View Full Version : kind of urgent: no audio recorded...
Douglas Joseph June 2nd, 2009, 10:02 PM Hey, guys. I scoured this board looking for an answer with no avail... so yeah. I recently shot an interview. All the clips recorded audio except for one! The 15th clip out of like 30 just has no audio.... the 16th clip, and al the rest do. It's strange. The mic had to have come unplugged on something. Has this ever occurred to anyone, just no audio in a clip for no reason? And is there a way to recover the audio? I'm guessing there isn't. Hopefully I don't have to reschedule for one clip... Thanks in advance, guys. Thanks for letting me dump my problems onto you. Hahaha.
Marcus Marchesseault June 2nd, 2009, 11:52 PM Maybe it came unplugged enough to not record but to keep the onboard mic disengaged? I assume you aren't having problems with a slow memory card causing the record buffer to fill. That would be my stab-in-the-dark guess.
Douglas Joseph June 3rd, 2009, 09:03 AM Hopefully that was the case... If not, I'm going to be paranoid every time I record audio now. I don't think there's a way to recover it. I've never heard of it being done, and I don't see how it'd be possible. Gosh... sucks. Oh well.
Tommi Hares June 3rd, 2009, 10:18 AM I had a similar problem on my Mk II. I traced it to a bad connection of the Mic input jack (bad or "cold" solders?). Take your camera to the service, they'll fix it.
Jason Linn June 3rd, 2009, 10:29 AM Hopefully that was the case... If not, I'm going to be paranoid every time I record audio now. I don't think there's a way to recover it. I've never heard of it being done, and I don't see how it'd be possible. Gosh... sucks. Oh well.
I say do some tests with it at home, moving the mic cord around. Something happened that made the audio engage half way through, so that's a start. Maybe it got bumped or something? Also, if u have batteries in the mic, check those! It's easy to forget about. Otherwise sounds like a short to me, either in the camera body (I hope not!) or in the mic.
That really sucks to have to re-shoot!
Bill Binder June 3rd, 2009, 10:38 AM This right here is one reason why for mission critical things, I would NEVER, EVER trust the 5D2 audio section. No matter what the cause of this, if you could have monitored, it would have been caught. And if it was a partially disengaged plug, just goes to show the exact same thing could still happen even with a preamp in front or anything else in front that you could have been monitoring (not monitoring post deck, then it almost isn't even worth monitoring at all -- not totally true, but this is a prime example of the half-truth no doubt). Now, if/when the Magic Lantern firmware hacks get released and prove to be reliable, having some bouncing meters might have been enough to catch this one, but just saying...
Jason Linn June 3rd, 2009, 12:24 PM This right here is one reason why for mission critical things, I would NEVER, EVER trust the 5D2 audio section. No matter what the cause of this, if you could have monitored, it would have been caught. And if it was a partially disengaged plug, just goes to show the exact same thing could still happen even with a preamp in front or anything else in front that you could have been monitoring (not monitoring post deck, then it almost isn't even worth monitoring at all -- not totally true, but this is a prime example of the half-truth no doubt). Now, if/when the Magic Lantern firmware hacks get released and prove to be reliable, having some bouncing meters might have been enough to catch this one, but just saying...
Bouncing meters would have def. saved him here. I say always record external for this camera. It's just not there yet.
Douglas Joseph June 3rd, 2009, 03:28 PM Bouncing meters would've definitely been helpful... I think I'm gonna start recording audio separately. That's gonna be fun. Time to shell out some more cash on audio equipment.
Jason Linn June 3rd, 2009, 04:04 PM Bouncing meters would've definitely been helpful... I think I'm gonna start recording audio separately. That's gonna be fun. Time to shell out some more cash on audio equipment.
Def. do some research on this one! good luck!
Jon Fairhurst June 3rd, 2009, 04:37 PM Bouncing meters would've definitely been helpful... I think I'm gonna start recording audio separately. That's gonna be fun. Time to shell out some more cash on audio equipment.If/when you buy a recorder, keep in mind that the inexpensive ones (under $1k or so) have so-so preamps. I've got the MicroTrackII and the result with an AT815b plugged straight in was too much hiss. I've now got the juicedLink CX231 stereo preamp, and am getting much better results. It's active, so I can turn up the gain in the juicedLink and turn down the gain on the recorder.
The juicedLink is optimized for placing in front of a camcorder-type recorder with a 1/8" stereo plug and mic levels. When/if we can set the gain in the 5D MkII and monitor the audio, the juicedLink will be a nice companion.
There's a new Beachtek product that you can put upstream from the 5D, but it's passive (no gain, so you still get preamp noise downstream, if your mics aren't sensitive enough.) It has a built-in pilot tone that helps control the 5D gain, but doesn't solve the monitoring problem.
For the same price as the juicedLink, you can get a mono preamp from Sound Devices. It's active, but meant for feeding an XLR input at line level. You'd need to pad it down and use a converter cable for use with the 5D or other 1/8" mic input recorder. It could work as the front end to a Zoom H4n or MicrotrackII, but costs twice as much as the juicedLink per channel.
Anyway, whatever you get, consider a clean active preamp. If your microphone has a hot output, passive is okay, but if you use a low-sensitivity mic, or want to pick up low level or distant sounds, a clean, active preamp is the way to go. Assuming you have a decent mic, the preamp is the next most important piece of audio gear.
Bill Binder June 3rd, 2009, 05:13 PM Bouncing meters would have def. saved him here. I say always record external for this camera. It's just not there yet.
Yeah, but even bouncing meters isn't enough, not for mission critical work anyway. I mean what if you have noise or a buzz or static stomping all over your signal? Yeah, you'll see the meters alright, but that ain't going to do sh!t for you once you get back and hear the thing. Wireless mics immediately come to mind (if running straight into cam), but you get my point.
Evan Donn June 3rd, 2009, 05:23 PM Or the biggest issue I've had audio-wise - iPhone gsm 'chatter' over the audio, which seems to be worse than that from other phones. If you aren't listening to the recorded signal you won't know it's there until it's too late, and no matter how often you tell people to turn off their phones there are just too many of them around (at least here in the sf bay area) to count on not getting interference.
Jason Linn June 3rd, 2009, 09:28 PM Yeah, but even bouncing meters isn't enough, not for mission critical work anyway. I mean what if you have noise or a buzz or static stomping all over your signal? Yeah, you'll see the meters alright, but that ain't going to do sh!t for you once you get back and hear the thing. Wireless mics immediately come to mind (if running straight into cam), but you get my point.
Agreed. Record externally. The camera has proven time and again that it's not great at the sound side of video. The fact that there's no built-in monitoring of audio (other than on playback) is a dead giveaway. :) at least it has a mic input, I'll give it that much, but I can't say it's worth even using the thing. The three holes in front for the internal mic are pathetic. Even the location is a joke.
Jon Fairhurst June 3rd, 2009, 11:18 PM The three holes in front for the internal mic are pathetic. Even the location is a joke.It's good enough to sync to. That's all I need it for... until we can control the gain and monitor the audio, that is!
Bill Binder June 4th, 2009, 02:39 PM It's good enough to sync to. That's all I need it for... until we can control the gain and monitor the audio, that is!
QFT!
For a while I thought I would feed it the same signal as an external recorder, but even that sometimes ended up actually sounding worse than just using the built-in (b/w not being able to monitor it, having no meters, crappy pres to begin with, and AGC, I found it pretty easy to clip or otherwise mangle the feed -- which made post sync harder, LOL. So, why even bother will all the added fuss of cables and going out of the recorder and into the cam, just let the cam do it's thing, and it's plenty good for sync -- ESPECIALLY with a hand clap or clapper board in there.
Also, as someone who is often alone, and who thusly isn't doing much real logging (LOL), I've also found it somewhat easier as of late to stop/restart the audio recorder with every stop/restart of the camera. Even though each clip needs to be synced, it seems to make it a little easier with a 1-to-1 between audio and video files. That said, there are times when I might just roll audio for a whole interview say, and just deal with multiple video files for one long audio file. Kind of depends on what you're doing I guess.
Another totally guerrilla thing I do on occasion, in situations where I'm rolling a long, long audio file, is to basically "slate" the start of a shot by shooting the screen of my R44. I'll give you an example. I do a lot of music-related event stuff. So, I'm often rolling audio of the entire show (most often as a 4-chan mix if you care, a stereo pair off the soundboard and a stereo pair of ambient using AKG480s+ck61/62/63 depending on venue and placement). From there, I am mostly a photog, so I'm spending the majority of time shooting stills. However, I do try to shoot one or two whole songs during the show (on a tripod or monopod). For this, if I shoot the screen of the R44, what I get is both the filename of the audio file and the (approximate) timecode of where I'm starting -- both of which are always displayed on the screen of the R44. So, in post, it makes it easy to open the video file, note the filename, find the audio file, then traverse to the approx time location (say 1:52 minutes into the file). From there, I do a manual sync using the waveforms and my ears. Anyway, just a few more ideas for folks to ponder.
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