Dual Audio Recording with AG-DVX100

[Kevin Merker]

Hello,
This is my 1st post on this forum. OK! I need a little help on finding the best external audio recording device to work with the AG-DVX100. After reading Ken Stones writings on dual audio recording systems and problems of using one. http://www.kenstone.net/fcp_homepage/location_sound.html#link%20one. I was really deflated. Has anyone used an external recording system that can be easily resynced in post? Can someone throw me a bone on a audio recorder system that works with the AG-DVX100 that stays in sync?

All an any input on this problem being solved will save me lots of time and money.


Thanks,
Kevin

[Conrad Williams]

Digital is digital. It should stay in sync, except for very long record times. Even then, just cut out a frame or two and you're back in sync.

In order to sync up the material, use a slate and line up the sound to video. It's more work in post, but it's a monkey job that anyone with a little NLE experience can do. Pay your teenage nephew 5 bucks an hour to do it. He'll love you for getting him out of his McJob and onto a computer.

If you're not planning on theatrcal exhibition, the sound on the DVX would probably be enough for you anyway. Get a good mixer and go line-in.

[Jeff Donald]

The camera has an audio delay of several frames in some modes and I know several users that rutuinely have to sync adjust all the audio. It should not be a big problem. No way to save time, the delay is a big problem for some producers for others it is a quick adjustment and they are good to go. What NLE are you using?

[Mark Briody]

I was recently asked to record a meeting. The budget was shoestring and I didn't want to use the on-camera mic.

I put a consumer level Minidisc player on the meeting table and recorded using a $30 AKG lavalier mic laying down. Granted, this is far from the best way to record audio, but for this project it ended up working well.

I also recorded on camera audio to use as a reference.

In post, I panned the on-camera audio hard right and the minidisc audio hard left. I put on a set of headphones and listened for left-right delay (which signifies a sync issue). This made it relatively easy to sync the audio from the minidisc with the on-camera audio (a 5 frame difference for 30 minutes of video).

Once the on-camera audio and minidisc audio were in sync, I turned off the on-camera track used a section of video where I dropped a pencil on the table. Using that small snippet of video allowed me to compensate for audio sync issues with this camera (another 1 frame in this example, typically 2 in everything I have read).

I also cleaned up the sound in a dedicated audio editor. I removed noise, eq'd and compressed the audio track.

The client ended up being VERY pleased, since they were used to on-camera audio from a VHS camcorder.

Mark

[Clayton Farr]

<<<-- Has anyone used an external recording system that can be easily resynced in post? Can someone throw me a bone on a audio recorder system that works with the AG-DVX100 that stays in sync? -->>>

Hi Kevin,

The relationship between an external recorder and the DVX100 will be the same as the relationship between such a recorder and any camera. You will want to have a definitive way to reference sync when connecting the two back again in post. (This is certainly the case if the audio is actually being recorded separately from DV tape, but with the DVX100 it is also helpful to have a means to confirm sync even if recording audio back to camera - more info below.) When producing narrative work, a clapboard would probably be the easiest reliable means to do this.

FWIW, the DVX100 has been reported as being toward the front of the pack in terms of audio recording quality among DV cameras (this is referring to the recording circuitry not the onboard mic itself.) I believe there was an in-depth article about this in DV magazine recently (www.dv.com.)

The primary benefits of using a dual system, as you may be aware, are removing the microphone from the camera (onto a boom pole or the like) and having a separate individual monitor the audio side of things, preferably through a mixer. With these things in place you can then choose whether or not to use the camera as the audio recorder (with the mic/mixer being tethered back to it) or record to a separate medium (ie - DAT) and use the DVX100 as a back up recorder or scratch track via onboard mic when possible.

(Another FWIW, many people also have used either MiniDisc recorders or something like the Nomad Jukebox hard drive recorders instead of DAT. I can't speak personally to either of these solutions, but there is good info to be found about them online. [www.lafcpug.org may mention these amidst some of their audio articles.] I don't believe either one will keep precise sync with the image [irregardless of camera] over especially long takes [over 10 minutes?] - but these would usually not be a problem in narrative but might be present in documentary work.)

As mentioned the DVX100 does have an internal sync issue, especially pronounced when recording in the 24p modes. (Unfortunately, this discovery was a hard won initially...) Adam Wilt has done an excellent job of detailing what is going on in his page on the DVX100 (www.adamwilt.com/24p.) But the short of it is that the audio is laid to tape approximately 2 frames ahead of the picture. This appears to be consistent and isn't difficult to fix in post if you know to look for it. One can either default to pushing the audio forward 2 frames (or have it done while processing pulldown through a utility like DVFilmmaker) but I've found that I still like to use a clapboard even when using the camera as the primary audio recorder so I can manually match/check sync in the NLE for confidence.

So all that said, the choice of an external audio recorder probably comes down more to the cost/quality that your project(s) dictate rather than anything to do with using it with the DVX100. And as mentioned before, if it can work to have the audio personnel tethered to the camera itself, the DVX100 does a respectable job as an audio recorder even though you will still need to adjust/check sync in post.

Hope this helps - good luck with your project,
Clayton