Zoom H6 line out phase inversion problem

[Geoffrey Cox]

Originally Posted by Don Palomaki

On audio sync to video. Light travels much faster than sound, about 186,000 miles per second vs. ~1000 ft/sec. So audio lagging video slightly corresponds to standing back a bit further from the source. Our brains process it. However, audio leading video is unnatural
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'Unnatural'? But video is unnatural in the first place, it is all an artifice. I work on many occasions with audio leading video. It is called art, and being 'unnatural' is half of what art is about. We may receive the image quicker than sound to our senses but that is not the same as our brain registering it as such. As has been pointed out many times, sound is more emotive than image as it is less definite and has porous boundaries (and it is speculated that in terms of flight and flight survival of early man, it was more important as you could hear danger way before seeing it), so in fact it is the sound that people often notice first and what stays with them long after the images have faded.

[Greg Miller]

IMHO video displayed on a screen is no more natural or unnatural than audio reproduced by a loudspeaker. However, I agree with Don (and it's an indisputable fact): in the natural world (no recording or playback involved) it is inevitable that sound will reach an observer somewhat later than the light from the corresponding visual event; the reverse *never* happens.

I have observed, in any lip-sync combination, that sound-early playback is much more noticeable and objectionable than sound-late playback. (e.g. people sitting in the back row of a 100-foot-long theatre don't complain that the sound is out of sync)

The comments about polarity-flipped stereo, while true, seemingly don't apply to the OP's workflow as he describes it.

Glancing at the Zoom manual, there seem to be some menu-driven mixers. I wonder whether there is some configuration setting in one of those mixers which might be causing the observed problem.

[Patrick Tracy]

Originally Posted by Paul R Johnson

Thinking about this, I'm not sure it makes any actually difference practically as I don't think I've ever zoomed in close enough to have ever noticed. After all - the camera audio won't ever cancel completely as the mics are in different places? Plus - there's no point being more accurate than the frame rate - so minute shifts which are possible in an audio editor aren't usually possible in the video editor, locked to frames,

I edit audio and video in Vegas Pro. In that software you can unlock audio from video and move it down to the sample level, which I do routinely.

In a project I'm working on right now, I recorded a band on four cameras and a Zoom H5. The Zoom is getting a feed from the PA plus the onboard mics are capturing sound at the lip of stage, the combination of those giving a fair to very good representation of the live sound. I most definitely slide the direct feed to time align it with the onboard mic track. I usually do the audio in a separate project and drop rendered songs into the video editing project where I again slide it around to make it look correct. I don't just align it to the camera audio because that's often a frame or two off, which I can see. The audio definitely needs to be placed with sub-frame accuracy to look right.

[Charlie Ross]

Patrick, you are describing exactly my live music workflow. Every bit of it.

None of it helps the OP in his present predicament but it's good to read that at least one other person thinks somewhat like I do. Wait until I can tell my friends!!! LOL.

I can't find a service manual for the Zoom to appraise what might be going on in the signal path and I would just "get around" the inversion in software anyway since I am already tinkering on the timeline in detail anyway.
Cheers.

[Patrick Tracy]

Originally Posted by Charlie Ross

Patrick, you are describing exactly my live music workflow. Every bit of it.

None of it helps the OP in his present predicament but it's good to read that at least one other person thinks somewhat like I do. Wait until I can tell my friends!!! LOL.

I can't find a service manual for the Zoom to appraise what might be going on in the signal path and I would just "get around" the inversion in software anyway since I am already tinkering on the timeline in detail anyway.
Cheers.

That's encouraging. I was really responding to the "audio can only be moved by full frames" idea.

I think it's probably as simple as economics. My guess is that the circuit that was good enough to get it done left the signal inverted at the line output. Inverting back to "normal" would have needed one more op amp stage, which would have added to the cost and almost never been noticed. I don't think I've ever used the line out on my Zoom.

[Geoffrey Cox]

Originally Posted by Patrick Tracy

I edit audio and video in Vegas Pro. In that software you can unlock audio from video and move it down to the sample level, which I do routinely.

In a project I'm working on right now, I recorded a band on four cameras and a Zoom H5. The Zoom is getting a feed from the PA plus the onboard mics are capturing sound at the lip of stage, the combination of those giving a fair to very good representation of the live sound. I most definitely slide the direct feed to time align it with the onboard mic track. I usually do the audio in a separate project and drop rendered songs into the video editing project where I again slide it around to make it look correct. I don't just align it to the camera audio because that's often a frame or two off, which I can see. The audio definitely needs to be placed with sub-frame accuracy to look right.

Indeed - sub-frame accuracy is needed. It is one of the frustrations to me that video NLE's do not tend to allow you shift audio at subframe level (once the frame rate has been fixed). In my sort of work it is actually timbre that is a major factor here. Aligning audio tracks right down to sample level accuracy may not be audible in the sense one can tell the time position difference between a few samples but you can hear the difference as the two sounds interact with each other differently. After all, two instances of the same sound misaligned by a few samples can be easily detectable by the ear via the timbre shift.

[Rick Reineke]

Every version of Vegas Pro allows moving audio (and video) down to the sample level, unless it is locked to the frame level. VP also has a substantial DAW built in.. in fact, Vegas was originally an (audio only) DAW before video editing was added. On the down side, it lacks MIDI instruments, does not support VST-3 audio plug-ins or side-chaining..

[Patrick Tracy]

Originally Posted by Geoffrey Cox

Indeed - sub-frame accuracy is needed. It is one of the frustrations to me that video NLE's do not tend to allow you shift audio at subframe level (once the frame rate has been fixed). In my sort of work it is actually timbre that is a major factor here. Aligning audio tracks right down to sample level accuracy may not be audible in the sense one can tell the time position difference between a few samples but you can hear the difference as the two sounds interact with each other differently. After all, two instances of the same sound misaligned by a few samples can be easily detectable by the ear via the timbre shift.

Yep, I use a coincident pair for drum overheads so I have a point to which I can time align all the close mics. It's a similar process to aligning a room mic with a direct PA feed for a live concert recording. The difference is subtle but worth the effort. Control over polarity is important in these contexts, which is why it's nice that Vegas Pro has a button on the channel controls and inverts the waveform display accordingly. And you can do all this right inside a video editing project. These features might be handy for the OP.

Vegas Pro has a "Quantize to frames" check box. I always have it on for video editing and off for audio mixing.

[Geoffrey Cox]

Originally Posted by Patrick Tracy

I edit audio and video in Vegas Pro. In that software you can unlock audio from video and move it down to the sample level, which I do routinely.

In a project I'm working on right now, I recorded a band on four cameras and a Zoom H5. The Zoom is getting a feed from the PA plus the onboard mics are capturing sound at the lip of stage, the combination of those giving a fair to very good representation of the live sound. I most definitely slide the direct feed to time align it with the onboard mic track. I usually do the audio in a separate project and drop rendered songs into the video editing project where I again slide it around to make it look correct. I don't just align it to the camera audio because that's often a frame or two off, which I can see. The audio definitely needs to be placed with sub-frame accuracy to look right.

Originally Posted by Patrick Tracy

Yep, I use a coincident pair for drum overheads so I have a point to which I can time align all the close mics. It's a similar process to aligning a room mic with a direct PA feed for a live concert recording. The difference is subtle but worth the effort. Control over polarity is important in these contexts, which is why it's nice that Vegas Pro has a button on the channel controls and inverts the waveform display accordingly. And you can do all this right inside a video editing project. These features might be handy for the OP.

Vegas Pro has a "Quantize to frames" check box. I always have it on for video editing and off for audio mixing.

I have heard of Vegas of course but never explored it. Went from FCP (original) to Premiere. I've used various audio sequencers over the years but for all its faults, the depth and breadth of Logic is still very good for the price of the thing.

It does sound though as if I should check out Vegas as my work is basically sound-led and I am a musician at heart.

[Patrick Tracy]

Originally Posted by Geoffrey Cox

I have heard of Vegas of course but never explored it. Went from FCP (original) to Premiere. I've used various audio sequencers over the years but for all its faults, the depth and breadth of Logic is still very good for the price of the thing.

It does sound though as if I should check out Vegas as my work is basically sound-led and I am a musician at heart.

I'm probably biased because I've been using this line of software for the better part of two decades, but it definitely does certain things really well. It is worth noting some of the limitations mentioned above. Also, there seems to be a trend of people getting frustrated with it and moving to other software, like Resolve, but I haven't had any of the trouble others have had.

For me the real advantage is that it's very effective with audio and video. I don't have to switch software to work on audio for a video project, though I do often have a separate project for the audio. You can actually nest one Vegas Pro project as a track in another Vegas Pro project.

[Don Palomaki]

Originally Posted by Geoffrey Cox

'Unnatural'? But video is unnatural in the first place, it is all an artifice...

Care to dolly-zoom anyone?

Unnatural, meaning not as it is found in nature. Recorded audio is colored by the transducers used (mic and speakers) A/D - D/A converters used, not to mention recording and listening environment acoustics vis-a-vis the transducers, audio effects processors, and so on. A lot of artistic effects are "unnatural" driven by an intent to provide sensory experiences different from what mother nature provides.

With a single audio source file sub-frame audio shifts are of less significance than when dealing with a mix of multiple sources.

What counts ultimately is what the intended viewer/listener (e.g., paying customer) sees and hears as compared to their expectation.

[Geoffrey Cox]

Originally Posted by Don Palomaki

Care to dolly-zoom anyone?

Unnatural, meaning not as it is found in nature. Recorded audio is colored by the transducers used (mic and speakers) A/D - D/A converters used, not to mention recording and listening environment acoustics vis-a-vis the transducers, audio effects processors, and so on. A lot of artistic effects are "unnatural" driven by an intent to provide sensory experiences different from what mother nature provides.

With a single audio source file sub-frame audio shifts are of less significance than when dealing with a mix of multiple sources.

What counts ultimately is what the intended viewer/listener (e.g., paying customer) sees and hears as compared to their expectation.

Are you trying to claim video (and film) is not also 'coloured' by the technical processes needed to make it happen? If anything video is less transparent than audio - colours are almost never really true to what you are looking at for example whereas a good audio recording can sound almost exactly like what you were just hearing. Also, the post processing of video can be just as 'unnatural' as audio. Virtually every mainstream film I watch looks unnatural to my eye and nothing like 'reality'. Bazin's idea the photograph is a window on the world is false, and increasingly so but we find ourselves in a world where, for example, CGI is consider something that looks good, whereas it is in fact, horribly artificial but we suspend our disbelief - that is how cinema works - we know and see it is all unnatural, but get over it.

What counts ultimately is not fulfilling the audiences expectations but doing the exact opposite.

[Greg Miller]

My lunch was 'coloured' by the technical processes needed to create it. Certainly the french fries didn't taste like raw potato, and god only knows what that Big Mac was before processing.

[Don Palomaki]

Are you trying to claim video (and film) is not also 'coloured' by the technical processes needed to make it happen?

good audio recording can sound almost exactly like what you were just hearing...

What counts ultimately is not fulfilling the audiences expectations but doing the exact opposite..

No. I'm saying audio recordings are also colored. And "almost" can cover a lot of territory

And no recording, audio or video, is an exact representation of the live event. as experienced by the viewer/listener in his/her seat.

This all brings to mind the ads for AR speakers (Acoustics Research) from the 1960s. Behind the stage curtain AR3a vs a live performer. Point source vs point source in a large venue and the best of gear. But a far cry from a pair of speakers vs a 90 piece orchestra.

And a lot of current music is highly engineered - about the only purely acoustic instruments are the drum set and voice and even they are processed, reverbed, and compressed to satisfy the artistic intents of whose making the final calls on the released work

Is it bad? (a mater of taste), is it wrong? (its art so wrong is a matter of opinion)

Except for few wackos and those in chains an unhappy audience is unlikely come back for more.

[Andrew Smith]

Further, the quality of one's (remaining) hearing will also colour the perception of the sound.

Andrew