The Audio on my H4N doens't sync with my GH1 Video! Is my H4N defective?

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Polarjee

Active member
So I just recorded my first interview and when I synced them in Final Cut, they lose their sync within minutes! Am I doing something wrong or do I just have a bad H4N? I'm recordering in Stereo mode as a wav file 48kHz/16bit and I have the newest 1.40 firmware version. I filmed the video in Motion JPEG on HD (720P 30fps) What is going on?

The audio is too fast for the video and its going off about 2-3 frames per minute
Within 7 minutes, its more then half a second off.

I'm praying It's just a setting I have to change and it's not a defective H4N because it's probably too late for me to return it and I won't have time to send it in for repairs! :(

Any help would be awesome! Thanks!!
 
I think you just retime the audio to like 99.5% or something until it gets right. If there's a noticeable pitch change correct for it.
 
Found this on another forum:
http://www.engadget.com/2009/09/19/how-would-you-change-panasonics-lumix-dmc-gh1/2

"With respect to double system sound, I tried that. I bought a Zoom H4N which works very well. But there are issues. It is yet another piece of equipment to setup, plus you need a system for mounting it (I found a pretty good method). You can't just clip it to your belt because you need to see the meters. Plus, it adds more variables that can go wrong (Ie: depleted batteries; pressing record or stop on one device and missing the other device, etc.). Then there's the editing. Syncing is fairly easy on location with a clap board, hand clap or finger snap, but the video and audio need to be synced in Final Cut Pro. There is an issue with drop frame vs. non-drop frame, so the sync may wander over the course of a few minutes. If you slow down the audio to 99.9 percent in FCP, then it works."


The drop frame issue sounds like the problem.
Other ideas..
Does the Gh1 record only at 48khz? Does the recording to the regular video codec (not MJPEG) do the same? I wonder how plural eyes would handle syncing this.
 
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For the umpteenth time - devices that do not have timecode do not sync. They have different clocks which do not run at the same rate. If audio-video sync could be done accurately without timecode, then costly devices with timecode would have no sales.
 
My ZoomH4N audio syncs perfectly with the GH1 - 29.97 or unwrapped 23.98, or 60p - all keep tight sync. I stopped really caring about how long after 20 minutes of tight sync. Using FCP. GH1 footage converted to ProRes.

My 5D, on the other hand. What a mess.
 
I may try to test more than an hours worth, but drift is drift. And I didn't see audio drift even one frame in 20 minutes. So I call the case closed, for me anyway. Sync will be a no brainer for most things I would do. I wouldn't record 2 hour events with the GH1 anyway.
 
I see, well it's strange that some people seem to be having the same problem with me and not. Well anyways, I tried the 99.9% speed thing that that worked for me for all the shorter clips! :D
I also did a test with the HVX200A on a 20 minute clip and in order to sync up the sound perfectly for that, i set the speed of the audio clip to 99.97% speed and matched up to the last frame. otherwise it was way off sync by the end of it. wierd. Well thanks anyways for everybodys help!!
 
Ozpeter said:
For the umpteenth time - devices that do not have timecode do not sync. They have different clocks which do not run at the same rate. If audio-video sync could be done accurately without timecode, then costly devices with timecode would have no sales.
Click to expand...


I am sorry your comment should refer to "mechanical" devices like DAT or video recorders that have a mechanical fluctuation over a period of time and thst is why timecode exists... The H4N has its internal clock and records digital file independent from mechanical speed fluctuations. The problems is only with the NTSC that has the drop frame issue. It´s just a matter of slight calculation. If you use a clapper board and reduce speed to 99.97% you will have everything in sync.

Thank you
 
The H4N has its internal clock
Click to expand...
But clock chips are not 100% accurate. And vary with stability (some are more affected by temperature variations than others, for instance). Obviously the problems become more noticable with longer recordings - with short clips you can get away with it.
 
Ozpeter said:
For the umpteenth time - devices that do not have timecode do not sync. They have different clocks which do not run at the same rate. If audio-video sync could be done accurately without timecode, then costly devices with timecode would have no sales.
Click to expand...

I have been syncing Mini-Disc recorded audio to 29.97 NTSC video, with dead nuts, frame accurate sync, on clips longer than 20 minutes. for years.
 
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I had an old original dvx100 modded to act as a dat. The preamps and a couple of transistors in the path were changed to give better sound, and it works great!
 
Amen digital brethren! I've found that devices that record digitally, sync up great. Even super cheapy recorders. Timecode isn't mandatory, and in fact, I haven't used it in 10 years.
 
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