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  • Hey all, just changed over the backend after 15 years I figured time to give it a bit of an update, its probably gonna be a bit weird for most of you and i am sure there is a few bugs to work out but it should kinda work the same as before... hopefully :)

Build 16v3.2.1 sync w/DIVA & 16G CF!

Mark L. Pederson

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Part 1

Earlier this week - we ran a series of tests for a specific project that would be using the DIVA 5 audio recorder with multiple cameras, all needing to have matching TC.

Previously, in our build 15 tests, we found an sync offset so we were anxious to re-test. Here's some notes from our test - I'll break it up over a few posts.

Also, Deanan had sent us prototype 16G CF cards for the Offhollywood team to try to break (we couldn't - and yes, we hammered hard) - so, we thought we would throw that into the mix and shoot takes 9 minutes + with head and tail slates 4K RC36 2:1 + 16x9 to CF.

First, the DIVA, DB and audio cables:

Never worked with the Diva. I called up one of our favorite sound department guys - Brian Miklas - and asked him to come over and play.

Peter Schneider co-owner of Gotham Sound was kind enough to make a "house call" and bring the Diva 5 over and give us all a "Diva for Dummies". If you don't know Gotham Sound, you should. They are the best of the best - the sell and rent gear and provide support to the A-List and Indies alike.

One thing we discovered back when audio appeared on the Red - was that RED's line level input was based on a the philosophy that "line" is voltage based and 0dB Tone is 0.775V RMS - this is the "line is line" philosophy.

The problem with that is, the voltage output of various mixers is going to be slightly different - and folks that send line to HD cameras are just use to sending -20bd tone - check the level on the camera, ADJUST THE LINE LEVEL ON THE CAMERA to match - and go. On the RED, you can't adjust line level input.

We also discovered in earlier tests, when you send a -20db tone to Line on the RED it over-modulates. The cables sent by RED were padded -4db - but our tests indicated what was needed to "nail" -20db tone in - so that it was -20db when extracted - was in fact much closer to -10db.

i am not an audio expert by any means (be nice fellow experts!) - but I know I would rather be UNDER than OVER - and in the real world of field recording - working with only a -4db pad on the Red means you stand a very good chance of over-modulating.

We had Gotham make us -10db pads which we have using on almost all of our shoots.

Now, the funny thing here is - ZAXCOM (makers of the DIVA) have the same exact thinking as RED. The LINE output of the Diva, is in fact, -10db compared to typical recording devices.

So, the first thing we did, was send -20db tone to the RED with NON-PADDED cables. And, as expected, dead on.
 
Part 2

Next, the Synchbox

We wanted to test TC Jam on a syncbox. There are "two usual suspects" in the land of syncboxes that everyone seems to use:

The Ambient Lockit and the Deneke Decode SB-T

I asked for opinions on another thread here on REDUSER and got folks saying they had success with both units. So I asked Peter - he said that although both boxes do the same thing, they are in fact, VERY different "under the hood."

A fundamental difference is that the Ambients need to be "tuned" to match each other with the Clockit Controller (Ambient's master timecode generator) - You do not need to "tune" the Denecke SBT.

So, if you just go and rent a few Ambients, jam them all and go (without tuning to the Clockit Controller) you will most likely have issues.

He felt strongly that the Denecke was better fit. So we did our tests withe Denecke SBT.

Jumping ahead here, we tested WITH the Tri-Level into the Genlock on the RED and WITHOUT - just to see if there was a difference - Peter suspected there would not be because as it's not video tape - the cameras clock should maintain without Tri-Level. Peter's instincts were correct - and we did not see ANY difference with, or without TRI-LEVEL connected.

So, if you are not phasing shutters for 3D, etc. - you can go with the new Denecke SB3 - it has a 5-pin Lemo option, no TriLevel - $500!!

** there is a 5 pin option for the SBT - we just went BNC to the ET BOB.
 
Part 3

Shooting

We wanted to compare the audio that was single system (teathered to camera from Line out of Diva) to the actual WAV file the Diva recorder.

We still had the ET handheld proto - so before sending it back to ET - Eric Camp, our Director of Camera Operations, (Eric is the guy the went around the world with Claudio Miranda shooting with our REDs in five countries - more on that soon - and he techs our higher profile stuff and trains our techs and keeps our little babies clean and mean) he is truly a Red rockstar.

Eric shot full 16G takes on the new CF cards - handheld - walk and talks with one of our interns chatting away around Soho and Little Italy. When the Edge code hit 9 minutes he'd call for the tail slate and Peter would jump in and tail slate.

We fed the TC from the Diva to the Denecke - jammed - and disconnected the TC.

(notice the construction - YES we are building!)
 
Mark,

This is outstanding. I thank you for being so generous with the community and sharing all of your results.

It's a big help.

David
 
Part 4

The Results

We offloaded the media from the CFs and the Diva. Besides the DVDram - the Diva has a FW400 port - you plug a drive it - it formats FAT32 and transfers the files - SUPER SLICK.

Also, the DIVA records it's "raw" audio in a proprietary file format and does not "process" into files until you tell it to. (the DIVA records one file every time you start and stop)

So, you can select how many tracks, and other options after doing all your recording. Even create different outputs from the "raw audio master".

I kept thinking - this thing (the Diva) is the "RED" of hard disc audio recorders!

I loaded the QT wrappers into FCP - loaded the WAV files.

Dragged a shot into the timeline.

In the Bin, I highlight the QT, highlight the WAV file that matches the clip - right click - "merge clips" - select "timecode" in the pop-up window - and BANG new merged clip.

I turned on the waveforms, to compare in-camera audio (hard fed to Red via LINE) to the Diva audio -

I scrubbed to the tail slate - and I there she was. Frame accurate. On every take we shot. And the audio is PRISTINE.

We are always testing stuff here, and I'll try to share more of these things as time permits.

I want to thank Peter from GOTHAM SOUND and Brian Miklas for popping over and helping do the tests - I am totally sold on the Denecke, and the DIVA. It plays nice with RED.
 
Thanks for the great testing. Anybody do something similar with any Sound Devices equipment?
 
Thanks for taking the time to do the test and sharing. Used the same set up for RED, Cantar and SB-T, had good results too. Video post said sync was good.
 
what was the audio quality comparison between the Diva audio and Direct to RED Line IN baked?

I'll dig into the waveforms next week - but the Line sounded amazing - the waveforms really look identical.

I'll give the files to "audio snob" and report back -
 
great!
we're starting a feature in 2 weeks and planned on recording directly to the cam as we have always done.
we get great consistent results but its always nice to see options and how they stack up.
Plus we're shooting the feature in Build 16. very excited lots of available light shooting and alot at twilight and nighttime in nyc
 
great!
we're starting a feature in 2 weeks and planned on recording directly to the cam as we have always done.
we get great consistent results but its always nice to see options and how they stack up.
Plus we're shooting the feature in Build 16. very excited lots of available light shooting and alot at twilight and nighttime in nyc

16v3.2.1 rock solid for us. LOVE it.
 
I am very happy to see the Deva output level exactly match the Red camera. We developed the Deva to be a very flexable mutitrack mixer/recorder.

I hope its capabilities are a very good match for the Red camera. The Deva has a wide choice of time code and sample rate options that should make it compatable with any production environment. Up to 16 tracks are available with Deva 16.

Time code offset and audio delay in single sample increments have now been added to the Deva for perfect sync in any situation.

I am now a member of this forum and will look in from time to time to answer as many audio questions as I can.

Glenn Sanders
President Zaxcom Inc. (AKA The Deva people)
 
I am very happy to see the Deva output level exactly match the Red camera. We developed the Deva to be a very flexable mutitrack mixer/recorder.

I hope its capabilities are a very good match for the Red camera. The Deva has a wide choice of time code and sample rate options that should make it compatable with any production environment. Up to 16 tracks are available with Deva 16.

Time code offset and audio delay in single sample increments have now been added to the Deva for perfect sync in any situation.

I am now a member of this forum and will look in from time to time to answer as many audio questions as I can.

Glenn Sanders
President Zaxcom Inc. (AKA The Deva people)

Glenn, i was trying to get a quote to buy one Diva quite urgently for a shoot. My usual A/V contact in CA could not get his local distributor to respond. Who should we contact to get one to Singapore. Lim
 
Part 3

Shooting

We fed the TC from the Diva to the Denecke - jammed - and disconnected the TC.

(notice the construction - YES we are building!)

Mark L Pederson, I am not an audio person so is a little confused here. You explained earlier that unless if there a need to do video sync say a 3D, there is really not need to use the tri-cycle. Your connection will be to feed the TC from the Diva to the Denecke SB-3 - where?, which is connected to the Genlock using the BNC out instead of TC in on the camera using the lemo version? and then jammed them together? and then disconnect the TC - from where - connection from the Diva to the Denecke?

Appreciate if you can elaborate more on this - Lim
 
Glenn, i was trying to get a quote to buy one Diva quite urgently for a shoot. My usual A/V contact in CA could not get his local distributor to respond. Who should we contact to get one to Singapore. Lim


We have a few dealers in Asia that are listed on our Web site. If you can not find a suitable dealer call or Email Colleen at Zaxcom.com and she can help.

Glenn
 
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