This is actually very easy to do. The basic workflow is very straightforward:
Create a track for the sampled drums. Insert a VST, such as Addictive Drums, Easy Drummer, etc.
In each of the original drum tracks, insert a VST to convert audio data to MIDI data (see below).
Create a send going from each of the original drum tracks to the track containing the sampled drums (remember to disable audio send! Should send only MIDI)
Optional: Configure Addictive Drums to send audio data on separate tracks in reaper, for each piece of the drum kit. Use pre-fader sends, without master send.
Step #2 needs a bit of elaboration, more detail:
It’s not necessary to configure the MIDI channel, but if using a VST with multiple kit pieces, it is necessary to assign which MIDI note will be triggered in the VST. That’s how you tell the plugin to trigger, say, the kick vs the snare (use the MIDI note # for the kick). So on, say, the original kick track, you’ll need to assign the MIDI note for kick (36 in AD2). See MIDI note map for the drum kit pieces MIDI notes assignments.
There are numerous plugins in REAPER that can be used to convert the original audio (original kit pieces) to MIDI and send the MIDI data. My favorite is probably the ReaPlug/JS plugin called JS: Turn audio signal into velocity-sensitive drum trigger.
- Just stick it on, say, your kick drum track, and route as described above. Again, you do want to disable audio on your send, and you do need to know the MIDI note # for the kit piece you’re triggering.
- You can find the thresholds by ear, or use something like Smack Attack to find the threshold. Or use REAPER’s dynamic split >> Set transient sensitivity, and check “display threshold in media items while this window is open.” These will allow you to see, visually, where the threshold needs to be set. Or, like I said, just do it by ear.
- Here’s a detailed tutorial, if interested.
I like that plugin the best. Very easy, accurate and fast. There are numerous other ways to do it:
- Here’s one using JS: Audio to midi drum trigger. Virtually the same setup. Here’s a Kenny tutorial.
- Here’s a video showing how to use ReaGate as a converter.
- This one’s a bit different: you can use dynamic split to separate each drum hit into a separate clip, then actually just replace the clip with another sample. Kenny video tutorial here. It’s a little different than triggering, but pretty straightforward. I haven’t used this method.