I have a track recorded in reaper which I want to variably speed up and slow down as an effect behind my other tracks. Is this an option? Do I need a plugin?
Your best bet with achieving this effect solely with Reaper is to use multiple (background) projects.
Move the audio track to a separate tab. Make sure that you have following options ticked:
- Run background projects
- Play stopped background projects with active project
- *Synchronize play start times w/ play background projects**
Then in the new (background) project you can apply playrate automation. First make sure that master track can be seen (
View > Master Track). From available envelopes select
Playrate and draw the automation values. Something like this:
You may probably want to select "Preserve pitch in audio items when changing master playrate" by right clicking on the
Vari-Speed knob so that you don't get the chipmunk effect.
Manipulating MIDI tracks would be easier, as tempo changes should do the job, though you may still need to resort to background projects.
I'm not really familiar with Reaper, but just tried it out with a short clip and it seems to work. This is not a real automatic way, and if you need to do this often this might not be suitable. Instructions are for the Mac, but PC function naming should be similar.
- Go to the place where you want to start the tempo change (place the playhead there).
Insert -> Time Signature/Tempo Change Marker
- Keep values as they are, place a checkmark next to
Gradually transition tempo to next markerand click
- Go to the place of maximum speed, repeat step 2.
- Change BPM to a desired value and place a checkmark next to
Gradually transition tempo to next marker. Hit
- Repeat step 4-5 on the place of minimum speed. You can do this at multiple points on your track, depending on your speed-up/slow-down needs.
You could try using the
Time Signature/Tempo Change Marker found in the