I’ve had another Video Production Idea: An SDI Multi-Core for Audio

I Think I May Need Help To Find Out If My Theory Works from @blackmagic_news

Future Jim Note:
Since Writing this post have done a bit of research into Dante and what the price difference between the setup bellow and a Dante system would be. Check out tomorrows post to have a look at my findings.

So I had a bit of a shower thought the other day. How much would it cost for me to bring audio from a venues sound desk to my future Video Production System? Now me being me I don’t just want the main Left and Right audio from the sound desk. I’d like a few separate mixes for example if I’m shooting a concert I’d like the Drum Kit on one channel the bassist on another, guitarist on another and so on.

You may be wondering why I would want something like this. When I’ve previously streamed live events I’ve taken left and right feeds from the venues sound desk and been stuck with what I get. This could sound absolutely amazing in the venue but you the vocals could be overpowered by the instruments or the sound engineer leaves music running that can be heard on your stream even though it’s not planing in your venue. By having the ability to create a separate you can make sure that you live stream or recording sound as it should for your client.

There are two ways to get the audio from the venue. I can either split the audio before it gets to the mixing desk using microphone signal splitters or if the venue has a mixing desk with enough outputs, I could use the spare outputs on the venues mixing desk.

Now, as I’ll be basing this around my previous ATEM Mini Pro setup I’m going with the second option as It would complicate my idea unnecessary and would require me to bring everything from the stage to a mix point and then out to the rest of my setup. Why complicate things when that’s already happened at the venues audio desk.

Anyway, on to my idea. Did you know that SDI can carry 16 channels of audio? I did but I had no idea how to utilise it, as none of the Blackmagic ATEM Switchers allows you to input a single SDI and control each of the 16 audio channels only the first 2. The other problem I came across is that I haven’t been able to find a device that will take 16 XLR inputs and convert them to a single SDI output. I have come up with a workaround though.

Black magic produces a couple of devices that either take in 4 audio feeds and convert them to SDI or take SDI and break out to 4 Audio feeds. You can use four of these together giving you sixteen channels of audio over a single SDI cable. So I’ve come up with a rough idea of how I can use them with my ATEM Mini Pro setup idea. It looks a bit like this:

If I could I’d remove a lot of the cabling by using Blackmagic’s Micro Converter at each camera so I only had to do a simple run to each camera and have the jumble of cables at the switcher. Unfortunately, that doesn’t work as an HDMI to SDI converters strip out the ATEM Mini Pro’s camera controller ability, otherwise, I could have a small rack at the switcher that had all the Audio to SDI bit’s in and made everyone’s body life a bit easier.

The thing I’m not sure of though is wether or not I have to have the audio flow in one direction. For example, I have an Audio to SDI converter at the switcher so I can send any VT audio over the SDI to the in house audio engineer (that comes from a HDMI Audio splitter as the ATEM Mini Pro doesn’t have an audio out). I’m not sure if the audio can only travel in one direction or as it would be possible to pick up or insert the audio from any point on SDI run.

If the audio can run in only one direction I have come up with this plan where everything coming from the Audio mixer goes into the rack mountable Audio to SDI converters then to an SDI distributor via the “SDI Multicore” and then out to the cameras. I’ve also added an extra 4 SDI to Audio converters so I have 4 channels to go to the ATEM and an extra 4 that can be sent elsewhere if need be. (I’ve just realeised that the HDMI to SDI Converter that I added should have actually been an Audio to SDI device so I can send the audio from any external video to the audio mixer.)

As I said earlier it would be great if Blackmagic or someone else made a device that you could put 16 audio channels at one end and another to take them all out at the other end. Or even a mix of say 12 in and 4 out or 8 in and 8 out. This way audio could easily be shared from one department to another. Another option would be to add an extra SDI port onto the switchers that are an audio-only interface that works with Fairlight audio engine built into the ATEM switchers.

Side Note

I’d love it if they also made a version of the Fairlight(v console that had SDI audio inputs. I’d have no qualms about recommending one to venues if the was a 16 channel stage box that ran it’s audio to the console via SDI. Imagine the time and money that would save in cabling. As I lighting Technician too I’d be interested to see what they could do when it comes to lighting control. They’ve nail Video and Audio (even if they don’t do live products… yet?) Why leave out lighting? Imagine being able to run all of your venue with the products of one amazing company knowing they would all be able to work together to put on the most amazing live events

I suppose I could probably do everything I’ve mentioned with fibre and ethernet using Dante Audio stage boxes and other such things but again I’m left with the problem of the ATEM not having a way of putting the audio feeds straight into the Fairlight engine on the ATEM.

Do you like to have a separate audio mix for your productions? What solutions do you use? What would you change in my master plan? Let me know in the comments below.