i bought a canon 7d thinking about taking it back because of the stupid "auto gain control"...

i did find a beachtek unit, and i was wondering is this signal that is placed in the right channel really apparent or is it truely in the 20khz area?

i have a recording studio/soundlab so i can shelf eq or brickwall anything above 17khz and that will eliminate it right?

also is most movies audio recorded mono with one condenser? or is it 2? cause i was thinking about 1 mic over the foreground for subjects in the main scene and one somewhere else for ambience...

any help and suggestions would be greatly appreciated!!

thanks

corey

You can use The juicedLink CX211 or CX231 with a DN101 to amplify the signal and defeat the AGC. Or you can use a recorder like the Zoom H4n if you want to record separately and sync later, like people have been doing with film forever.

And yes, dialog is generally mono. If people are close to one another and you have a good boom operator, then one mic will do. If you will use lavaliers (clip on mics), then you will want to record multiple channels so you can balance things in post. If people don't step on one another's lines, then you can mix down to one channel and still be able to process each actor's lines separately. If it's a Mamet script, people talk at the same time, so you'll want separate channels.

In any case, dialog in the final product is generally mono. On a surround system, it comes from the center channel.

Separate recorder.

And/or just hire a sound guy.

In post, the boom mic is king. Wireless mics are 2nd, plant mics are 3rd. And the goal of ALL of them is capturing the dialog well.

Other than that, nothing is used. Recording ambience in a 2nd track is honestly not of any help. Just get the dialog clearly and post can handle the rest.

is the signal created by the dn101 very audible or is it truely 20khz? if it is i can just shelf it out with powerful eq settings....right?

which is better juicedlink or beachtek? there is a new beachtek unit for 399 coming at the end of the month that is supposed to have new phantom powered pre-amps with the agc defeater?

any news on canon doing the agc removal with firmware?

I'm not sure which of those is better, but I am sure that it won't make a difference if you're running into the 7D. None of the current DSLRs (that I've seen at least) have anything close to good audio.

If you want to run your main audio to camera, get a different camera.

well the 7d does 48khz, and if i use a good pre-amp and a great mic, it would be almost unnoticeable right?

That still would leave you without any way to monitor the audio, as 7D only outputs sound on playback, not during recording.

Even if the AGC could be defeated (until someone does and posts real results, I'm not buying it) the ADC (analog to digital converter) is likely suspect as well. Since no one's ever used the camera without AGC as the chief thing to screw up audio, it's hard to say but I doubt they put anything quality in there.

On top of that, although people mention 48k, there's a lack of into about what bit-depth the camera uses. It's either 12-bit or 16-bit. 16-bit is okay, but with AGC a 12-bit recorder could easily be what Canon used. No one seems to know though and Canon hasn't posted specs that I've seen.

there was this forum coffee something, and the guy tested the new beachtek dxa-slr with the phantom power and pre-amps, with monitor leveling, and it sounded really clean and good in the camera....

i believe its 16bit as it sounds like it..if it were 12bit and 48khz, it would be really muffled and oversampled sounding....

there was this forum coffee something

here'd be my best guess on that:

COFFEY INTERACTIVE • Index page (http://www.coffeyinteractive.com/phpbb3/index.php)

Didn't know they had a forum but I've shopped there, they are one of the two top production audio resources in LA.

It is my understanding that Canon just released a firmware update that includes manual record level control and a meter in the VF.
Apparently someone at Canon is listening.

Does the firmware update apply for the 7D or just the 5d Mark II which it is a major change for?

Firmware upgrade is for 5DII, not the 7D.

Man, to me, double system is the only option with that camera. Every other work around is just so much lipstick on a pig.

From what I've read about all the HDSLRs, double system is required and the tool of choice seems to be the relatively inexpensive H4n by Zoom.

Record your audio directly to the zoom. Camera captures images and reference audio to sync the images with the Zoom's sound files. Some people use a plug in called Plural Eyes to do this. I've only used the 7d once but was able to sync the sound based on a hand-clap at the beginning of the scenes. Not hard at all and didn't require software.

Double system sound is a good option even if you don't "need" it. I realized last week there are times I need audio from a workshop or some other activity but the action is dull. I dont want to run the camera just for the audio. A standalone recorder would solve that.

Man, to me, double system is the only option with that camera. Every other work around is just so much lipstick on a pig.



according to this guy, the juicedlink has a better preamp and cleaner more natural sound than the "seperate" recording devices that are out now...

including the h4n, and the m-audio...check it out...if the firmware comes out for 7d anytime soon, seems like juicedlink is the only real option...

6. Canon 5D Mark II Audio Exposed - Conclusions on Vimeo

On top of that, although people mention 48k, there's a lack of into about what bit-depth the camera uses. It's either 12-bit or 16-bit. 16-bit is okay, but with AGC a 12-bit recorder could easily be what Canon used. No one seems to know though and Canon hasn't posted specs that I've seen.

Quicktime inspector shows 16-bit:

H.264, 1920 x 1080, Millions
16-bit Integer (Little Endian), Stereo (L R), 48.000 kHz

Yeah,

I'm that guy. :)

Overall, the juilcedLink into the 5D2 is surprisingly good. The H4n is nearly as good. The Microtrack II is not so good - unless you drive it from external preamps, and even then it has audible flaws.

Overall, the JL/5D2/ML combo is VERY clean, and amazingly crisp, but slightly harsh. The H4n is about 6dB noisier and slightly soft or mushy by comparison. Both give professional, but not audiophile, quality.

juicedLink now makes the DN101 for fooling the auto-gain. It also has a headphone output and meters. I haven't had a chance to test it yet.

So, why is the JL/5D2/ML slightly harsh? I believe that I'm hearing some high frequency aliasing. When Canon updates the 5D2 from 44.1 to 48 kHz, this could help. Of course, the other Canon cams already do 48 kHz.

Why is the H4n a bit mushy? I believe that I'm hearing phase distortion. If the highs and lows are slightly delayed from one another, the result is a smeared edge. This isn't something that is fixed by simply cranking the HFs. Similarly, the JL/5D2/ML isn't crisp because the highs are boosted. The frequency range sounds pretty flat to me.

But the differences are slight enough not to worry. Both solutions will sound great for many applications. I've heard our JL/5D2/ML recordings in a theater (48 Hour Film Project), and the noise level was nice and low without any noise reduction being applied. Still, it was slightly harsh in that environment, but our sound quality was among the best of those who participated. I'd want better for a Hollywood release though...

so a dn101 and a juicedlink cx231 combo with a studio recording condenser mic on a boom pole will sound good right?

will it blend with my ex1r? i will be recording from boompole into that camcorder and using the 7d for alternate scenes...

Yeah, it should sound good, due to the clean preamp. I haven't tested it though, and I don't own a 7D, so I can't offer any details.

For those who are happy with the results you're getting, more power to you. For me, I would never trust a setup that relied on fooling the autogain of a camera with funky preamps for anything critical. Can you really be sure that you are always calibrated correctly? To say that you heard sound recorded to the camera in a theater and it sounded fine, well, I'm not sure that really tells us anything. If you record a nice strong signal to practically any device it can sound all right. It's what you don't know you are missing -- that's where the real loss is. But I would say, definitely, that if you concentrate on good recording techniques, with good mic placement, proper levels and gain staging, you can get surprisingly good results with the humblest of tools. So I'm not saying that audio recorded with the Juicedlink/7D combo is necessarily going to be bad. Just for me personally, it all just seems a little too wonky to trust. It would be really great if somebody were to actually conduct a test of the signal to noise ratio, frequency response and distortion of this combo. It would sure take a lot of the subjectivity out of the debate. There certainly do seem to be a lot of people who would like to record direct to that camera. Also, even with the cleaner preamps of the Juicedlink, you can't bypass the preamps in the 7D altogether. All you can do is force them down, and at a certain point you are increasing the distortion and possibly encountering an impedance mismatch. The sweet spot on the gain for most camcorders is usually about one third of the way up from the bottom. I don't know how you can be certain exactly what the internal preamps are doing on the 7D.

recording directly to camera saves time, and is way more practical and convenient with todays technology...

the only reason that the film inustry recorded seperately was to get better sound qualtiy and didnt have good recording directly with the cameras...

todays cameras have the ability with technology to record high quality sound...

Again, I don't have a 7D and I haven't tested the DN101.

[NOTE: I've edited the following for accuracy.]

I do have the 5D2 and have tested it with the juicedLink with Magic Lantern. I set the gain to +17 dB in analog and zero in digital, preserving the maximum dynamic range. With my specific test setup, noise hovered around -96 dB, which would be the theoretical limit of the 16-bit recording. The results were about 6dB better than the H4n.

And I don't know why the juicedLink would be a "funky" preamp. Okay, the name is kind of funky :), but this thing has some of the cleanest gain that you'll find. (I see you were talking about the Canon preamps, which aren't super clean on their own, but exhibit no bad behavior. Note that the Canon AGC is done digitally, not in the preamp.)

From my tests with the Beachtek and 5D2 with stock firmware, the signal jamming approach drives the digital gain down to or near zero. The problem was the analog section. It's set on the 5D2 to a fixed +31 dB. It's possible that even with a clean signal, the noise could be around 14 dB higher than on the 5D2/ML setup. It could be higher, due to bleed from the AGC defeat signal, but it really needs to be tested to know for sure.

It will be interesting to see how Canon programmed the analog gain in the new 5D2 firmware. They have one adjustment. Does it control the analog side, the digital side, or does it mix the two?

My feeling is that with the expected noise, some will be happy with that performance with the advantage of not having to sync. Others will prefer a double system. A third option is to use a field mixer into a top recorder and to feed the line level into a juicedLink and 7D as a clean sync track. This is especially good if you are using a wireless system and the 7D internal mic wouldn't be able to pick up the dialog. It also gives you a backup track, if something goes wrong with the primary recording.

Jon have you had a chance to play/compare with the Tascam DR100?
I exchanged my Zoom for the Tascam because I liked to features better, never tested the audio fidelity though.

will this work with the 7d? it looks like it will....


Used Cavision | RS1580S-SPE Shoulder Pad with Rod | RS1580S-SPE

recording directly to camera saves time, and is way more practical and convenient with todays technology...

the only reason that the film inustry recorded seperately was to get better sound qualtiy and didnt have good recording directly with the cameras...

todays cameras have the ability with technology to record high quality sound...

"Saving time" and "more practical and convenient" are valid criteria only if you do not have to compromise in any way on quality in order to obtain them. For the most part, today's cameras are able to record usable to good sound, that's true. But the objective isn't just getting usable sound, it's getting the very best sound possible under the conditions where you're shooting. A solution that compromises quality in order to achieve convenience is not an option, IMHO.

also what is the best way to edit 7d footage in premiere pro cs4? i have avch and h.264 codecs and presets....the 7d records in .mov files, and its really slow...



heres my computer specs:



core i7 920 3.4ghz 8 mb cache

triple channel memory 3 x 1 gb ddr 3 @ 1.7 ghz

SLI 2x geforce 8800GT's both overclocked

WD hard drive 32mb cache



do i need more ram, my cards are pretty fast...

Jon, when I referred to funky preamps I was talking about the 7D, not the Juicedlink, which by all accounts has very nice preamps for the cost.

Regarding your tests, and I mean this respectfully, but I'm skeptical about your test results. If you are really getting 96 dB SNR with that system, then you are achieving better results than any camcorder, or even any 16 bit recording device that I'm aware of. In fact, I don't think that kind of performance is even possible on a 16 bit recorder. I think you need to review your workflow and software, and maybe test it on another device with published specs to see if you can replicate their results. I do very much respect that you are trying to go about this in a scientific way, so please don't feel that I am being combative. Even 75 dB SNR is quite good, and better than many professional camcorders with actual XLR line inputs.

@Brian: I haven't had a chance to try the DR-100, but would love to. It gets consistently good reviews.

@Marco: You're right. I didn't do these tests with calibrated lab equipment. I did the test relatively. So I shouldn't claim absolute numbers for the units. My mistake.

But I did do the tests consistently from unit to unit. The nice thing about the dB scale is that it's relative. I first measured the sensitivity of each unit with a 500 Hz tone. I wasn't able to simply calibrate everything, specifically, because the Beachtek has no gain and it defeats the Camera AGC, so there's no gain adjustment there either. Similarly, the Microtrack II has no analog gain adjustment. The H4n and the JL/5D2/ML were the only units where I could boost gain in the analog domain.

My assumption is that if I used each of these systems with the same mic and performance, that I'd have to boost or lower the gain in post to achieve the desired mix. So I applied gain to my noise recordings based on the calibration levels that I had measured earlier.

The details of the noise test are here: 5. Canon 5D Mark II Audio Exposed - Noise on Vimeo

And you can download an uncompressed recording here: http://p3pictures.com/audio_5d2/AudioExposed_Part5_Noise.zip

Regardless of the numbers, the juicedLink clearly has the lowest noise - especially as we move up the frequency range. Frankly, the thing is eerily quiet, considering what I had expected plugging into a 1/8" jack on a still camera.

Watching the video again, I had forgotten that I ran the analog gain of the camera at +17 dB. (I've been running +10 dB these days.) So, with the 7D analog gain likely fixed at the maximum of +31 dB, I'd predict that the DN101 will have at least 14 dB more noise than my JL/5D2/ML test produced. It could be more, due to the bleed of the AGC jamming signal.

But again, I haven't tested it.

And thanks for reminding me that my tests were not absolute, but relative. I shouldn't have quoted the numbers as such.

Firmware upgrade is for 5DII, not the 7D.


Contact canon for these features to be added as well, but you gotta love software limitations!!

Here's a completely different way to do it if you are working with Sony Vegas or FCP. There is a plugin called "PluralEyes" from Singular Software which lines up video clips by their audio. You could record the audio on a separate recorder and use PluralEyes to line them up using the lower quality camera audio as a sync guide.

Singular Software (http://www.singularsoftware.com/pluraleyes.html)