ALT Audio through Cinema Processor?

[Ryan Gallagher]

We have a "film festival" Friday/Saturday that due to cue complexity and how the content was provided, is being driven from a playback and graphics laptops backstage. It is really more of a presentation/speaking event with a few blocks of film content mixed in.

Normally in this setup we only use the Live PA, but as it contains some actual FILM (albeit stereo near field mixes), I'm tempted to send audio up to the booth to attempt to get at least the screen L+R channels in use for those program portions.

What would be best practice on an AP20? route it into the non-sync or non-sync matrix inputs via our little mixer that already feeds those inputs (and put the mixer at unity gains)? Being "non-sync" it is not really intended for video+audio. The other option would be to see if we can insert the L+R XLRs at the patch bays to the analog inputs so that the corresponding preset can be utilized (I think it would actually be our CP650 preset)? But my visual memory of that option is not as 100% doable.

I'm aware there may be some sync issues, but my playback software has an audio delay feature I could deploy.

I'm bringing DCP conversions too, but the day is perhaps not scheduled with adequate time to get them ingested before run through rehearsals begin. I also shudder at the thought of controlling the projector via VNC from stage, which would be required for the DCPs. Generally too much content not received early enough to go an ALL DCP operated from booth route.

[Ryan Gallagher]

A more robust approach that involves gear we don't own, would probably be to accommodate 5.1 ALT by sending audio out of the laptop over hdmi and disembedding a 2.0 mixdown for the Live PA, then letting the full mix carry on down the SDI chain and get converted back to HDMI for a digital input on the AP20. We are like 1 sdi to hdmi box short of using that approach, and none of our content is 5.1 anyhoo. I'm also not sure our playback software can output 5.1.

[Carsten Kurz]

I do this type of event from a Mac or Windows laptop and feed audio and image through HDMI to the AP20. Depending on source material, I pass-through 5.1, or, if stereo sound is delivered, I use the AP20's DTS Neo:6 upmixer with it's cinema preset, which serves the main purpose of creating a center dialogue. We have multiple HDMI connection methods from the auditorium or stage to the booth.
Most of the content we show this way only carries stereo audio. Both Mac and Windows machines will typically default to stereo LPCM over HDMI, but may be configured for multichannel if necessary. The AP20 will only upmix a stereo signal with Neo:6.

I sometimes use VLC for playback and actually use the embedded live audio EQ of VLC to do some on-the-fly adjustments, as many of these audio mixes have been created using headphones or built-in monitor- or laptop-speakers, and their creators often have no idea what the actual spectrum of their audio tracks does contain. This is an easy way to eq or soften audio that is transmitted digitally over HDMI.
If you output analog audio, you could of course do similar things with a basic analog mixer. An analog audio mixer would also serve balanced analog audio towards the booth.

I would use the live PA for mic/talks.

[Ryan Gallagher]

In the heat of the hurried setup and reh schedule, we went with the non-sync input passing through the booth mixer at unity. I sent that stereo pair to FOH first so they could have it for the non-film clips, then routed to booth.

the DTS neo is a good tip, will have to play with our other options that involve routing the fully capable mix or digital signal paths, but was not needed on this one.

i tried our non-sync matrix (which we never use) to get center and LFE involved, but it needs some levels and EQ love, was mostly outputting C+L, failed back to L+R only, no time to diagnose.

Can’t say I want to do this frequently, with 100 assets, 50 of them videos (for just the awards show). But at least we can!