Corrupt wav files with Zoom H6 at DVinfo.net

Go Back   DV Info Net > The Tools of DV and HD Production > All Things Audio

All Things Audio
Everything Audio, from acquisition to postproduction.


Reply
 
Thread Tools Search this Thread
Old August 31st, 2015, 04:17 PM   #1
Regular Crew
 
Join Date: Jan 2005
Location: Vancouver, BC
Posts: 196
Corrupt wav files with Zoom H6

I have some audio files from my Zoom H6 that seem corrupt in a bizarre way I can kind of hear the voices for a split second but they are interrupted by sharp, loud bursts of static that are very rhythmical, like a metronome or something. Has anyone encountered this before and know what is causing the problem? Am I getting wild interference? I was recording with both a boom mic and a lav, and both tracks have this intermittent static. Here are the audio files if you want to take a listen and here what I am talking about:

https://drive.google.com/folderview?...FE&usp=sharing

Is there anything I can do to salvage this audio? Does anyone know where along the chain this file went wrong? Thanks in advance.
Mitchell Stookey is offline   Reply With Quote
Old August 31st, 2015, 05:53 PM   #2
Trustee
 
Join Date: Jan 2011
Location: Pennsylvania
Posts: 1,359
Re: Corrupt wav files with Zoom H6

Did you hear that noise on your headphones while you were recording?
Greg Miller is offline   Reply With Quote
Old August 31st, 2015, 06:01 PM   #3
Regular Crew
 
Join Date: Jan 2005
Location: Vancouver, BC
Posts: 196
Re: Corrupt wav files with Zoom H6

No, it sounded good through the headphones.
Mitchell Stookey is offline   Reply With Quote
Old August 31st, 2015, 08:36 PM   #4
Major Player
 
Join Date: Mar 2010
Location: Raleigh, NC, USA
Posts: 677
Re: Corrupt wav files with Zoom H6

Quote:
Originally Posted by Mitchell Stookey View Post
...interrupted by sharp, loud bursts of static that are very rhythmical, like a metronome or something.
Could be RFI from a cell phone. IDK.
Bruce Watson is offline   Reply With Quote
Old August 31st, 2015, 10:45 PM   #5
Inner Circle
 
Join Date: Feb 2009
Location: Brisbane, Australia
Posts: 2,261
Re: Corrupt wav files with Zoom H6

Looks like a file based corruption to me. Attached is an image of the visual of what audio content is in the file. Best to take it up with the manufacturer.

Andrew
Attached Thumbnails
Corrupt wav files with Zoom H6-corrupted-audio-visual.jpg  
Andrew Smith is offline   Reply With Quote
Old August 31st, 2015, 10:53 PM   #6
Regular Crew
 
Join Date: Jan 2005
Location: Vancouver, BC
Posts: 196
Re: Corrupt wav files with Zoom H6

The files recorded later in the day at a different location came out perfectly fine, and all other uses have too. We were in the hallway of a University when filming, so I'm not sure if there was some kind of signal we were picking up, but like I said before it wasn't coming through on the headphones at the time.
Mitchell Stookey is offline   Reply With Quote
Old August 31st, 2015, 10:59 PM   #7
Inner Circle
 
Join Date: Feb 2009
Location: Brisbane, Australia
Posts: 2,261
Re: Corrupt wav files with Zoom H6

Reckon that if it was an interference signal it would look very different as your 'interference' is completely blocking out all other audio for its duration. Hard to know for sure.

Andrew
Andrew Smith is offline   Reply With Quote
Old September 1st, 2015, 01:13 AM   #8
Inner Circle
 
Join Date: May 2005
Location: Burnaby, BC, Canada
Posts: 2,963
Re: Corrupt wav files with Zoom H6

Check your card write speed. Corruption tends to happen on a slow card, and at 48khz/24bit, 2 channels alone use up 2mbps so 6 channels would take up almost 7mbps.

Also, better to use SDHC cards since SDXC support is bleeding edge for Zoom at this moment on the H series, (only the H6 supports it) so there may be card compatibility issues.

Avoid Sandisk Ultra, as those cards are notorious for not delivering the advertised write speed.
__________________
I wait for the day cost-efficient global shutter 60fps capable CMOS sensors emerge for use on major manufacturers' cameras. (Sony, Canon, etc.) Rolling Shutters are a plague.
Jack Zhang is offline   Reply With Quote
Old September 1st, 2015, 03:39 PM   #9
Inner Circle
 
Join Date: Feb 2007
Location: Tucson AZ
Posts: 2,207
Re: Corrupt wav files with Zoom H6

I had something like this happen and a Forum member suggested a fix that actually worked.

In my case the problem was a dropped byte here and there, probably because the card wouldn't keep up with the write data rate.

The fix (drumroll) was to look at the damaged file in a basic text editor and add a byte somewhere at the beginning (ahead of the noise). This corrupted the previously good parts and un-corrupted the bad parts and a bunch of cutting between the two did the trick. Of course I was only recording in Stereo so it was easier.

No idea if this is really your problem or not but it sort of sounds the same as my problem so maybe worth a try.

I'm leaving for an appointment now but I'll be happy to give it a try this evening. In the meantime I think if you search my posts you might find the actual advice I got.
Jim Andrada is offline   Reply With Quote
Old September 1st, 2015, 06:01 PM   #10
Inner Circle
 
Join Date: Feb 2007
Location: Tucson AZ
Posts: 2,207
Re: Corrupt wav files with Zoom H6

Just looked at the image Andrew posted. Wow - this is a mess. It's so totally regular it surprises me.
Jim Andrada is offline   Reply With Quote
Old September 2nd, 2015, 01:37 AM   #11
Inner Circle
 
Join Date: Feb 2007
Location: Tucson AZ
Posts: 2,207
Re: Corrupt wav files with Zoom H6

Here's a link to the original thread.

What you have is much worse than what I was dealing with - I only had 6 or 8 hits in a 2 hr recording. Not even sure it's the same issue.

But for what it's worth. Oh yeah - it seems to have been deleting a random byte instead of adding one (but either might work - or not work) that did the trick

What on earth bit me?????
Jim Andrada is offline   Reply With Quote
Old September 2nd, 2015, 02:43 PM   #12
Trustee
 
Join Date: Oct 2002
Location: Phoenix, AZ
Posts: 1,682
Re: Corrupt wav files with Zoom H6

Were those mics wired or wireless? Was the Zoom on battery power or being powered by the usb port.

I have heard interference like that before but it was coming from dirty power being caused by construction right outside the building. The rate of the pulses was matching the rate of the tool they were using to break up the sidewalk. We ground lifted everything and dropped a Furman in line and it cleaned it up. But I don't see how that could apply to your set up.

Please let us know what you figure out. That is scary considering your cans were clean. If it is a card problem then feeding a camera the line out might have saved you. But I just made a ridiculously long post about how that works.

Kind Regards,

Steve
__________________
www.CorporateShow.com
Been at this so long I'm rounding my years of experience down...not up!
Steven Digges is offline   Reply With Quote
Old September 2nd, 2015, 11:09 PM   #13
Regular Crew
 
Join Date: Jan 2005
Location: Vancouver, BC
Posts: 196
Re: Corrupt wav files with Zoom H6

Thanks everyone for your ideas and suggestions trying to solve this problem. We were using batteries, and 1 track was a Sennheiser MKH-416 shotgun and the other a G3 Lav and both tracks have the same static interruptions.

I opened the wav as text like Jim suggested and it's not simple binary, its a lot of gobbledigook to me, so I wouldn't know where to begin tweaking any of that to make a difference.
Mitchell Stookey is offline   Reply With Quote
Old September 3rd, 2015, 04:10 PM   #14
Trustee
 
Join Date: Jan 2011
Location: Pennsylvania
Posts: 1,359
Re: Corrupt wav files with Zoom H6

I've measured the distance between the first sample in each noise burst. (Not through the entire file, but through several successive bursts near the beginning of the file.

In each case, the distance between the start of the bursts is exactly 65536 samples. That's exactly 2^16. So it appears to be some addressing issue. Whether it was a card failure, failure of the recorder, or what happened, I won't speculate. But this was not noise or interference that infiltrated the recorder and get recorded in any way. It's a data failure for sure.
Greg Miller is offline   Reply With Quote
Old September 3rd, 2015, 08:38 PM   #15
Inner Circle
 
Join Date: Feb 2007
Location: Tucson AZ
Posts: 2,207
Re: Corrupt wav files with Zoom H6

I opened it and did the byte tweak and it unfortunately didn't seem to fix it. Like Greg, I was bothered by the regularity of the noise. Unlike Greg I didn't think to count samples

I think the actual block write size for an SD card is supposed to be 512k but a lot only write in 128k blocks.

So I'm wondering if the"noise"/"damage" might be occurring at a rate that would correspond to the writing of actual data blocks - ie X blocks get written correctly, Y blocks get hosed, with regularity which could point to an inability of the card to keep up with the data rate.

Oh well, just speculation
Jim Andrada is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > The Tools of DV and HD Production > All Things Audio

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 03:57 PM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network