Freesound Forums

If a current Zoom H4n owner would do an informative test for me, I'd appreciate it. I am seriously considering buying an H4n, but only if it does not have a certain problem that has plagued my past work.

Background: I have a Zoom H4, and my intent was to use it as a second audio source when videotaping interviews, in case there were problems with the audio being fed into the cameras via lapel mics. My expectation was that I could import the audio file directly from the H4 into Final Cut, use a clap at the beginning to synchronize the audio, and be "good to go." That expectation was not met -- the audio would drift. After some online research I found out that the Zoom H4 has a timing issue (I don't understand it well enough to explain it better). Apparently this is an issue with all H4 units, not just mine. The "solution" was to connect the H4 to the Mac with an audio cable, enable recording in Soundtrack Pro, and then play the file from the H4. Obviously this is not a good approach.

I'd like to find out if the H4n suffers the same problem.

The Experiment: Set up a digital camcorder (I was using a MiniDV camcorder, but I expect any digital camcorder would work) and an H4n to record at least 10 to 15 minutes of something (casual conversation, a TV playing, whatever). Then transfer the digital content directly to a computer and either load it into an NLE yourself to see if the audio stays synchronized, or send me the files (I could arrange an FTP server or something, or pay for a disc and shipping within the US).

If you're willing to do this, please let me know!

Since I'm on planning to use my h4n as audio source, I'll try it out and send you the video...

Is the audio not recording at exactly 1second per second? Would it affect to sound quality to do a small tempo-change to stretch the sound enough to sync a reference point at both the beginning and end of the audio? If the shift is small (a second off per 10 minutes) then maybe the change would be unnoticeable. But yeah, it's probably best to get a recorder without the issue in the first place.

sepal
Since I'm on planning to use my h4n as audio source, I'll try it out and send you the video...

(TLDR: The H4n seems closer but is still off; opinions vary on whether that is acceptable/expected.)

Thanks for the input, though!

I know it's one more thing to buy, but have you looked into Plural Eyes? I suspect you could probably create shorter clips in Final Cut to make syncing a bit easier.

Corsica_S
I know it's one more thing to buy, but have you looked into Plural Eyes?

I'd like to find out if the H4n suffers the same problem.

All digital recorders experience clock "drift" to a greater or lesser degree, although generally the higher quality/priced the gear, the less drift is a problem. Clock drift literally means that the internal clock, which ensures the audio is being sampled at a particular sample rate, is inaccurate. Normally clock drift is only noticeable over long durations, i.e. 15 minutes to an hour.

The only "perfect" solution is to use a camera and audio recorder which are capable of being clocked from an external timecode source, i.e. a Denecke box. Needless to say, this kind of gear is expensive.

I've used both the H4 and the H4n in a similar situation to what you described and, although I don't have any data to back this up, I think the H4n was less susceptible to noticeable clock drift than the H4.

I know it's one more thing to buy, but have you looked into Plural Eyes?

Pluraleyes is a convenient tool but remember that it works by comparing the audio recorded by the camera's internal mic to whatever you record with your external recorder. This can result in slight sync offsets when the camera is shooting on a long lens from several feet away and the "good" audio is recorded on a boom above the speaker's head or a lav. Just something to watch out for.

One thing you should consider is that most DSLR cameras are the cause for drifting audio. But since I never used a Zoom h4 or H4n I can't judge if they get out of sync or not.

thaighaudio
The only "perfect" solution is to use a camera and audio recorder which are capable of being clocked from an external timecode source, i.e. a Denecke box. Needless to say, this kind of gear is expensive.

thaighaudio
Pluraleyes is a convenient tool but remember that it works by comparing the audio recorded by the camera's internal mic to whatever you record with your external recorder. This can result in slight sync offsets when the camera is shooting on a long lens from several feet away and the "good" audio is recorded on a boom above the speaker's head or a lav. Just something to watch out for.