Tentacle Sync Timecode Generator – perfect in-camera audio synchronization – Quick review

We already reported about it in a recent news post (click here) – Tentacle Sync is a small black box (about the size and shape of a LP-E6 Canon battery which you might be familiar with from the 5D and 7D) which attaches to your camera and audio recorder and generates timecode. 

Now the guys behind the Indiegogo campaign and the product itself gave us a chance to use their prototypes and take them for a spin on a shoot. And I have to say, I’m thoroughly impressed.

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Syncing video and audio has been an important issue for mid-range to semi-pro shooters ever since DSLRs became commonplace, due to their lack to professional audio inputs. We started recording sound on external audio recorders, but that brought the problem of syncing audio in post with it. A brilliant software called Pluraleyes (now owned and developed by Red Giant, the makers of the legendary Magic Bullet Suite) made our lives much easier by analyzing and comparing waveforms, and thereby syncing the audio tracks easily and in a very straightforward way, ready to be edited in the NLE system of your choice.

However, of course Pluraleyes has its limit. Sometimes the camera is so far away from the action that its internal microphone doesn’t pick up what the audio recorder is picking up (and actually isn’t supposed to), which means there is no corresponding audio track to sync. The same is true for multi-camera shoots at events. It happened to me before that Pluraleyes thought it had recognized similarities and synced tracks up, but in reality it’s completely off because it might have used the wrong refrain of a music track played in the background as a reference. You can’t blame it really, it’s still an amazing piece of software that makes our lives so much easier, but it clearly has its limits.

If you work in traditional broadcast TV environments from time to time like I do, you might be familiar with Ambient Recording’s LockIt devices, which are made for larger broadcast cameras, feeding a timecode signal into the cameras which is in sync with the one generated for the external audio recorder. So it’s almost the same thing for a much higher price and with a considerably larger footprint similiar to a pack of cigarettes – so hardly feasible for everyday indie productions. Several times before I had issues attaching a LockIt to my C300, ending up with velcro-ing it onto the top grip, which is far from ideal and limits how I can use the camera.

 

Test set-up

The Tentacles are tiny – so tiny in fact that you can attach them even to small cameras like the A7s easily. And that’s exactly what I ended up doing. When testing, I gave it a quick go with an audio recorder, connecting one of the Tentacles with the supplied mini jack to XLR cable, while the other XLR track of my Tascam DR-100 recorded from an external Røde NTG-3 microphone. Before that, you have to do a quick and easy sync run between the Tenticles by connecting them to each other with the supplied cable, pressing the one button until the green lights flash in unison. Very easy and straightforward.

Trying to mimic a typical production, I let the audio track run through for about 30 minutes, while I collected a lot of different shots with the Sony A7s, which had the other Tentacle attached to it simply via a mini jack cable into the microphone input port.

This is a very realistic scenario and exactly where I had problems with Pluraleyes before: a multi-cam event shoot with an audio recorder at a central position, recording a wild track of the event on one channel, and possibly the audio from the stage on on two other channels – maybe one camera in a fixed wide position filming the stage, while I’m on the other, smaller camera, catching close-ups from the stage performance as well as quick reaction shots from the audience.

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When I mimicked this scenario, the Tentacles worked great – I used their supplied software to sync up audio with the image, and then getting an XML that can be imported into Final Cut Pro X. Alternatively you can also export the clips with attached audio tracks, which makes you entirely independent of what editing system you use – or, say, to hand off footage files to another person to edit, without giving them the hassle of syncing.

Now it should be added that the SMPTE timecode signal embedded into the audio track which is generated by the Tentacles is industry standard – that means you don’t have to use their software – it’s totally optional. You can still sync timecodes in the editing application.

For peace of mind, the Tentacles also have a reference mic build in. I guess that’s really just for extreme emergencies though, because I can’t really think of many occasions where you might need it when you have proper timecode – only if another Tentacle fails to work, I guess, you can still sync via Pluraleyes with the reference sound.

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Conclusion

There’s not much more to say about the Tentacles than they just work. The guys behind these devices show a rare ability to think of easy solutions that work well both in hardware and their software – probably because they all come from video production as well. I’m looking forward for their software to support even more codecs and multicam exports better, but it’s already very well matured. It’s definitely very close to market, something you can’t say about most crowd funding campaigns for hardware …

I can recommend Tentacle Sync to anyone who regularly records image and sound separately on set. It’s just a no-brainer with these boxes, without the need for clapperboards and a lot of hassle in post production.

Last but not least, it’s predominantly sound people who know the matter best – of course, it’s their business. The guys behind soundrolling.com interviewed Max and Ulrich from Tentacle Sync extensively, asking all the right questions about the product – check out the recording of the YouTube Q&A by clicking here (unfortunately it can’t be embedded).

You can preorder Tentacle Sync on Indiegogo now.

Hands On Tentacle Sync – Hardware – Part 1/2 from Tentacle Sync on Vimeo.

Hands On Tentacle Sync – Software – Part 2/2 from Tentacle Sync on Vimeo.

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Joachim Richter Reply
Joachim Richter November 27, 2014

Windows is currently not planed. Why not?

Reply
Erik December 13, 2014

Does this system prevent audio drift (like genlock) with longer recording times (over on hour)? Or does it simply add a synchronized mark at the beginning of the recording?

Ed David Reply
Ed David December 22, 2014

Sounds like a great idea, but I’m not interested until the product is available and has been reviewed.