. I might change cameras and recorders over time, but a good battery-powered preamp can potentially outlast them all.

Well, I would agree that is the best solution - the preamps in the Microtrack are not exactly the best.

I was just trying to figure out why that particular mic and preamp were getting along so very poorly.

I think it is a good example of the old Murphy's Law corollary about 'tolerances will always add - the same direction'. ;-)

-Mike

[Spiro Hernandez]

Originally Posted by Jon Fairhurst

Personally, I'm thinking of getting a Sound Devices MM-1 (one channel preamp with headphone output) or the MP-1 (without phone out). Street cost new is $350 or $300, respectively. I could then patch that into the 5D with a pilot tone in the other channel, or into most any recorder. So far, I haven't needed more than mono field audio anyway.

As long as you feed a nice, hot, clean signal to your recorder/camera, theoretically, the quality of the recorder isn't as important. It's kind of like using a cheap camera - they're terrible in low light, but can do a decent job with lots of light and good glass.

This is very interesting to me. I own the H4n, but have not been very impressed with the XLR quality. Yesterday I was using the Sony ECM-44B lav and I just couldn't get the levels high enough. I had to keep asking the interviewee to talk louder.

I don't know anything about these "preamp" devices. Would I use this with my H4n, and would it help boost the levels?

[Jon Fairhurst]

Originally Posted by Spiro Hernandez

I don't know anything about these "preamp" devices. Would I use this with my H4n, and would it help boost the levels?

That's exactly right. For instance, the juicedLink preamps have high, medium, and low gain settings, as well as a knob for each channel. Assuming that the circuit is clean (I receive mine tomorrow), you can boost the signal without adding any appreciable noise.

There are two approaches for the outputs. Some preamps put out line levels, and others put out mic levels, which are much lower. The juicedLink preamps have a mic/line switch, so it will work either way. [EDIT: The last sentence was incorrect. The mic/line switches are for the inputs, not the outputs. The output is always at mic level.] If you use a SoundDevices mixer, you would need to pad down the output when feeding a mic input (like on the 5D2.)

The juicedLink preamps target camcorders, so the output is a stereo 1/8-inch jack. It's not clear if the H4n's 1/8-inch input is stereo or not. You might need to get a 1/8-inch to dual 1/4" splitter. [EDIT: The H4n 1/8-inch mic inputs are indeed stereo. Just plug the juicedLink in directly.]

I plan to set mine up for two configurations: to the MicroTrackII and to the 5D2. The advantage of the Microtrack is that our audio guy can roam unplugged. For a long distance shoot, I could even have the talent carry the MicroTrackII and the preamp, rather than use a wireless connection. For one-person shoots, being able to connect directly to the 5D2 will be excellent.

Actually, the juicedLink will potentially let us use even cheaper recorders that don't have XLRs or phantom power features. Personally, I think the H4n and MicroTrackII are in a no-man's-land - sure they support XLR mics, but if they don't do it cleanly, they what's the point?

Anyway, I look forward to testing it. I'll post the results...

[Dan Brockett]

Jon:

H4N 3.5mm jack is stereo. I used it with my stereo Sony MCS-907 two weeks ago to record live music. Definitely stereo.

Dan

[Chris Barcellos]

Originally Posted by Dan Chung

Chris,
Does your sign mixer output mic level output to the 5dmkII? and if so what is the quality like? Currently I'm having to PAD the output of my Sound Devices MixPre.

thanks

Dan

Yes Dan, it does output at mic level. In fact we tried at lineblevel at one point and ended up creating some noise probably due to that issue