Qlab and quad

[Jay Ashworth]

For the first time in my 8 years or so back in the theater, somebody is asking me to play quadraphonic audio out of qlab. 4.6 in this case. I know that requires an audio license, but I'm not quite sure what format of file qlab will be able to pull four tracks of audio out of as I import it and drop it in a cue sheet. Anybody know that particular thing off hand, or have a pointer to a good write up on using Qlab specifically for quad?

The last time I touched quadraphonic audio was when my dad had a quad 8-track player when I was 12.

 

[aeh20s]

According to this: https://qlab.app/cookbook/mixing-stems/ if you have a wav with embedded multi-track then Qlab can recognize and extract each channel natively. Then you just have to have the infrastructure to split it out.

 

[Jay Ashworth]

According to this: https://qlab.app/cookbook/mixing-stems/ if you have a wav with embedded multi-track then Qlab can recognize and extract each channel natively. Then you just have to have the infrastructure to split it out.

Yeah the stuff Downstream is no problem in this room. I just wasn't aware you could put four tracks in a wave file. I'll give that a try with audacity and see what it thinks. Thanks. I always forget about the cookbook.

 

[Jay Ashworth]

Now that I'm back out of bed from my latest booster, I located this page

Multichannel Audio Channel Allocation Test File

If you’re needing to check the channel allocation of a multichannel audio file player, this file (multichannel_wav_channel_id_5_1 – remember, right-click to download…) might come …

www.tonmeister.ca

which has a 6-channel WAV file for testing 5.1 audio, which Audacity, at least, loads fine. Now to see what QLab does with it...

 

[Jay Ashworth]

QLab thinks it's stereo. Hmmm... (4.6.10, though I don't think that's pertinent...)

 

[aeh20s]

I have a theory that you need to have your cue set to a multichannel output to get all the channels listed. I'm attempting to test that theory but when I tell my aged MacBook Air to switch to my multichannel output device it beach balls.

 

[Jay Ashworth]

I have a theory that you need to have your cue set to a multichannel output to get all the channels listed. I'm attempting to test that theory but when I tell my aged MacBook Air to switch to my multichannel output device it beach balls.

You mean the default audio cue in settings? I'll give that a try. The interface is a PreSonus 8x8, but we almost never use all the channels, so it wouldn't surprise me that that's not the default. I didn't get an error, or a crash, it just loaded it and pretended it was stereo Dash there were only two volume control columns in the matrix.

 

[aeh20s]

You mean the default audio cue in settings? I'll give that a try. The interface is a PreSonus 8x8, but we almost never use all the channels, so it wouldn't surprise me that that's not the default. I didn't get an error, or a crash, it just loaded it and pretended it was stereo Dash there were only two volume control columns in the matrix.

Or under the output patch in the "audio levels" tab in the cue. Upon further search you also need a license for more than two channels of audio, which I don't have.

 

[Jay Ashworth]

Or under the output patch in the "audio levels" tab in the cue. Upon further search you also need a license for more than two channels of audio, which I don't have.

Well I knew you need a license for more than two channels, but it has also been my experience that you can build a cue sheet that requires a license and test it, and even save it, you just can't reload it and have it work until you put the license on. So that was what I expected here: I expected it to read the file, see 4 tracks of audio -- well, six ;-) -- and show it to me as a 6-track audio cue.

 

[aeh20s]

Well I knew you need a license for more than two channels, but it has also been my experience that you can build a cue sheet that requires a license and test it, and even save it, you just can't reload it and have it work until you put the license on. So that was what I expected here: I expected it to read the file, see 4 tracks of audio -- well, six ;-) -- and show it to me as a 6-track audio cue.

That was my expectation as well. If I get bored tomorrow when I'm back in the office I may rent a 24-hour license just to see. Otherwise, I wish you good luck Jay.

 

[Jay Ashworth]

That was my expectation as well. If I get bored tomorrow when I'm back in the office I may rent a 24-hour license just to see. Otherwise, I wish you good luck Jay.

Well, only if you want to -- by tomorrow I'll probably be doing the same thing.

 

[dmx]

The shortest answer is yes. QLab will recognize multi-track audio files and automatically assign 1:1 patching (ie. track 1 to output 1) by default.... but...... it will by default ignore channels that do not have an output assigned. When playing the aforementioned file without an audio interface attached, it will only display tracks 1&2 as live. You can overcome this by patching channels beyond 1&2 to outputs 1&2.

Tested using QLab 5. Screenshots attached. Also, in the I/O tab you should be able to see the way that QLab recognizes the file.

Edit: Should have mentioned that this was accomplished using the licensed version for audio/video. The video portion should have no change on the outcome.

-Matt

 

[Sam Kusnetz]

QLab will recognize multitrack WAV, AIFF, and CAF files up to 24 channels by default, no adjustment to settings required, as long as you have an audio license installed.

when you set a multitrack audio file as the target of an audio cue, the levels tab in the inspector will show one row for each track in the target file.

if the levels tab for your cue is not showing the right number of rows, you either have an incompatible file or are in need of installing a license.

i am away from my mac at the moment so i can’t test, but it’s possible that multitrack audio file support is one of the licensed features that you cannot test without a license installed.

also, please note that in QLab 5, we’ve replaced this testing behavior with a more sophisticated demo mode. we did this because many people seemed to be confused by the testing behavior and would end up in a day-of-show panic.

 

[Jay Ashworth]

Correct: even though my Audio Levels tab shows "10" for the number of visible channels, I have to switch the Audio Output Patch to my Presonus *and* click the Edit button to turn up the channel count... and that's when I crash into the License requirement.

My issue was that I hadn't realized you could *put* more than 2 channels in a WAV file.

I'm sufficiently confident in the process, though, to invest the whole... 4 bucks, to test that.

(I've been fronting the license money for a couple years for anyone whose shows actually needed it, secure in the knowledge that I get a full license out of it in the end... )

 

[Jay Ashworth]

Funny sidebar: the guy who writes the blog I lifted that test track from...

is the final checkout guy at B&O on bespoke turntables with, probably, scale-4 prices.

And elsewhere in that blog is an archive of Hi Fidelity magazine, all the way through it's absorption into Stereo Review in 1989. Y'know, if you're into that sort of thing...

 

[Sam Kusnetz]

Cool.

The "visible channels" control refers to the number of visible cue outputs, which is a separate thing from the number of channels in the target audio file.

An audio license is required both for using more than two cue outputs AND for using cues which target audio files containing more than two channels.

 

[Jay Ashworth]

I'm starting to fall off the object nomenclature wagon here...

By "cue outputs" you mean "the number of audio tracks in an audio cue, here, '6'"... no, you then immediately say it's not that.

What's a "cue output", Sam?

 

[Sam Kusnetz]

cue outputs are the columns of the mixer in the levels tab of the inspector.

an audio cue targets an audio file, and that file can contain one to 24 channels or tracks of audio. those channels/tracks appear in the levels tab as rows in the mixer; each row represents one channel/track. you use the crosspoints in the mixer to route each channel/track to one or more cue outputs.

in workspace settings > audio, if you have an audio license installed, you can click the "Edit..." button next to an audio patch which opens the audio patch editor. there, in the routing tab, cue outputs appear as rows and device outputs appear as columns. device outputs are the outputs presented to qlab by the audio device. so you may be using dante virtual soundcard and have 64 device outputs, or you may be using your headphone jack and have two device outputs. each cue output can be routed to device outputs as you like. the default routing is 1-to-1, so that cue output #1 feeds device output #1 and so on.

 

[Jay Ashworth]

Well that sure is a lot of words to say "RTFM".

Thanks. So if you don't have a license, you can put a multitrack cue in a sheet, but you can only get to tracks 1 and 2 of it, for 2 separate reasons. Got it.

 

[Sam Kusnetz]

that's correct, and happy to help!

since you were asking about nomenclature, though:

Thanks. So if you don't have a license, you can put a multitrack cue [an audio cue] which targets a multitrack audio file in a sheet [cue list or cart], but you can only get to tracks 1 and 2 of it, for 2 separate reasons. Got it.​