ZOOM H4n Material lost on SD Card

[Adam Bankhead]

Just want to give this particular subject a bump. I’ve done this type of audio recovery a few times, and it’s been great, but only in Stereo mode. I’m still unable to find a way to solve the “echo” problem in 4CH mode. I’m about to send either a card or a disk image to a professional file repair service to see if I have any luck there…

The fix here is awesome, but doesn’t work if the recorder was operating in 4CH mode.

Has anyone out there figured this out???????

[Pasha Serdiuk]

Thank you for very comprehensive instructions> I did all as you described here and one of the 2 missing files has been saved! This is a tremendous relief to save my 2 hour interview with some prominent British artists. Will keep on trying to get back the second file that was not in the chunk of sound for some reason. Thanks

[Chris Hunziker]

Again several weeks since the last “revival” of the thread and another desperate attempt to save a 4 channel 0 byte recording. Isn’t there anybody out there, who can help with those echo files? Somebody from Zoom?
Please!
Thanks in advance
Chris

[Chris Kehnle]

Hello,
This seems like a great option. I have not started this process yet.
I was wondering if I can use the copied folder in stead of using the card itself?? (I copied EVERYTHING from the card. I am nervous that if I use the card and screw something up, it will be lost forever…
Any thoughts?

Thanks,
Chris

[Chris Kehnle]

Hi Stu,
Did you ever find a solution?!?!
I have a similar problem. I tried to quickly switch from a/c power to battery, and found out the hard way that the batteries in the Zoom were drained when I removed the A/c plug. power shut down before i stopped the record. Then I continued to record a couple more scenes.
When I got back to review audio, I saw that the 1 file read 0kb. I’m at a loss here… If you found anything in your search that may help I’d really appreciate it.
Thanks,
Chris

[Chris Kehnle]

I have a similar problem. I tried to quickly switch from a/c power to battery, and found out the hard way that the batteries in the Zoom were drained when I removed the A/c plug. power shut down before i stopped the record. Then I continued to record a couple more scenes.
When I got back to review audio, I saw that the 1 file read 0kb. I’m at a loss here…PLEASE HELP!!!

[Chris Hunziker]

H4n 0kB File restore (for Mac users)

Works for 2-channel files only. 4-channel files seems to be recorded interleaved and (up to now) there is no software to extract the 2 Stereo channels.

(This is a compiled version that reflects my experiences put together from several forums on the internet incl. this one. Thanks to all contributors!)

1. Do NOT record anything on the card after the mishap (power interruption during recording before pressing stop).

2. Copy the whole content of that card to your Mac with an advanced option in Disk Utility (tested in OS 10.6.8 and OS 10.10.5):

2a Plug in your SD card into the card reader so it mounts
2b Open Applications>Utilities>Terminal
2c In the Terminal window (copy and) paste the following line:
defaults write com.apple.DiskUtility advanced-image-options 1
then press return
2d Open Applications>Utilities>Disk Utility
2e Select your SD card in the list of drives
2f Click the New Image button
2g In the Image Format tab select “Entire Device” and have encryption set to “None”
2h Save your disk image to a drive big enough to hold it, preferably in a new folder.
Now you have a .dmg file that you can use for several trials. Do not double-click that file, leave as is.

3. Download the Freeware Audacity and install in your Mac https://audacity.sourceforge.net/

4. Open Audacity
4a To open your Card Data use: File>Import>Raw Data
4b Select the .dmg file that you created
4c In the dialog box choose the appropriate figures (depends on how you recorded in H4n) e.g.

– Signed 16-bit PCM (ie 16 bit WAV on the zoom)
– Little-endian [leave as is]
– 2 Channels (Stereo)
– Start offset = 910 [this is the normal size of an H4n header. Also try 0 and 2 if you are at 24-bit, or 0 and 1 for 16-bit]
– Amount to import = 100%*
– Sample rate = 48000

* to try out if it works correctly only import a small part. I put 10%
The .dmg file will not be affected. You can try with different settings several times.

4d Click OK and wait.
4f If you find your lost recording, select that section, then use the command “File > Export” and save it under a different file name, with the same settings as your other original sound files.

Again: This works for 2-channel files only. I was never able to restore my 4-channel file as neither Zoom USA nor Zoom Japan could help me “un-interleave” the raw 4-channel data.

Hope that helps
Chris

[Chris Kehnle]

Thanks for the reply Chris! If I recorded after “the incident” am I just out of luck as far as you know?

[Chris Hunziker]

Doesn’t have to be. I found on my card lots of older things that I thought I had erased. It’s possible that parts of your file are overwritten, but I’ll give it a try.

[Chris Kehnle]

I tried the steps listed above and got the large file in audacity. I found a lot of old deleted stuff, and the new stuff, but not the file i was looking for. I will look again to see if it is out of order or something. The clip I’ve lost was about 10 mins I would say and I recorded for about 40 mins after