What is the easiest way to make an audio cross fade?

[Jennifer Gillmor]

http://figure53.com/docs/qlab/v3/howto/crossfade-sounds/

These instructiona for making a crossfade seem a lot more tedious than what I vaguely remember from my last QLab job. That was 3 years ago with QLab 3 so my memory is failing me. I'm now using QLab 4.

I vaguely recall a method which had a lot to do with putting the Master Levels up and Channel Levels down on one cue and the opposite with the other. Does this ring a bell?

What is the way you find it easiest to make audio cross fades?

I'm in the thick of a big sound design gig for Canadian Stage and am in a little over my head with QLab. Any assistance would be much appreciate as I muddle through!

[micpool]

You rarely need to use the 'set audio levels from target' (QLab 4) or the copy levels and paste levels steps described in the howto you linked to.

Unless you are changing the routing of the sounds to your outputs with a fade you only need to concern yourself with the master fader in the fade cue. As long as the masters are the only yellow items in the fade cues all the other slider levels(greyed) are irrelevant.

The V and S cues are your friend here as they will allow you  to start and stop cues for plotting without advancing to the next cue, so you have the right set of faders immediately available.

A few  other things will make your life much easier. Unless you are using 24 track wavs routed to 24 desk inputs the default cue routing matrix is not very useful for your purpose. If you create your default routing so that it routes stereo files to all sliders, you will never have to think about the cue matrixes again unless you are doing something specific,  Full details are here:

https://qlabcookbook.com/1999/01/16/better-by-default/

In some circumstances it is easier to fade in a cue by drawing it  using the integrated fade in the Time& Loops inspector tab of the audio cue. That way you can have all your sounds with a natural sounding fade in programmed when required without worrying about using specific fade cues to bring them in (Think of it like attack on a sampler). If you do this then a crossfade is really only a matter of fading the currently playing sound out. This won't work though when you need to loop the entire sound as the fade portion will repeat each loop iteration.

If you are using a licensed copy of QLab then scripts can speed up the creation of fades and crossfades by a factor of 10.

If you put this Rich Walsh Script  in a script cue 

set userDuration to 10

set userMinVolume to -70

-- Set what level you mean by "faded out" (you can adjust this to match the workspace "Min Volume Limit" if necessary)

tell front workspace

try -- This protects against no selection (can't get last item of (selected as list))

set originalCue to last item of (selected as list)

set originalCueType to q type of originalCue

if originalCueType is in {"Group", "Audio", "Mic", "Video"} then

make type "Fade"

set newCue to last item of (selected as list)

set cue target of newCue to originalCue

set duration of newCue to userDuration

newCue setLevel row 0 column 0 db userMinVolume

if originalCueType is not "Video" then

set stop target when done of newCue to true

end if

set q name of newCue to "Fade out: " & q list name of originalCue

else if originalCueType is "Fade" then

set originalCueTarget to cue target of originalCue

make type "Fade"

set newCue to last item of (selected as list)

set cue target of newCue to originalCueTarget

set duration of newCue to userDuration

newCue setLevel row 0 column 0 db userMinVolume

if q type of originalCueTarget is not "Video" then

set stop target when done of newCue to true

end if

set q name of newCue to "Fade out: " & q list name of originalCueTarget

end if

end try

end tell

and set a key  trigger e.g control-F for that cue, you can just select a cue, press control-F,  and a fade cue will magically appear under the audio cue already set up. You can then drag this cue to wherever you need it in your cue list.

Mic

[micpool]

Attached is a demo workspace showing how all the above works

In the cue templates the audio defaults are set so new cues will be created like this for a rig with 2 Mains 2 Upstage speakers and 2 Mono FX spot speakers, and assuming stereo files are the most common in your show.

The first example uses fades, to build  in a music cue on the main speakers , crossfade to a sea on the stage speakers and then fade the sea out.

The second example is the same but  uses an integrated fade on the sea cue to fade it in. Note the position of the loop slice after the fade to avoid the fade repeating.

Also look at the fade in curve shape on the music cue.

The workspace includes the script to create a fade (in a separate cue list called scripts). You can try it out with the cue at the bottom of the main cue list

So you will hear all the cues even if listening on a computers internal audio, the  audio patch 1 device routing matrix is set  so the sounds routed to what will be the upstage speakers can be heard on your audio output like this:

When you use the workspace with an interface and multiple speakers click reset to defaults  to set the device routing back to the standard 1 to 1 device routing set up.

Mic

On Friday, March 30, 2018 at 11:08:41 AM UTC+1, micpool wrote:

You rarely need to use the 'set audio levels from target' (QLab 4) or the copy levels and paste levels steps described in the howto you linked to.

Unless you are changing the routing of the sounds to your outputs with a fade you only need to concern yourself with the master fader in the fade cue. As long as the masters are the only yellow items in the fade cues all the other slider levels(greyed) are irrelevant.

The V and S cues are your friend here as they will allow you  to start and stop cues for plotting without advancing to the next cue, so you have the right set of faders immediately available.

A few  other things will make your life much easier. Unless you are using 24 track wavs routed to 24 desk inputs the default cue routing matrix is not very useful for your purpose. If you create your default routing so that it routes stereo files to all sliders, you will never have to think about the cue matrixes again unless you are doing something specific,  Full details are here:

https://qlabcookbook.com/1999/01/16/better-by-default/

In some circumstances it is easier to fade in a cue by drawing it  using the integrated fade in the Time& Loops inspector tab of the audio cue. That way you can have all your sounds with a natural sounding fade in programmed when required without worrying about using specific fade cues to bring them in (Think of it like attack on a sampler). If you do this then a crossfade is really only a matter of fading the currently playing sound out. This won't work though when you need to loop the entire sound as the fade portion will repeat each loop iteration.

If you are using a licensed copy of QLab then scripts can speed up the creation of fades and crossfades by a factor of 10.

[Jennifer Gillmor]

This is all amazing information. Thank you. 

The theatre will be running the show on a licensed version of QLab. But I am building it on one that is not.

So, regarding cross-fading, will you please just spell out the steps that the script you provided accomplishes? Just a regular cross-fade to the stereo mains.

Thanks again for being my virtual knight in shining armour!

[micpool]

On Saturday, March 31, 2018 at 1:33:42 AM UTC+1, Jennifer Gillmor wrote:

The theatre will be running the show on a licensed version of QLab. But I am building it on one that is not.

So, regarding cross-fading, will you please just spell out the steps that the script you provided accomplishes? Just a regular cross-fade to the stereo mains.

Sure No Problem. 

Here's the Crossfade 101 for QLab4 Free version

Select audio files:

 

Drag to workspace:

Set Master Level on  Cue 1 to desired level.  You can select it and  set the level using preview Key V and stop it with Key S

Set Master level on cue 2 to infinity

Make 2 fade cues in Workspace (cmd-7, cues menu,  toolbox or toolbar) and set targets by typing cue number into target field or dragging audio cues to fade cues (practice both)

 Set master level of fade cue targeting cue 1 to infinity (out). Tick ' Stop target when done' checkbox. (Do this whenever you fade something out and don't need to fade it back up again)

Play cue 2 (select it and press key V)  Select fade cue which targets cue 2, Set master level of   to desired level (Live preview is on by default so you will hear the level change) Then stop all cues with ESC key

Click  in the far right  of cues 2 and 3  to create auto-continue arrows. Tidy up cue numbers. Change fade times to desired fade duration in the action column.

Play cue 1 then cue 2 to test (using space bar or go button)

Method 2:  (click twice on auto continue-arrows to remove them if trying this after method 1)

Highlight the  3 cues that will make your crossfade.

Make a group cue by clicking the group cue icon  in the toolbar or toolbox, or typing cmd-0. Set its mode to 'Start all Children simultaneously'

Tidy up numbering and give a meaningful name to the group cue:

Test as before.

 Many designers prefer method 2 as it is clearer and allows you to give the cue a meaningful name while retaining the music titles in the  cue list.

Now you have the basic crossfade structure in place you can copy and paste it:

And then retarget the audio cue in the copied group, either by clicking the arrow in the target column, or by dragging files from the finder to the audio cue to replace it:

Finally, retarget the fade in the copied group to target the cue you want to fade out, by dragging the audio cue to the fade cue :

You can copy and paste individual elements e.g the fade and stop cue:

And then retarget the copied fade and stop  by dragging the audio cue you want to fade out and stop  to it:

Renumber and test.

Hope that helps.

Mic