How do u all usually work with 7D sound?


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VeeDeoMan

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Hello everyone,

Want to find out more about the different styles of working with 7D or 5D sound recording?

To begin, i use 302 mixer, then output line level to record into my H2.
Pls share how you all do sound recording so we can learn from one another.
 

try a H4N instead. its much better . than sync in post.
 

I guess for most people, as long as there is sound, they're happy, but if we're to be anal about our sound quality, we should be more aware of how our audio signal path flows.

Both method of recordings are valid solutions, but I would think that Videoman's solution is a better one.....Firstly, his Sound Devices 302's microphone pre-amps is a lot cleaner than the H4n. By using line level signal to feed into the H2 recorder, he's definitely getting a cleaner audio signal into the H2. As such, he could probably record a much 'clearer' audio with lesser noise and hiss in his recordings at a much lower level (better Signal to Noise ratios).

If we are to use the H4n's internal mic preamps to drive the shotgun/lav mics, I dare to say that the noise level in the recording will definitely be higher as opposed to using a line-level input into the H4n (Tested, proven & learnt from our mistakes).

Personally, I have a few workflows to suit most of our client's needs for 5D/7D's audio recording.

Option #1:
Super simple, low-quality requirements setup.
Using a Beachtek DXA-5D, we just record directly into the 5D/7D...
Drawbacks of this is that we cannot accurately monitor input signal, mic preamps of the Beachtek is noisy, if not worse than H4n solutions......
Benefit of this is that we save precious time syncing audio in post...but we'll only recommend this if clients really, really have no budget.


Option #2:
Simple & no fuss, 2 channel recording setup...Similar solution to using H4n, but instead of using H4n with rather noisy mic preamps, we use Fostex FR2LE CF recorder or another high res 1 bit audio recorder.
Both recording units have very clean mic preamps to drive the microphones.


Option #3:
Parallel recording into 5D or 7D.
Together with option #1 & #2, we add a Beachtek DXA-5D for parallel recording into the 5D/7D.
Different from option #1 is that we run a direct line signal into the Beachtek from our recorders with top-end mic preamps. If audio signal is clean enough in the .mov file, we save a whole lot of time from syncing. If not, we have a high resolution audio file as backup.


Option #4:
When more mic inputs are needed, we add a mixer to the chain.
4 channel field mixer, line input into our recorders and parallel output into the 5D/7D.


Option #5:
Most troublesome setup for recording up to 8 individual audio tracks.
Using our multitrack field recorder, we can record 8 independent audio tracks, do a mixdown stereo output into the 5D/7D for sync.



Of course, there are better and more top-end setups from other professional location sound recordists, but given today's budget for production, it's hard for us to justify investing in audio recorders or audio recording solutions that can cost even more than a Sony EX3 camera....

Having said all that, it's also not just about having top end hardware & equipment....one of the key factors other than having good equipment is always the skills and knowledge in mic placement and mic selections to do the audio recording job.....very much like how we change lenses & position the cameras to suit different framing and shot sizes.

If you've reached that kind of level of sound recording requirements, it's best to hire the pros for their services. :thumbsup:
 

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I guess for most people, as long as there is sound, they're happy, but if we're to be anal about our sound quality, we should be more aware of how our audio signal path flows.

Both method of recordings are valid solutions, but I would think that Videoman's solution is a better one.....Firstly, his Sound Devices 302's microphone pre-amps is a lot cleaner than the H4n. By using line level signal to feed into the H2 recorder, he's definitely getting a cleaner audio signal into the H2. As such, he could probably record a much 'clearer' audio with lesser noise and hiss in his recordings at a much lower level (better Signal to Noise ratios).

If we are to use the H4n's internal mic preamps to drive the shotgun/lav mics, I dare to say that the noise level in the recording will definitely be higher as opposed to using a line-level input into the H4n (Tested, proven & learnt from our mistakes).


Personally, I have a few workflows to suit most of our client's needs for 5D/7D's audio recording.

Option #1:
Super simple, low-quality requirements setup.
Using a Beachtek DXA-5D, we just record directly into the 5D/7D...
Drawbacks of this is that we cannot accurately monitor input signal, mic preamps of the Beachtek is noisy, if not worse than H4n solutions......
Benefit of this is that we save precious time syncing audio in post...but we'll only recommend this if clients really, really have no budget.


Option #2:
Simple & no fuss, 2 channel recording setup...Similar solution to using H4n, but instead of using H4n with rather noisy mic preamps, we use Fostex FR2LE CF recorder or another high res 1 bit audio recorder.
Both recording units have very clean mic preamps to drive the microphones.


Option #3:
Parallel recording into 5D or 7D.
Together with option #1 & #2, we add a Beachtek DXA-5D for parallel recording into the 5D/7D.
Different from option #1 is that we run a direct line signal into the Beachtek from our recorders with top-end mic preamps. If audio signal is clean enough in the .mov file, we save a whole lot of time from syncing. If not, we have a high resolution audio file as backup.


Option #4:
When more mic inputs are needed, we add a mixer to the chain.
4 channel field mixer, line input into our recorders and parallel output into the 5D/7D.


Option #5:
Most troublesome setup for recording up to 8 individual audio tracks.
Using our multitrack field recorder, we can record 8 independent audio tracks, do a mixdown stereo output into the 5D/7D for sync.



Of course, there are better and more top-end setups from other professional location sound recordists, but given today's budget for production, it's hard for us to justify investing in audio recorders or audio recording solutions that can cost even more than a Sony EX3 camera....

Having said all that, it's also not just about having top end hardware & equipment....one of the key factors other than having good equipment is always the skills and knowledge in mic placement and mic selections to do the audio recording job.....very much like how we change lenses & position the cameras to suit different framing and shot sizes.

If you've reached that kind of level of sound recording requirements, it's best to hire the pros for their services. :thumbsup:


Hi Dixon,

Nice comment. Should charge for this sharing. maybe can start a workshop or something.
 

Hi Sam,

Thanks for the kind comments. :D

I don't see the need to charge for this bit of info since I always believe that everyone can have the money to buy the best gears & tools available, but if they don't have the skills, knowledge and experience to use it, it's a bit pointless anyways....that's why my business emphasis is always about the services that we can provide, but not equipment that we can supply.

Anyone can go rent the best gears from our local rental suppliers, but if they don't find the right talent for the job, it makes no difference. :D
:thumbsup:
 

Sending a padded down signal from the 302 into the 7D direct seems to work.

From the setup menu, change the XLR Attenuation Level setting to -10db on the left channel only. Note that only the left channel is lit up with a green LED. If the right channel still has a orange LED lit up, keep on pushing the left (Meter brightness) button.

That should send a 1kHz tone that the 7D reads roughly at about -20dB.

Did this for one shoot and the feedback was that most of the audio was usable.

Of course you should still use the tape outs on the 302 to record on an external recorder. At any rate, this setup definitely works towards helping Plural Eyes sync up the audio better.
 

Sending a padded down signal from the 302 into the 7D direct seems to work.

From the setup menu, change the XLR Attenuation Level setting to -10db on the left channel only. Note that only the left channel is lit up with a green LED. If the right channel still has a orange LED lit up, keep on pushing the left (Meter brightness) button.

That should send a 1kHz tone that the 7D reads roughly at about -20dB.

Did this for one shoot and the feedback was that most of the audio was usable.

Of course you should still use the tape outs on the 302 to record on an external recorder. At any rate, this setup definitely works towards helping Plural Eyes sync up the audio better.

The only problem with attenuated/padded 302 output into 7D is that the AGC in the camera is still functioning.....the Beachtek defeats this AGC circuitry by sending a pilot tone @ 21khz to fool the AGC into thinking that there is a consistent input level so that the gain control doesn't kick in and out.

This prevents any possibility of 'gain riding' symptom or 'pumping' noise levels in the 7D's recording....hope canon will add in a AGC disable feature soon. :thumbsup:


Anyways, to be very honest, the Beachtek is only useful for the AGC defeat feature.....mic preamps sucks, and the unit isn't as quiet as it should have been.
But then again, their audio products all along have been developed in mind for the regular consumer grade video cameras....so no complains. :D
 

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Isn't there a private firmware upgrade somewhere for the 5DmkII? Voids your warranty but I remember reading it did the trick.

Maybe that guy might do one for the 7D as well.

Hey Dixon, have you got a 7D or 5DmkII on you? I'm wondering if it's possible to create your own pilot tone and send it through the mixer to defeat the AGC.

I'll give that a go if I get onto another shoot with the 5DmkII.
 

Hi Takuya,

Unless you can find an oscillator or audio signal generator that is super stable and compact enough to output a consistent 21khz sine wave, I think it the best solution now is still the Beachtek....

It also offers you XLR connections over the stereo mini so that we can use our multicore XLR cables without fuss.

BTW, Beachtek told me that they're gonna release new models for DSLR audio...so hopefully new models will be avail soon.
 

Someone's one step ahead of me!

http://www.dvinfo.net/forum/canon-eos-5d-mk-ii-hd/235918-blog-about-how-record-sound-5dmk2-3.html

I think it might work just generating a 21kHz tone and then sending it to the camera. The problem then would be how loud and how long can the cable be. Sounds like a possible plan.

At the end of the day, I think what's more important is to get a decent sound recorded into the 5DmkII so that it is easier to sync up in post. I suspect there are many a horror story where the camera was on a telephoto lens and far far away from the talents, talents are have wireless mics on them and are recorded on a separate system, so no usable audio was recorded with the footage. And thus Plural Eyes became redundant as it did not have a guide track.
 

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