4 channels audio over radio camera on OB

[Lancashire soundie]

I need an answer for a question which may come up soon.  Possibly up to 4 presenters on handheld stick mics, feeding 2 radio receivers on the back of an RF camera on an OB.  Is it possible to feed those 4 channels into the camera (no, I don't know the camera model yet) and have them fed over the digilink via SDI, to the truck, so the audio mixer can control the levels independently?

 

Or I give the audio assistant following the RF cameraman a simple mixer and 4 channels of radio, and have him mix them and give the camera a mono feed.

[daniel]

Out of curiosity, "up to 4 presenters on handheld stick mics, feeding 2 radio receivers" - 2 x dual channel RX into a 4 channel camera or something else?

[VAS]

Make sure, SDI can transport 4 channels of audio and not two. Is this what you ask?

[Lancashire soundie]

AFAIK SDI can cover 16 channels, but my question is more about getting the audio into the camera/transmitter.

[ryanpeds]

You could consider bypassing the camera and feeding the audio using an SDI audio embedder after it comes out of the camera

[Shastapete]

It depends on the camera, or as ryanpeds suggested, embed the audio into the sdi stream after it comes out of the camera before it hits the transmitter. There's a box from Blackmagic design that can do it. $300

 

https://www.blackmagicdesign.com/products/miniconverters/techspecs/W-CONM-05

[Lancashire soundie]

Brilliant, thanks guys.  I'll bookmark that little box in case it comes up.  I'm just hedging bets at the moment, trying to get production interested in having 4 radio sticks instead of 2 [ugly] wired mics shared between 3-4 people.

[chrisnewton]

Thanks for this interesting thread. questions: if the link from camera to the truck is wireless, how would you go about inserting the 4 audio tracks into the Black Magic box? you would still need either a wireless AES link (times two for 4 tracks), or 4 analog feeds into the box. Maybe you'll get lucky and the camera will have the appropriate inputs on board. The Black Magic box would work, but might get a bit clunky in practice as it will require 12v DC and uses 1/4" TRS inputs to complicate things. Because the box is post video processing coming out of the camera,there would be no delay/offset for sync. Direct input to camera, bypassing the box would obviously be a simpler workflow.

[Paul Katzman]

If it’s a camera with AES inputs (Sony F5/F55, Arri Amira, etc) you can feed it 4 channels. Sticking 2 SRc units on there would be unwieldy, but would work with their AES backplates. I’ve fed 4 channels into an F5 several times, hard lined via a 633 with no issues. And SDI can carry up to 8 audio channels, for what it’s worth. 

[Derek H]

I’d say keep it simple.  Feed the camera good sound whether that’s a good mix on one or two tracks or four discrete iso tracks and it will travel along with the picture however they send it. 

[Eric]

Lectrosonics D4 can send 4 channels of audio. RX can output analog or AES.

I have been using this as a camera hop for a number of years (when not using a G3 scratch track). Likely some are familiar with it and some are not. 

It has it's pros and cons (which I won't get into), but can be helpful in the odd 4 channel send situation.

https://www.lectrosonics.com/US/Digital-Wireless-System/category.html

[PCMsoundie]

On 11/10/2018 at 1:10 PM, Paul Katzman said:

If it’s a camera with AES inputs (Sony F5/F55, Arri Amira, etc) you can feed it 4 channels. Sticking 2 SRc units on there would be unwieldy, but would work with their AES backplates. I’ve fed 4 channels into an F5 several times, hard lined via a 633 with no issues. And SDI can carry up to 8 audio channels, for what it’s worth. 

I've also done this half a dozen times. Sony PDW-F800, F55, Amira. Using SD633, 552, 788T, 688 units.

HD-SDI carries 16 channels of AES.

The most I've seen available is 8 channels using a VCR such as a Sony  PMW-1000 XDCAM SxS Memory Recording Deck but that is really just displaying 8 channels on playback. For AES digital in it is usually just 4 channels on camera, VDRs, if you use an audio embedder it will take up to 16 but you may require 2 embedder units to add audio to 16 channels since each one can only add 8 channels. Some really expensive units allow access to 16 channels of AES input on 8 BNCs such as AJA FS-1 frame synchonizer.