Syncing external audio with ANY camera and recorder – Tentacle takes the pain out of the butt.

If you are an avid reader of my blog, you probably already heard about the TENTACLE SYNC system.

If not, watch this first.

So, now that you are up to speed, let’s talk about syncing external audio and why it is a pain in the butt.

First of all, why do you want external audio in the first place? Would it be not much faster and more convenient, to record the audio direct into the camera, an skip the whole syncing thing altogether?

Actually yes, it would, but there are some obstacles.

First of all, most on board pre-amps suck. You could work around this, by using a good field mixer, but you still have only two channels. On a typical film set, I have at least 4 channels of audio, sometimes even more – so you run out of channels on your camera pretty fast. What you need is a professional recorder, which brings us to syncing.

You can do that by hand, but it’s not exactly fun, when you have 20 hours of material, so some sort of automatic (or at least semi automatic) syncing is in order.

Most of the “big boys” cameras have a sync plug, to jam-sync the camera with the recorder – but what are you doing when your camera doesn’t have that feature? That’s when the Tentacles come into play. They are little timecode generators, about the size of a matchbox, self-contained with battery and all. You have a master Tentacle, from that all you camera Tentacles get jam-synced. You put those on top of your cameras, plug them into the mic/line input of your camera, and that’s it. It really is that simple and it works like a charm.

They have only one button, and the setup is stupidly easy. What you are doing is, you record the timecode signal on one of your audio tracks. The second track receives a signal from the build in scratch mike, so you have also a reference audio. As you can see in the video above – they come with a programm that takes car of the syncing process, doing all the heavy lifting, while you have a coffee and a smoke.


That’s all pretty cool Frank, but why should I fork out an other few hundred bucks, when my PluralEyes already does the same?

Good question, glad you asked.

First of all, PluralEyes depends only on comparable waveforms. There are a lot of scenarios, when you don’t get those.

Having a dialog scene (lavalier) a few hundred meters away, on a 300mm lens, is one of them. There are many others, but here is one, that already gave me some headaches. Try to sync any raw material with PluralEyes – no dice (at least not for now). Instead editing within Resolve, I have to render out proxies first, sync them in PluralEyes, edit them in Premiere, XML my timeline over to Resolve, render DPX out with final grading, import them back into Premiere, where the audio track sits, andwhatnot. Pretty much a big merry-go-round, and utter waste of time.

Wouldn’t it be nice to have the external audio synced within Resolve after importing the raw material? Actually this works.

But you need a recorder that supplies his own timecode, like a SoundDevices 702T/744T/664 or Tascam HDP2.

Here is how: 

First you jam-sync your Tentacle with the recorder – so the Tentacle reads the timecode the recorder produces.

Than you can jam-sync all you other Tentacle from this master Tentacle and start shooting. When it comes to editing, you import all your video and external audio files into Resolve, select them all, hit “synchronize” – and BAMM you are done. Pretty awesome eh?

Yes Frank, sounds really awesome – any downsides?

Yup, there are downsides, but keep in mind, that I had prototypes for testing – things may still change.

1. The software, that comes with the Tentacles, is Mac only.

2. It doesn’t look like the batteries are user exchangeable, no idea how many cycles they last.

3. You need a recorder, that generates it’s own timecode, when you want to use the Tentacles with Resolve (at least for now).

4. To change anything in the setup (like frame rate or output), you need a computer (there is an app coming though)


all in all, I’m pretty pumped with the idea of a really simple, and affordable device, that fixes one of the biggest problems, I had with the Blackmagic cameras, the lack of syncing them to a recorder.  Also the idea of having raw material synced to external audio within Resolve is nothing but great. IMHO there are several things, that still need to be addressed, like it would be nice to also use recorders that don’t generate timecode for working in Resolve, but otherwise this looks all very promising.


1. the battery should last 3-5 years – a battery change kit (user changeable) will be available. 

2.  You actually can use recording from – let’s say a Zoom recorder (or any other non-TC recorder) – for syncing in Resolve, but you have to put the files through the provided software first (and you need a Mac for this).

Since you are not recording TC as data, but as an audio track, Resolve can’t read it. But since it only reads “real” TC, you have to put the files through the provided software, to generate that “real TC” on you audio files.

UPDATE 2 – Windows transcoding app will be included.

If you use a Zoom, Tascam or any other audio recorder, that doesn’t generate its own timecode, you have to transcode the Audio-TC to BWF before Resolve can use it.
I just got word from TentacleSync, that they will provide a Windows program, that does the transcoding, so that you also can use files from a consumer recorder for quick and easy syncing in Resolve.
If you are on a Mac, you can already do that, with the program they have now.

So if you want this to become a real product, back it on IndyGoGo

2 thoughts on “Syncing external audio with ANY camera and recorder – Tentacle takes the pain out of the butt.

  1. Frank I think this is a great idea, but way over the top in price for a real time clock that you can set the timebase on. I will say this is more sophisticated than that and great if you have equipment set up for time code.
    If your equipment can’t do timecode I would like to see an audio recorder that size or maybe a bit larger. The recorders would be triggered wireless from a master on the camera and record a start and stop code(sound). This code could then be read by software and a xml sync file could be created very much like PluralEyes does. Just think of what all fits into a smartphone. Of course I’m talking about something for the small independent film maker that is shooting with equipment that still thinks it’s a still camera and their best recorder is a Zoom.

    • The concept with the triggered mini recorders you are talking about is quite a different approach. As far as I know, JuicedLink is developing exactly this in the moment.

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