Production Switchers

Ross Carbonite 2M, HD 1080i 59.94.

I have some audio issues that seem to be related to what I am switching on the Carbonite. I have some more troubleshooting to do, but I thought I would throw this out there for any ideas.

PGM is routed out of the Carbonite to an AJA HD10 which embeds analog audio to the SDI video signal. The AJA box feeds an Extron Matrix router. The router is patched (internally) to a BMD Hyperdeck Studio for recording and to a Vidiu box for the Livestream.

1) I have a 2 box set up on ME1 reentered into ME2. When I take ME1 to PGM, we get a loud pop in the audio in the BMD recording, but not on the Livestream. Same when switching away from the same effect from ME1.

2) However, the Livestream has repeating short audio dropouts under the same switching setup as #1 above - only when the switcher is on the 2 box effect on ME1 reentered to ME2.

Might this be related to power distribution to the various devices (some sort of grounding issue? Dirty power?) Or is the Carbonite actually creating the audio pop and sending it out via SDI?

Thanks in advance for any ideas.

- Rich Ford

Huntington University, IN

Hi Rich,

Carbonite does not perform clean audio switches or transitions, it has no audio processing but is simply a pass through for embedded audio. If you switch between input streams the audio will most likely be interrupted briefly and give rise to the pops and clicks you are hearing.

For clean audio switching you really need to manage audio via an external audio switcher/mixer.

Nigel

#Carbonite

Looks like from Rich's description the audio embedding IS happening down stream of the switcher so it is not a Carbonite Audio issue but a Carbonite SDI stream issue.

I have had this issue with the Vision where there is something different in the SDI 1s and 0s that makes devices downstream glitch when switching sources.

Sounds like an ancillary data thing or some kind of timing weirdness when you take the boxes on PGM.

#Carbonite

Hi again, If the embedding is being done downstream then turn off the Ancilliary data pass through. We have seen a number of devices that are sensitive to ANC data switches (the SDI data out of Carbonite and Vision is fully compliant with SMPTE standards BTW). Now downstream devices shouldn't be affected by ANC data changes, but we have found some that are - particularly some projection systems.

An easy test is to set it to strip anc data. MENU > SYSTEM > NEXT then use the Anclry knob to select N Strp or L Strp if there are still issues when set to N Strp try L Strp. One of these will resolve the issues if its downstream devices that are unhappy. The same applies in Vision also BTW.

Nigel.

#Carbonite

Thanks for your replies.

Paul is right; analog audio from our mixer is embedded downstream of the switcher. So I will try turning off the Ancillary data pass through. I should have time to try this tomorrow, and I will report back.

- Rich

#Carbonite

Just adding a little more here -- Sometimes the embedders are able to have a auto pass through type option. So basically if it sees some data it allows it to pass. In the embedder you can sometimes set an option there that will allow it to Strip and replace the incoming VANC as well.

Les

#Carbonite

Bingo. While changing dip switches on the embedder to strip VANC didn't work, changing the switcher's Ancillary Mode to "NSTRIP" did the job (I used the dashboard to do this) - no more livestream dropouts, no more pops on the BMD Hyperdeck recordings. Thanks Les & Nigel for the help!

#Carbonite