Timecode sync

Hi everyone, I m setting up a project in which ill do quite a bit of location recording with a zoom f8n pro and 4-5 cameras. its music related so there is a possibility at some point ill need to record way more than 8 tracks that the zoom has. for this purpose im thinking if i could use a laptop and separately record more channels but using the timecode shared with the cameras and the portable recorder. i saw in another thread that something like the Motu express XT (which is a midi interface) could translate the LTC coming from the zoom into nuendo…is this doable? or is there and alternative and easier way to do it?

I’m afraid that won’t work.
You will need to sync-lock to the Location Sound Timecode.
Which means you need a synchronizer to slave your computer/nuendo to that timecode.
For example the Steinberg Syncstation.
This something your Zoom f8 does out-of-the-box.

Syncing your tracks according a slate or any other sync point will not work.
Since your systems are not looking at the same Clock, you will experience drift.

Fredo

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If I remember corectly, in order to get full synch, you need both timecode and “blackburst” word clock signal from one of the cameras. Correct? It’s been ages since I worked on video projects.

Yup.

Fredo

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Dont know what sort of music related work you are doing, but i did a lot of location recordings of a band for live music videos pourposes. Laptop with 16 in 16 out interface and 4 cameras and 2 go pro cameras.
There was no tc sync, only a slate with a pop or handclap (cameras need to face a slate during a pop for sync, and mics also record a pop).
Did not have any sync issues.
Audio and video were synced in davinci resolve with audio pop sync, and then editor send me aaf for diferent songs.
We did 10 songs, each 3-5 min long.

Yeah, but the OP want’s to record on his Zoom device and on a laptop.

Fredo

Did you use any audio from the cameras for your final mix? Or try to synch the all the audio?

What I am mentioning is SAMPLE ACCURATE synch (yes, that’s the correct spelling). Which requires word clock, which tells the devices about the audio sample rate, locked to a video signal.

But if we’re talking about drift between different devices’ internal clocks how much can it really be over say 5 minutes (more than a song)? And does the sync really need to be sample-accurate in terms of the actual audio captured? I mean, if it’s multi tracking musical instruments or sources then any timing difference would likely be dwarfed by real-world physical differences between mics etc.

What am I missing?

i work i broadcast so of course i know what SAMPLE ACURATE means.
i also know that when work needs to be done, it needs to be done in any way possible.
maybe some one is on a budget and does not have money to buy stuff.
so , i was just offering my expirience working on simmilar project.
audio from cameras were not used in final mix (band was miced as if they were on stage). audio from cameras was just used to sync multitrack audio from my laptop and video from cameras.
as i said sync was done in davinci resolve with no problem. i know it is not sample accurate but it did the job.

it would be more clear if autor of this post gave us a bit more understanding of what he/she is recording and how.
if he/she is recording a band on 2 diferent devices it could be a problem of faze shift and drift between mics.
but it can be done. drums/perc on zoom device (because drums are faze sensitive), close mics (guitar, bas, vox) on laptop.
how much is drift over 5 min song? probably veeeeeery low. its not a big deal to test it anyway

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Hi everyone! sorry for disappearing i had so much work to do!..so anyway a bit more info on the situation…ill be doing a tv project where well be going to various locations to record musicians of all kinds…some are solo others are bands etc…i actually have done the same thing once in the past with only the zoom h6 and with no timecode and it was a real pain as there is dialogue etc that is edited. normally the zoom f8n that has 8 channels should be ok for most of those gigs( most of them will be at location without power outlets very close) but as i said i have no idea(noone has at this point) what kind of bands well be doing(it seems well do over 100 acts for the coming season). so im trying to figure out what the best way is to add channels to the existing setup in case i need more…i was thinking that maybe with the laptop ill have with me anyway and another interface i could add a few channels or more as im hoping that in case they need many mic inputs i could sync them…so is there anyway Nuendo would be the timecode master so i could feed that timecode to the recorder and the cameras? i think well have 4 cameras and the recorder. sorry for being vague we are actually just started preproduction for this.

One thing you could consider - Presumably your are using some sort of lock-it or Tentacle device to sync the Timecode between the cameras and the Zoom. That timecode signal is actually audio encoded at line level. With the right cable you could take the LTC signal and feed it into an additional mono channel on your laptop that is recorded the same way as the other laptop audio channels. Those won’t be recorded in Nuendo with the right timecode, but you can take all the individual recorded audio files and then add the timecode offline afterwards. Tentacle has a utility (and some NLEs can do it too, benefit of Tentacle is that it doesn’t re-encode but just rewrap with new meta data). That way you can attach the proper timecode to the laptop recorded tracks and then re-import them where they can be synced with all your recorder audio tracks accurately. Using a lock it or Tentacle on each camera, the ‘zoom and your laptop will avoid any drift.

Jan

Depends on the accuracy and stability of each clock.

It is important to have in mind that he is recording a band.
So any latency or drift will result in phase issues when mixing the music.
LTC alone does NOT guarantee accurate lock.
A master Wordclock/Blackburst + Timecode does guarantee accurate lock.

Here’s an interesting read about drift:

And the complete SMPTE guide:
https://whitefiles.org/tec/pgs/h16f.htm

Fredo

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@Fredo … That’s knowledge that is slowly but surely lost, isn’t it …

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No, we are just old farts, making everything “difficult” to get attention.
:slight_smile:

Fredo

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Whell, sound like you have a big work ahead yourself. When you get the inpul list (rider list) from bands, you wil have a better picture. Just a reminder, bands usualy need some monitoring for their instruments/vocals. You may encounter some issues there outputing monitoring via zoom (latency).
I would recomend you record everything on laptop with a good interface (example 16 in 8 out) and use nuendo control room to send monitor mixes via soundcard outputs.and set buffer lowest you can so monitoring will be at low latency.
Or rent/buy a small portable digital mixer that has sd card multitrack recording. That way monitorig for band is easy because aux outputs form mixer have no delay.and make shure you always have power outlet close (that 100watt marshal guitar amp dont run on air :slight_smile: )
Nuendo as a tc master? I thin it can be done, did not try that.
But in all honesty, if you are recording a song, a good old slate and a hand clap will do the job perfectly. Just put some one on stage to yell "song 1, take1, and clap that slate/ hand.

I think the takeaway from that article probably should be that for the vast majority it’s really not an issue. Since the Tascam and Fostex have the exact same values and the Tascam values are incorrect I’m guessing the Fostex ones are as well. That leaves the worst case scenario being that one drifts one frame every 37 minutes, which is so bad I have to doubt that it’s true in reality.

—> Also: It should be noted that we don’t know if the entry in the spec sheet is for TC clock generation or word clock sync from external inputs. As far as I understand it a lot of devices have a clock that’s very stable internally but loses precision when clocked from an external source. In other words you gain sync when using a WC BNC input to lock onto, but lose precision. So if the number refers to re-clocking to an external input it won’t actually apply as an argument for why we’d want to clock to external sync to avoid drift specifically.

The other interfaces are probably more the norm and the worst one of them drift one frame over 6 hours. The next worst ones are at 9 hrs, and the rest >46 hrs.

So given that the article is almost a decade old and deals with mostly “no-name” brands (for interfaces) I think realistically it’ll likely be a non-issue. If this is live music and there’s a bunch of mics on a stage then I’d think a timing difference during even a whole set would equal far less than moving a mic somewhat on stage.

As for syncing several devices I’d say just get a large remote / laptop setup and make sure all of those devices are in sync and then just do a “clap” between that and cameras. If it’s possible to record all required musical audio that needs to be in sync on the laptop then if the cameras aren’t 100% in sync I doubt that’ll be a problem. Cut video with camera audio as a guide, mix with laptop multitrack. Don’t see why that should be a big problem.

agree. i would do it that way, and did it that way several times.

Not exactly, that is the drift from ONE machine.
Two (non-WC-synced) machines can double that amount.
Also note that an unstable clock doesnt drift linear, it flutters.
1 frame is app. 40 miliseconds.
That is app. 1 milisecond per minute. (On one device)

When I hear the stories of music mixers who time-align mic that only are a feet apart, this should be a nightmare.

Re-clocking is a problem when you daisy-chain WC.
Because you simply can’t know if the incoming clock is getting re-clocked by the device and/or if the clock is properly “spiltted”. And if the WC is properly terminated in that device.
Hence why House World Clock generators and proper WC distributors exist.

The only proper answer is that the OP needs to record all of the Music tracks on ONE device.
If not possible, then he’ll need a WC Master Clock & SMPTE to lock his devices to.
All of the rest of the sources (Narration/public/…) are not sync-sensitive.
Music is.

Fredo

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You mean if they drift in the opposite direction? Sure. They could also randomly be exactly in sync.

Yeah, but you took the one worst case and ignored the rest, right? If it’s 1ms/minute for the device that drifts a frame per 37 minutes then for all the devices that only drifted by a frame over >46hrs that’s 0.01ms.

As for time aligning mics that are a foot apart that’s only done because they’re that close, and if it is done when they’re that close then a) they’ll do that anyway so it simply doesn’t matter if drift is 0.01ms, and b) sources that are physically adjacent on stage often tend to be adjacent in track layout as well, meaning it’s not unlikely they’d end up on the same device meaning it’s again a non-issue (because they’d all have the same drift).

I don’t disagree. The context was that I said “re-clock” meant the internal re-clocking to an external clock reference. My point wasn’t the jitter of the clock using external WC, my point was that the number in the spec sheet seemed to have possibly referred to that rather than drift.